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Dagilgan S, Dundar-Yenilmez E, Tuli A, Urunsak IF, Erdogan S. Acidosis defense mechanisms in the preimplantation stages of embryos in BALB/c strain mice. Theriogenology 2024; 217:136-142. [PMID: 38277795 DOI: 10.1016/j.theriogenology.2024.01.021] [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: 08/22/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Regulation of intracellular pH (pHi) is an important homeostatic function of cells. There are three major pHi regulatory mechanisms: the HCO3-/Cl- exchanger (AE), which alleviates alkalosis, and the Na+/H+ exchanger (NHE) and Na+,HCO3-/Cl- exchanger (NDBCE), both of which counteract acidosis. NHE activity, which is high at the germinal vesicle stage of oocyte, is inhibited during meiotic maturation, while this inhibition is abolished when the oocyte reaches the pronuclear (PN) stage of the zygote. On the other hand, we have previously found that NDBCE performs complementary regulation against acidosis during meiotic maturation. Additionally, we found that AE activity, which is a defense mechanism against alkalosis, gradually decreases during preimplantation period of embryonic development. Considering that NHE activity is inhibited during meiotic maturation and AE activity gradually decreases during embryonic development stages, we investigated whether NHE and NDBCE activities, both of which act against acidosis, functionally change from the PN zygote to the blastocyst stage of the embryo and identified these pH-regulating proteins at the molecular level in mice of the Balb/c strain. PN zygotes, two-cell (2-c), four-cell (4-c), morula and blastocyst stage embryos were obtained from 5-8-week-old, sexually mature female Balb/c mice by using the classical superovulation procedure. pHi was recorded by using the microspectrofluorometric technique on zygotes and embryos simultaneously loaded with the pH-sensitive fluorophore, 2',7'-Bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). The activities of NHE and NDBCE were determined from the recovery curve of induced-acidosis in bicarbonate-free and bicarbonate-containing media, respectively. Specific inhibitors such as cariporide (1 μM), S3226 (1 and 10 μM), EIPA (1, 5, and 25 μM), and amiloride (1 mM) were used to functionally identify NHE isoforms, and the nonspecific inhibitor 4,4'-diisocyanatostilbene-2,2' disulphonic acid, disodium salt (DIDS) was used to confirm NDBCE activity. The isoforms of the pHi-regulatory proteins were also identified by molecular biology using real-time PCR. We found that NHE activity was high at all embryonic stages, and differences between stages were not significant. Functional and molecular findings indicated that isoforms of NHE 1 and 5 are present in the blastocyst, whereas isoforms of NHE 1, 3, and 4 are functional at earlier embryonic stages. Although the contribution of NDBCE activity to recovery from induced-acidosis was detected at all embryonic stages, it was significant only in the PN zygote and the 2-c embryo. This finding was confirmed by molecular analysis, which detected the expression of SLC4A8 encoding NDBCE at all embryonic stages. In conclusion, NHE is an active and important defense mechanism against acidosis and is encoded by at least two protein isoforms in all stages of the Balb/c strain of mice. NDBCE has a supportive function in all embryonic stages, especially in the PN zygote and the 2-c embryo. Preimplantation stage embryos have effective mechanisms to defend against acidosis in response to their metabolic end products (increased acid load) and the acidic environment in utero.
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Affiliation(s)
- Senay Dagilgan
- Cukurova University Faculty of Medicine, Departments of Physiology, Balcali, 01330, Adana, Turkey
| | - Ebru Dundar-Yenilmez
- Cukurova University Faculty of Medicine, Biochemistry, Balcali, 01330, Adana, Turkey
| | - Abdullah Tuli
- Cukurova University Faculty of Medicine, Biochemistry, Balcali, 01330, Adana, Turkey
| | - Ibrahim Ferhat Urunsak
- Cukurova University Faculty of Medicine, Obstetric and Gynaecology, Balcali, 01330, Adana, Turkey
| | - Seref Erdogan
- Cukurova University Faculty of Medicine, Departments of Physiology, Balcali, 01330, Adana, Turkey.
