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Shinohara Y, Komiya Y, Morimoto K, Endo Y, Terashima M, Suzuki T, Takino T, Ninomiya I, Yamada H, Uto Y. Development of UTX-143, a selective sodium-hydrogen exchange subtype 5 inhibitor, using amiloride as a lead compound. Bioorg Med Chem 2024; 99:117603. [PMID: 38246115 DOI: 10.1016/j.bmc.2024.117603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/06/2024] [Accepted: 01/11/2024] [Indexed: 01/23/2024]
Abstract
NHE5, an isoform of the Na+/H+ exchanger (NHE) protein, is an ion-transporting membrane protein that regulates intracellular pH and is highly expressed in colorectal adenocarcinoma. Therefore, we hypothesized that NHE5 inhibitors can be used as anticancer drugs. However, because NHE1 is ubiquitously expressed in all cells, it is extremely important to demonstrate its selective inhibitory activity against NHE5. We used amiloride, an NHE non-selective inhibitor, as a lead compound and created UTX-143, which has NHE5-selective inhibitory activity, using a structure-activity relationship approach. UTX-143 showed selective cytotoxic effects on cancer cells and reduced the migratory and invasive abilities of cancer cells. These results suggest a new concept wherein drugs exhibit cancer-specific cytotoxic effects through selective inhibition of NHE5 and the possibility of UTX-143 as a lead NHE5-selective inhibitor.
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Affiliation(s)
- Yusei Shinohara
- Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjimacho-2, Tokushima 770-8506, Japan
| | - Yuki Komiya
- Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjimacho-2, Tokushima 770-8506, Japan
| | - Kashin Morimoto
- Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjimacho-2, Tokushima 770-8506, Japan
| | - Yoshio Endo
- Central Research Resource Branch, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Minoru Terashima
- Division of Functional Geneomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Takeshi Suzuki
- Division of Functional Geneomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Takahisa Takino
- Division of Education for Global Standard, Institute of Liberal Arts and Science, Kanazawa University Kakuma-machi, Kanazawa 920-1192, Japan
| | - Itasu Ninomiya
- Director of Central Medical Center and Department of Surgery, Fukui Prefectural Hospital, Yotsui-2, Fukui 910-0846, Japan
| | - Hisatsugu Yamada
- Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjimacho-2, Tokushima 770-8506, Japan
| | - Yoshihiro Uto
- Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjimacho-2, Tokushima 770-8506, Japan.
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Gei L, Yan Y, Xing W, Li Q, Chen X, Yan F, Wang Y, Cao Y, Jiang W, E R, Luo D, Zhang Y, Zeng W, Chen D. Amiloride alleviates morphine tolerance by suppressing ASIC3-dependent neuroinflammation in the spinal cord. Eur J Pharmacol 2024; 963:176173. [PMID: 37918499 DOI: 10.1016/j.ejphar.2023.176173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
BACKGROUND The use of morphine in clinical medicine is severely constrained by tolerance. Therefore, it is essential to examine pharmacological therapies that suppress the development of morphine tolerance. Amiloride suppressed the expression of inflammatory cytokines by inhibiting microglial activation. Microglia play a crucial role in the establishment of morphine tolerance. Thus, we anticipated that amiloride might suppress the development of morphine tolerance. During this investigation, we assessed the impact of amiloride on mouse morphine tolerance. METHODS Mice received morphine (10 mg/kg, s.c.) twice daily with intrathecally injected amiloride (0.3 μg/5 μl, 1 μg/5 μl, and 3 μg/5 μl) for nine continuous days. To assess morphine tolerance, mice underwent the tail-flick and hot plate tests. BV-2 cells were used to investigate the mechanism of amiloride. By using Western blotting, real-time PCR, and immunofluorescence labeling methods, the levels of acid-sensing ion channels (ASICs), nuclear factor kappa B (NF-kB) p65, p38 mitogen-activated protein kinase (MAPK) proteins, and neuroinflammation-related cytokines were determined. RESULTS The levels of ASIC3 in the spinal cord were considerably increased after long-term morphine administration. Amiloride was found to delay the development of tolerance to chronic morphine assessed via tail-flick and hot plate tests. Amiloride reduced microglial activation and downregulated the cytokines IL-1β and TNF-a by inhibiting ASIC3 in response to morphine. Furthermore, amiloride reduced p38 MAPK phosphorylation and inhibited NF-κB expression. CONCLUSIONS Amiloride effectively reduces chronic morphine tolerance by suppressing microglial activation caused by morphine by inhibiting ASIC3.