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Liao S, Wu G, Xie Z, Lei X, Yang X, Huang S, Deng X, Wang Z, Tang G. pH regulators and their inhibitors in tumor microenvironment. Eur J Med Chem 2024; 267:116170. [PMID: 38308950 DOI: 10.1016/j.ejmech.2024.116170] [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: 11/17/2023] [Revised: 01/14/2024] [Accepted: 01/22/2024] [Indexed: 02/05/2024]
Abstract
As an important characteristic of tumor, acidic tumor microenvironment (TME) is closely related to immune escape, invasion, migration and drug resistance of tumor. The acidity of the TME mainly comes from the acidic products produced by the high level of tumor metabolism, such as lactic acid and carbon dioxide. pH regulators such as monocarboxylate transporters (MCTs), carbonic anhydrase IX (CA IX), and Na+/H+ exchange 1 (NHE1) expel protons directly or indirectly from the tumor to maintain the pH balance of tumor cells and create an acidic TME. We review the functions of several pH regulators involved in the construction of acidic TME, the structure and structure-activity relationship of pH regulator inhibitors, and provide strategies for the development of small-molecule antitumor inhibitors based on these targets.
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Affiliation(s)
- Senyi Liao
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Guang Wu
- The Second Affiliated Hospital, Department of Pharmacy, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Zhizhong Xie
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Xiaoyong Lei
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Xiaoyan Yang
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Sheng Huang
- Jiuzhitang Co., Ltd, Changsha, Hunan, 410007, China
| | - Xiangping Deng
- The First Affiliated Hospital, Department of Pharmacy, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Zhe Wang
- The Second Affiliated Hospital, Department of Pharmacy, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Guotao Tang
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
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Chen W, Liu J, Zheng C, Bai Q, Gao Q, Zhang Y, Dong K, Lu T. Research Progress on Improving the Efficiency of CDT by Exacerbating Tumor Acidification. Int J Nanomedicine 2022; 17:2611-2628. [PMID: 35712639 PMCID: PMC9196673 DOI: 10.2147/ijn.s366187] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/16/2022] [Indexed: 12/21/2022] Open
Abstract
In recent years, chemodynamic therapy (CDT) has received extensive attention as a novel means of cancer treatment. The CDT agents can exert Fenton and Fenton-like reactions in the acidic tumor microenvironment (TME), converting hydrogen peroxide (H2O2) into highly toxic hydroxyl radicals (·OH). However, the pH of TME, as an essential factor in the Fenton reaction, does not catalyze the reaction effectively, hindering its efficiency, which poses a significant challenge for the future clinical application of CDT. Therefore, this paper reviews various strategies to enhance the antitumor properties of nanomaterials by modulating tumor acidity. Ultimately, the performance of CDT can be further improved by inducing strong oxidative stress to produce sufficient ·OH. In this paper, the various acidification pathways and proton pumps with potential acidification functions are mainly discussed, such as catalytic enzymes, exogenous acids, CAIX, MCT, NHE, NBCn1, etc. The problems, opportunities, and challenges of CDT in the cancer field are also discussed, thereby providing new insights for the design of nanomaterials and laying the foundation for their future clinical applications.
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Affiliation(s)
- Wenting Chen
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Jinxi Liu
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Caiyun Zheng
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Que Bai
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Qian Gao
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Yanni Zhang
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Kai Dong
- School of Pharmacy, Xi'an Jiaotong University, Xi'an, 710072, People's Republic of China
| | - Tingli Lu
- Key Laboratory for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
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Chung YJ, Park KC, Tokar S, Eykyn TR, Fuller W, Pavlovic D, Swietach P, Shattock MJ. Off-target effects of sodium-glucose co-transporter 2 blockers: empagliflozin does not inhibit Na+/H+ exchanger-1 or lower [Na+]i in the heart. Cardiovasc Res 2021; 117:2794-2806. [PMID: 33135077 PMCID: PMC8683707 DOI: 10.1093/cvr/cvaa323] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/28/2020] [Accepted: 11/02/2020] [Indexed: 12/17/2022] Open
Abstract
AIMS Emipagliflozin (EMPA) is a potent inhibitor of the renal sodium-glucose co-transporter 2 (SGLT2) and an effective treatment for type-2 diabetes. In patients with diabetes and heart failure, EMPA has cardioprotective effects independent of improved glycaemic control, despite SGLT2 not being expressed in the heart. A number of non-canonical mechanisms have been proposed to explain these cardiac effects, most notably an inhibitory action on cardiac Na+/H+ exchanger 1 (NHE1), causing a reduction in intracellular [Na+] ([Na+]i). However, at resting intracellular pH (pHi), NHE1 activity is very low and its pharmacological inhibition is not expected to meaningfully alter steady-state [Na+]i. We re-evaluate this putative EMPA target by measuring cardiac NHE1 activity. METHODS AND RESULTS The effect of EMPA on NHE1 activity was tested in isolated rat ventricular cardiomyocytes from measurements of pHi recovery following an ammonium pre-pulse manoeuvre, using cSNARF1 fluorescence imaging. Whereas 10 µM cariporide produced near-complete inhibition, there was no evidence for NHE1 inhibition with EMPA treatment (1, 3, 10, or 30 µM). Intracellular acidification by acetate-superfusion evoked NHE1 activity and raised [Na+]i, reported by sodium binding benzofuran isophthalate (SBFI) fluorescence, but EMPA did not ablate this rise. EMPA (10 µM) also had no significant effect on the rate of cytoplasmic [Na+]i rise upon superfusion of Na+-depleted cells with Na+-containing buffers. In Langendorff-perfused mouse, rat and guinea pig hearts, EMPA did not affect [Na+]i at baseline nor pHi recovery following acute acidosis, as measured by 23Na triple quantum filtered NMR and 31P NMR, respectively. CONCLUSIONS Our findings indicate that cardiac NHE1 activity is not inhibited by EMPA (or other SGLT2i's) and EMPA has no effect on [Na+]i over a wide range of concentrations, including the therapeutic dose. Thus, the beneficial effects of SGLT2i's in failing hearts should not be interpreted in terms of actions on myocardial NHE1 or intracellular [Na+].
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Affiliation(s)
- Yu Jin Chung
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - Kyung Chan Park
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford, OX1 3PT, UK
| | - Sergiy Tokar
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - Thomas R Eykyn
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
- School of Biomedical Engineering and Imaging Sciences, King’s College London, The Rayne Institute, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - William Fuller
- Institute of Cardiovascular & Medical Sciences, Sir James Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Davor Pavlovic
- Institute for Cardiovascular Sciences, University of Birmingham, Wolfson Drive, Birmingham B15 2TT, UK
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford, OX1 3PT, UK
| | - Michael J Shattock
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
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5
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The Cardioprotective Effects of Novel Na+/H+ Exchanger Inhibitor TY-51924 on Ischemia/Reperfusion Injury. J Cardiovasc Pharmacol 2014; 63:351-9. [DOI: 10.1097/fjc.0000000000000055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hendus-Altenburger R, Kragelund BB, Pedersen SF. Structural dynamics and regulation of the mammalian SLC9A family of Na⁺/H⁺ exchangers. CURRENT TOPICS IN MEMBRANES 2014; 73:69-148. [PMID: 24745981 DOI: 10.1016/b978-0-12-800223-0.00002-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mammalian Na⁺/H⁺ exchangers of the SLC9A family are widely expressed and involved in numerous essential physiological processes. Their primary function is to mediate the 1:1 exchange of Na⁺ for H⁺ across the membrane in which they reside, and they play central roles in regulation of body, cellular, and organellar