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Affiliation(s)
- Liba Gei
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China; Department of Anaesthesiology, Peking University Cancer Hospital (Inner Mongolia Campus)/Affiliated Cancer Hospital of Inner Mongolia Medical University/Inner Mongolia Autonomous Region Cancer Hospital, Hohhot, 010010, China
| | - Yan Yan
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China; Department of Anaesthesiology, Huizhou Municipal Central Hospital, Huizhou, 516001, China
| | - Wei Xing
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - Qiang Li
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - Xiangnan Chen
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China; Department of Anaesthesiology, Guangdong Women and Children Hospital, Guangzhou, 510060, China
| | - Fang Yan
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - Yan Wang
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - Yan Cao
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - Wenqi Jiang
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China
| | - RiQi E
- Department of Anaesthesiology, Peking University Cancer Hospital (Inner Mongolia Campus)/Affiliated Cancer Hospital of Inner Mongolia Medical University/Inner Mongolia Autonomous Region Cancer Hospital, Hohhot, 010010, China
| | - DeXing Luo
- Department of Anaesthesiology, Huizhou Municipal Central Hospital, Huizhou, 516001, China
| | - YanHong Zhang
- Department of Anaesthesiology, Peking University Cancer Hospital (Inner Mongolia Campus)/Affiliated Cancer Hospital of Inner Mongolia Medical University/Inner Mongolia Autonomous Region Cancer Hospital, Hohhot, 010010, China
| | - Weian Zeng
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China.
| | - Dongtai Chen
- Department of Anaesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China.
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Hrvat A, Schmidt M, Wagner B, Zwanziger D, Kimmig R, Volbracht L, Brandau S, Mallmann-Gottschalk N. Electrolyte imbalance causes suppression of NK and T cell effector function in malignant ascites. J Exp Clin Cancer Res 2023; 42:235. [PMID: 37684704 PMCID: PMC10485936 DOI: 10.1186/s13046-023-02798-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/13/2023] [Indexed: 09/10/2023] Open
Abstract
BACKGROUND Malignant ascites commonly occurs in advanced or recurrent stages of epithelial ovarian cancer during peritoneal carcinomatosis and is correlated with poor prognosis. Due to its complex composition of cellular and acellular components malignant ascites creates a unique tumor microenvironment, which mediates immunosuppression and promotes progression of disease. However, the immunosuppressive mechanisms remain poorly understood. METHODS In the present study, we explored the antitumor activity of healthy donor NK and T cells directed against ovarian cancer cells in presence of malignant ascites derived from patients with advanced or recurrent peritoneal carcinomatosis. A wide range of methods was used to study the effect of ascites on NK and T cells (FACS, ELISA, EliSpot, qPCR, Live-cell and confocal microscopy, Western blot and electrolyte flux assays). The ascites components were assessed using quantitative analysis (nephelometry, potentiometry and clinical chemistry) and separation methods (dialysis, ultracentrifugal filtration and lipid depletion). RESULTS Ascites rapidly inhibited NK cell degranulation, tumor lysis, cytokine secretion and calcium signaling. Similarly, target independent NK and T cell activation was impaired in ascites environment. We identified imbalanced electrolytes in ascites as crucial factors causing extensive immunosuppression of NK and T cells. Specifically, high sodium, low chloride and low potassium content significantly suppressed NK-mediated cytotoxicity. Electrolyte imbalance led to changes in transcription and protein expression of electrolyte channels and impaired NK and T cell activation. Selected inhibitors of sodium electrolyte channels restored intracellular calcium flux, conjugation, degranulation and transcript expression of signaling molecules. The levels of ascites-mediated immunosuppression and sodium/chloride/potassium imbalance correlated with poor patient outcome and selected molecular alterations were confirmed in immune cells from ovarian cancer patients. CONCLUSION Our data suggest a novel electrolyte-based mechanism of immunosuppression in malignant ascites of patients with peritoneal carcinomatosis. We show for the first time that the immunosuppression of NK cytotoxicity in coculture assays is correlated to patient poor survival. Therapeutic application of sodium channel inhibitors may provide new means for restoring immune cell activity in ascites or similar electrolyte imbalanced environments.
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Affiliation(s)
- Antonio Hrvat
- Experimental and Translational Research, Department of Otorhinolaryngology, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany
| | - Mathias Schmidt
- Experimental and Translational Research, Department of Otorhinolaryngology, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany
| | - Bernd Wagner
- Department of Clinical Chemistry, University Hospital Essen, 45147, Essen, Germany
| | - Denise Zwanziger
- Department of Clinical Chemistry, University Hospital Essen, 45147, Essen, Germany
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, 45147, Essen, Germany
| | - Rainer Kimmig
- Department of Gynecology and Obstetrics, University Hospital Essen, 45147, Essen, Germany
| | - Lothar Volbracht
- Department of Clinical Chemistry, University Hospital Essen, 45147, Essen, Germany
| | - Sven Brandau
- Experimental and Translational Research, Department of Otorhinolaryngology, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany.