pH. Their function is tightly regulated through mechanisms involving interactions with multiple protein and lipid-binding partners, phosphorylations, and other posttranslational modifications. Biochemical and mutational analyses indicate that the SLC9As have a short intracellular N-terminus, 12 transmembrane (TM) helices necessary and sufficient for ion transport, and a C-terminal cytoplasmic tail region with essential regulatory roles. No high-resolution structures of the SLC9As exist; however, models based on crystal structures of the bacterial NhaAs support the 12 TM organization and suggest that TMIV and XI may form a central part of the ion-translocation pathway, whereas pH sensing may involve TMII, TMIX, and several intracellular loops. Similar to most ion transporters studied, SLC9As likely exist as coupled dimers in the membrane, and this appears to be important for the well-studied cooperativity of H⁺ binding. The aim of this work is to summarize and critically discuss the currently available evidence on the structural dynamics, regulation, and binding partner interactions of SLC9As, focusing in particular on the most widely studied isoform, SLC9A1/NHE1. Further, novel bioinformatic and structural analyses are provided that to some extent challenge the existing paradigm on how ions are transported by mammalian SLC9As.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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Harguindey S, Arranz JL, Polo Orozco JD, Rauch C, Fais S, Cardone RA, Reshkin SJ. Cariporide and other new and powerful NHE1 inhibitors as potentially selective anticancer drugs--an integral molecular/biochemical/metabolic/clinical approach after one hundred years of cancer research. J Transl Med 2013; 11:282. [PMID: 24195657 PMCID: PMC3826530 DOI: 10.1186/1479-5876-11-282] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 10/25/2013] [Indexed: 02/04/2023] Open
Abstract
In recent years an increasing number of publications have emphasized the growing importance of hydrogen ion dynamics in modern cancer research, from etiopathogenesis and treatment. A proton [H+]-related mechanism underlying the initiation and progression of the neoplastic process has been recently described by different research groups as a new paradigm in which all cancer cells and tissues, regardless of their origin and genetic background, have a pivotal energetic and homeostatic disturbance of their metabolism that is completely different from all normal tissues: an aberrant regulation of hydrogen ion dynamics leading to a reversal of the pH gradient in cancer cells and tissues (↑pHi/↓pHe, or “proton reversal”). Tumor cells survive their hostile microenvironment due to membrane-bound proton pumps and transporters, and their main defensive strategy is to never allow internal acidification because that could lead to their death through apoptosis. In this context, one of the primary and best studied regulators of both pHi and pHe in tumors is the Na+/H+ exchanger isoform 1 (NHE1). An elevated NHE1 activity can be correlated with both an increase in cell pH and a decrease in the extracellular pH of tumors, and such proton reversal is associated with the origin, local growth, activation and further progression of the metastatic process. Consequently, NHE1 pharmaceutical inhibition by new and potent NHE1 inhibitors represents a potential and highly selective target in anticancer therapy. Cariporide, being one of the better studied specific and powerful NHE1 inhibitors, has proven to be well tolerated by humans in the cardiological context, however some side-effects, mainly related to drug accumulation and cerebrovascular complications were reported. Thus, cariporide could become a new, slightly toxic and effective anticancer agent in different human malignancies.
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Affiliation(s)
- Salvador Harguindey
- Instituto de Biología Clínica y Metabolismo (IBCM), Postas 13-01004, Vitoria, Spain.
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Atwal KS, O'Neil SV, Ahmad S, Doweyko L, Kirby M, Dorso CR, Chandrasena G, Chen BC, Zhao R, Zahler R. Synthesis and biological activity of 5-aryl-4-(4-(5-methyl-1H-imidazol-4-yl)piperidin-1-yl)pyrimidine analogs as potent, highly selective, and orally bioavailable NHE-1 inhibitors. Bioorg Med Chem Lett 2006; 16:4796-9. [PMID: 16870436 DOI: 10.1016/j.bmcl.2006.06.077] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 06/22/2006] [Accepted: 06/23/2006] [Indexed: 10/24/2022]
Abstract
A series of potent inhibitors of the sodium hydrogen exchanger-1 (NHE-1) is described. Structure-activity relationships identified the 3-methyl-4-fluoro analog 9t as a highly potent (IC50 = 0.0065 microM) and selective (NHE-2/NHE-1=1400) non-acylguanidine NHE-1 inhibitor. Pharmacokinetic studies showed that compound 9t has an oral bioavailability of 52% and a plasma half life of 1.5 h in rats. Because of its promising potency, selectivity, and a good pharmacokinetic profile, compound 9t was selected for further studies.
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Affiliation(s)
- Karnail S Atwal
- Department of Discovery Chemistry, Bristol-Myers Squibb, Pharmaceutical Research Institute, PO Box 4000, Princeton, NJ 08543-5400, USA
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9
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Ahmad S, Ngu K, Combs DW, Wu SC, Weinstein DS, Liu W, Chen BC, Chandrasena G, Dorso CR, Kirby M, Atwal KS. Aminoimidazoles as bioisosteres of acylguanidines: novel, potent, selective and orally bioavailable inhibitors of the sodium hydrogen exchanger isoform-1. Bioorg Med Chem Lett 2004; 14:177-80. [PMID: 14684323 DOI: 10.1016/j.bmcl.2003.09.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Inhibition of the sodium hydrogen exchanger isoform-1 (NHE-1) has been shown to limit damage to the myocardium under ischemic conditions in animals. While most known NHE-1 inhibitors are acylguanidines, this report describes the design and synthesis of a series of heterocyclic inhibitors of NHE-1 including aminoimidazoles with undiminished in vitro activity and oral bioavailability.
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Affiliation(s)
- Saleem Ahmad
- Bristol-Myers Squibb Pharmaceutical Research Institute, PO Box 4000, Princeton, NJ 08543, USA.
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Tracey WR, Allen MC, Frazier DE, Fossa AA, Johnson CG, Marala RB, Knight DR, Guzman-Perez A. Zoniporide: a potent and selective inhibitor of the human sodium-hydrogen exchanger isoform 1 (NHE-1). CARDIOVASCULAR DRUG REVIEWS 2003; 21:17-32. [PMID: 12595915 DOI: 10.1111/j.1527-3466.2003.tb00103.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The sodium-hydrogen exchanger isoform-1 (NHE-1) plays an important role in the myocardial response to ischemia-reperfusion; inhibition of this exchanger protects against ischemic injury, including reduction in infarct size. Herein we describe a novel, potent, and highly selective NHE-1 inhibitor, zoniporide (CP-597,396; [1-(quinolin-5-yl)-5-cyclopropyl-1H-pyrazole-4-carbonyl] guanidine). Zoniporide inhibits human NHE-1 with an IC(50) of 14 nM, has >150-fold selectivity vs. other NHE isoforms, and potently inhibits ex vivo NHE-1-dependent swelling of human platelets. This compound is well tolerated in preclinical animal models, exhibits moderate plasma protein binding, has a t(1/2) of 1.5 h in monkeys, and has one major active metabolite. In both in vitro and in vivo rabbit models of myocardial ischemia-reperfusion injury, zoniporide markedly reduced infarct size without adversely affecting hemodynamics or cardiac function. In the isolated heart (Langendorff), zoniporide elicited a concentration-dependent reduction in infarct size (EC(50) = 0.25 nM). At 50 nM it reduced infarct size by 83%. This compound was 2.5-20-fold more potent than either eniporide or cariporide (EC(50)s of 0.69 and 5.11 nM, respectively), and reduced infarct size to a greater extent than eniporide. In open chest, anesthetized rabbits, zoniporide also elicited a dose-dependent reduction in infarct size (ED(50) = 0.45 mg/kg/h) and inhibited NHE-1-mediated platelet swelling (93% inhibition at 4 mg/kg/h). Furthermore, zoniporide attenuated postischemic cardiac contractile dysfunction in conscious primates, and reduced both the incidence and duration of ischemia-reperfusion-induced ventricular fibrillation in rats. Zoniporide represents a novel class of potent and selective human NHE-1 inhibitors with potential utility for providing cardioprotection in a clinical setting.
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Affiliation(s)
- W Ross Tracey
- Pfizer Global Research and Development, Groton, CT 06340, USA.