- partner site Essen-Düsseldorf, German Cancer Consortium (DKTK), 45147, Essen, Germany.
| | - Nina Mallmann-Gottschalk
- Experimental and Translational Research, Department of Otorhinolaryngology, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany
- Department of Gynecology and Obstetrics, University Hospital of Cologne, 50931, Cologne, Germany
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Zhang L, Wang X, Chen J, Sheng S, Kleyman TR. Extracellular intersubunit interactions modulate epithelial Na + channel gating. J Biol Chem 2023; 299:102914. [PMID: 36649907 PMCID: PMC9975279 DOI: 10.1016/j.jbc.2023.102914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/13/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023] Open
Abstract
Epithelial Na+ channels (ENaCs) and related channels have large extracellular domains where specific factors interact and induce conformational changes, leading to altered channel activity. However, extracellular structural transitions associated with changes in ENaC activity are not well defined. Using crosslinking and two-electrode voltage clamp in Xenopus oocytes, we identified several pairs of functional intersubunit contacts where mouse ENaC activity was modulated by inducing or breaking a disulfide bond between introduced Cys residues. Specifically, crosslinking E499C in the β-subunit palm domain and N510C in the α-subunit palm domain activated ENaC, whereas crosslinking βE499C with αQ441C in the α-subunit thumb domain inhibited ENaC. We determined that bridging βE499C to αN510C or αQ441C altered the Na+ self-inhibition response via distinct mechanisms. Similar to bridging βE499C and αQ441C, we found that crosslinking palm domain αE557C with thumb domain γQ398C strongly inhibited ENaC activity. In conclusion, we propose that certain residues at specific subunit interfaces form microswitches that convey a conformational wave during ENaC gating and its regulation.
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Affiliation(s)
- Lei Zhang
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xueqi Wang
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jingxin Chen
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shaohu Sheng
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| | - Thomas R Kleyman
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Zhao J, Wu F, He Q, Feng Y. Enhanced degradation of amiloride over Bi 2FeNbO 7/bisulfite process: Key factors and mechanism. Chemosphere 2022; 300:134573. [PMID: 35436455 DOI: 10.1016/j.chemosphere.2022.134573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/13/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
Construction of Bi2FeNbO7/bisulfite system for abatement of pharmaceutical residue was achieved. An attempt to synthesize Bi2FeNbO7 through hydrothermal technique was confirmed by X-ray diffraction. The magnetic field experiment revealed that Bi2FeNbO7 possessed a saturation magnetization of 6.99 emu/g, indicating magnetic attributes of Bi2FeNbO7. Scanning electron microscopy images showed that Bi2FeNbO7 exhibited regular octahedra in the size of 200-300 nm. In a self-made device, the activation of sodium bisulfite using Bi2FeNbO7 for the disposal of amiloride has been carefully explored. The effects of solution pH, sodium bisulfite concentration, Bi2FeNbO7 dosage, amiloride concentration, coexisting ions, and water matrix on the performance of Bi2FeNbO7/bisulfite system was investigated. The catalytic performance of Bi2FeNbO7/bisulfite to degrade amiloride was considerably higher than that of traditional iron oxides. The maximum removal efficiency of amiloride was 97.9% in Bi2FeNbO7/bisulfite process. The involvement of Fe might be crucial for activating bisulfite to create active species. The dominating radical in Bi2FeNbO7/bisulfite process was identified as SO3•‒. With the help of UHPLC/MS/MS, three new degradation products of amiloride were found. Dehalogenation and deamination of amiloride might account for the formation of these transformation products. This work provides a highly efficient Bi2FeNbO7/bisulfite process for the disposal of pharmaceutical pollutants in water treatment.