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Ryan JB, Hicks M, Cropper JR, Garlick SR, Kesteven SH, Wilson MK, Feneley MP, Macdonald PS. Cariporide (HOE-642) improves cardiac allograft preservation in a porcine model of orthotopic heart transplantation. Transplantation 2003; 75:625-31. [PMID: 12640300 DOI: 10.1097/01.tp.0000054619.13962.30] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Acute graft dysfunction caused by ischemia-reperfusion injury is recognized as a major source of morbidity and mortality following adult heart transplantation. The aim of this study was to determine whether treating the donor and recipient with cariporide, an inhibitor of the sodium-hydrogen exchanger, could reduce ischemia-reperfusion injury. METHODS A porcine model of donor brain death, hypothermic ischemic preservation, and orthotopic cardiac transplantation was used. Allografts in both the control group (CON, n=6) and treatment group (CAR, n=6) were arrested and stored for 4 hours in the extracellular crystalloid cardioplegia currently used in the clinical transplantation program at our institution. In addition, both the donor and recipient animals in the CAR group received a single intravenous dose of cariporide (2 mg/kg) 15 minutes before harvesting and reperfusion, respectively. RESULTS The initial rate of troponin I release was significantly lower in recipients of CAR hearts than in recipients of CON hearts (P =0.020). All hearts were weaned successfully from bypass. More CAR hearts were weaned successfully at the first attempt, at 1 hour post-reperfusion, than CON hearts (6 of 6 vs 3 of 6), but this did not achieve statistical significance. Left ventricular contractility (preload recruitable stroke-work relationship) and left ventricular compliance (end-diastolic pressure-volume relationship) were significantly better preserved in CAR hearts than CON hearts (both P <0.0001). CONCLUSIONS Myocardial injury was reduced, and contractile function was better preserved in allografts that received cariporide, compared with allografts that received conventional preservation alone.
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Affiliation(s)
- Jonathon B Ryan
- Department of Heart and Lung Transplantation, St. Vincent's Hospital, Darlinghurst, Australia
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12
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Touret N, Tanneur V, Godart H, Seidler R, Taki N, Bürger E, Dämmgen J, Counillon L. Characterization of sabiporide, a new specific NHE-1 inhibitor exhibiting slow dissociation kinetics and cardioprotective effects. Eur J Pharmacol 2003; 459:151-8. [PMID: 12524140 DOI: 10.1016/s0014-2999(02)02824-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Sabiporide, a new benzoguanidine, was characterized on fibroblasts stably expressing the Na(+)/H(+) exchanger isoforms NHE-1, NHE-2 and NHE-3. 22Na(+) uptake experiments show that this compound possesses a K(i) of 5+/-1.2 x 10(-8) M for NHE-1, and discriminates efficiently between the NHE-1, -2 and -3 isoforms (K(i) for NHE-2: 3+/-0.9 x 10(-6) M, and K(i)>1 mM for NHE-3). Similar K(i) values are obtained on rat cardiomyocytes and human platelets expressing NHE-1 (K(i)'s of 7+/-1 x 10(-9) and 2.7+/-0.4 x 10(-8) M respectively). Interestingly, when compared with amiloride and cariporide, sabiporide inhibition persists even after this molecule had been rinsed out (half time of 7 h for sabiporide, and of 1 and 2.5 min for amiloride and cariporide, respectively), the decay of all these molecules exhibiting a complex multiexponential behavior. Thus, sabiporide, which possesses remarkable cardioprotective properties, is a specific NHE-1 inhibitor possessing unique binding kinetics.
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Affiliation(s)
- Nicolas Touret
- Laboratoire de Physiologie Cellulaire et Moléculaire, CNRS UMR6548, Université de Nice-Sophia Antipolis, Faculté des Sciences, Parc Valrose, 06108 cedex 2, Nice, France
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Kusumoto K, Igata H, Abe A, Ikeda S, Tsuboi A, Imamiya E, Fukumoto S, Shiraishi M, Watanabe T. In vitro and in vivo pharmacology of a structurally novel Na+-H+ exchange inhibitor, T-162559. Br J Pharmacol 2002; 135:1995-2003. [PMID: 11959803 PMCID: PMC1573312 DOI: 10.1038/sj.bjp.0704647] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. We investigated the inhibitory effects of a non-acylguanidine Na(+)-H(+) exchange (NHE) inhibitor, T-162559 ((5E,7S)-[7-(5-fluoro-2-methylphenyl)-4-methyl-7,8-dihydro-5(6H)-quinolinylideneamino] guanidine dimethanesulphonate), on NHE-1, and its cardioprotective effect against ischaemia and reperfusion injury in rats and rabbits. 2. T-162559 inhibited human platelet NHE-1 in a concentration-dependent manner, with an IC(50) value of 13+/-3 nmol l(-1), making it 16 and three times more potent than cariporide IC(50): 209+/-75 nmol l(-1), P<0.01) and eniporide (IC(50): 40+/-11 nmol l(-1), P=0.066), respectively. T-162559 also inhibited rat NHE-1 with an IC(50) value of 14+/-2 nmol l(-1), which was five and three times lower than that of cariporide (IC(50): 75+/-7 nmol l(-1), P<0.01) and eniporide (IC(50): 44+/-2 nmol l(-1), P<0.01), respectively. 3. T-162559 inhibited, in a concentration-dependent manner, the reduction in cardiac contractility, progression of cardiac contracture, and increase in lactate dehydrogenase release after global ischaemia and reperfusion in perfused rat hearts. The inhibitory effects of T-162559 were observed at a lower concentration range (10 - 100 nmol l(-1)) than with cariporide and eniporide. T-162559 did not alter basal cardiac contractility or coronary flow after reperfusion, suggesting that it exerts direct cardioprotective effects on the heart. 4. Intravenous administration of T-162559 (0.03 and 0.1 mg kg(-1)) significantly inhibited the progression of myocardial infarction induced by left coronary artery occlusion and reperfusion in rabbits; the infarct size normalized by area at risk was 74+/-6% in the vehicle group, and 47+/-5% and 51+/-7% in the T-162559-0.03 mg kg(-1) and T-162559-0.1 mg kg(-1) groups (both P<0.05), respectively. 5. These results indicate that the new structural NHE-1 inhibitor T-162559 is more potent than cariporide and eniporide and possesses a cardioprotective effect against ischaemia and reperfusion injury in rat and rabbit models.
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Affiliation(s)
- Keiji Kusumoto
- Pharmacology Research Laboratories I, Takeda Chemical Industries, LTD., Osaka 532-8686, Japan.
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Beatch GN, Barrett TD, Plouvier B, Jung G, Wall RA, Zolotoy A, Walker MJA. Ventricular fibrillation, an uncontrolled arrhythmia seeking new targets. Drug Dev Res 2002. [DOI: 10.1002/ddr.10038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kawamoto T, Kimura H, Kusumoto K, Fukumoto S, Shiraishi M, Watanabe T, Sawada H. Potent and selective inhibition of the human Na+/H+ exchanger isoform NHE1 by a novel aminoguanidine derivative T-162559. Eur J Pharmacol 2001; 420:1-8. [PMID: 11412833 DOI: 10.1016/s0014-2999(01)00991-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We isolated Na+/H+ exchanger (NHE)-deficient Chinese hamster ovary (CHO-K1) cells stably expressing human NHE isoforms (hNHE1, hNHE2 and hNHE3) and established an assay system for measuring their Na+/H+ exchange activity by monitoring intracellular pH alterations. Using this assay system, we demonstrated that the acylguanidine derivatives, cariporide and eniporide, cause selective inhibition of hNHE1 (IC50 value of 30 nM for cariporide, IC50 value of 4.5 nM for eniporide). Furthermore, we found that a novel synthetic aminoguanidine derivative, T-162559 ((5E,7S)-[7-(5-fluoro-2-methylphenyl)-4-methyl-7,8-dihydro-5(6H)-quinolinylideneamino] guanidine dimethanesulfonate), causes a selective inhibition of hNHE1 with more potent activity than cariporide and eniporide (IC50 value of 0.96 nM). This compound did not affect Na+/HCO3- cotransport and Na+/Ca2+ exchange.
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Affiliation(s)
- T Kawamoto
- Discovery Research Laboratories IV, Pharmaceutical Discovery Research Division, Takeda Chemical Industries, Ltd., 17-85, Jusohonmachi 2-chome, Yodogawa-ku, 532-8686, Osaka, Japan.
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Affiliation(s)
- D Barrett
- Fujisawa Pharmaceutical Company, 2-1-6 Kashima, Yodogawa-ku, 532-8514, Tel: +81 6 6390 12856; fax: +81 6 6304 5435, Osaka, Japan
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