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Affiliation(s)
- Jie Zhao
- Department of Applied Chemistry, Xi'an University of Technology, 5 Jinhua South Road, Xi'an, Shaanxi, 710048, PR China.
| | - Fei Wu
- Department of Applied Chemistry, Xi'an University of Technology, 5 Jinhua South Road, Xi'an, Shaanxi, 710048, PR China
| | - Qiang He
- Technical Center, Xi'an Customs District, Shaanxi, 710068, PR China
| | - Yawei Feng
- Department of Applied Chemistry, Xi'an University of Technology, 5 Jinhua South Road, Xi'an, Shaanxi, 710048, PR China
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Chaudhary S, Kumar P, Kaushik M. Exploring the interaction of guanidine ligands Amiloride, Rimeporide and Cariporide with DNA for understanding their role as inhibitors of Na +/H + exchangers (NHEs): A spectroscopic and molecular docking investigation. Int J Biol Macromol 2022; 213:834-844. [PMID: 35675859 DOI: 10.1016/j.ijbiomac.2022.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/26/2022] [Accepted: 06/02/2022] [Indexed: 11/05/2022]
Abstract
The inhibition of Na+/H+ Exchangers (NHEs) has shown efficacy in the pathology of several diseases like tumors, cardiovascular, and neurological disorders. The role of guanidine ligands such as amiloride, cariporide, and rimeporide as NHE inhibitors is very well documented but their interaction studies with genomic DNA are still unexplored. In this study, a combination of various biophysical and molecular docking studies was employed to investigate their binding aspects.UV-Visible, fluorescence, and circular dichroism (CD) studies indicated that guanidine ligands bind to the grooves of Calf Thymus DNA (ctDNA). Fluorescence titration studies depict that amiloride binds to ctDNA with a binding constant in the order of 102 M-1 and free energy change (ΔG0) of -14.05 KJ mol-1. Competitive fluorescence studies indicated the minor groove binding property of amiloride, whereas major groove binding mode was deduced for rimeporide and cariporide. Molecular docking studies were also found to be in accordance with the experimental results, revealing the information about the binding energy of the guanidine ligand-ctDNA complex. The docked structures depicted binding energy of -6.4 kcal mol-1 for amiloride and - 6.6 kcal mol-1 for rimeporide and cariporide. Such physicochemical studies of DNA-ligand interactions may facilitate the understanding of the mechanisms of NHE inhibition.
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Affiliation(s)
- Swati Chaudhary
- Department of Applied Sciences, Maharaja Surajmal Institute of Technology, GGSIP University, New Delhi 110058, India
| | - Pankaj Kumar
- Department of Chemistry, University of Delhi, Delhi 110007, India; Nano-bioconjugate Chemistry Lab, Cluster Innovation Centre, University of Delhi, Delhi 110007, India
| | - Mahima Kaushik
- Nano-bioconjugate Chemistry Lab, Cluster Innovation Centre, University of Delhi, Delhi 110007, India.
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Kawasaki T, Kaneko C, Nakanishi R, Moriyama Y, Nabekura T. Amiloride is a suitable fluorescent substrate for the study of the drug transporter human multidrug and toxin extrusion 1 (MATE1). Biochem Biophys Res Commun 2022; 592:113-8. [PMID: 35042121 DOI: 10.1016/j.bbrc.2022.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 01/06/2022] [Indexed: 11/24/2022]
Abstract
Human multidrug and toxin extrusion 1 (MATE1; SLC47A1) is highly expressed in the kidneys and the liver. It plays a significant role in drug and endogenous compound disposition, and therefore, a rapid evaluation of its inhibition is important for drug development and for the understanding of renal and hepatic physiology. Amiloride is a potassium-sparing diuretic used for treating hypertension; it also demonstrates strong fluorescence in organic solvent or detergent solutions. In this study, we investigated the transport characteristics of amiloride by human MATE1. Cellular accumulation of amiloride was evaluated in control vector- or MATE1-transfected HEK293 cells. Cells were lysed with 1% sodium dodecyl sulfate, and fluorescence was measured using a microplate reader at wavelengths of 364ex and 409em. With ammonium prepulse-induced intracellular acidification, MATE1 transported amiloride at an extracellular pH of 7.4. The uptake demonstrated an overshoot phenomenon and saturated, with the Km and Vmax being 23.5 μM and 1.01 nmol/mg/min, respectively. MATE1-mediated amiloride transport also presented with a bell-shaped pH profile that reached a maximum pH value of 7.4. The inhibitor sensitivity of MATE1-facilitated amiloride transport was similar to those of known substrates, such as tetraethylammonium and metformin. Among the tested inhibitors, pyrimethamine demonstrated the most potent inhibition with an IC50 value of 0.266 μM. Furthermore, MATE1 was found to be inhibited by fampridine, which was previously considered to be a non-inhibitor of MATE1. This study demonstrates that amiloride is a suitable fluorescent substrate for the in vitro study of the transport activity of MATE1.
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Adedara IA, Costa FV, Biasuz E, Canzian J, Farombi EO, Rosemberg DB. Influence of acid-sensing ion channel blocker on behavioral responses in a zebrafish model of acute visceral pain. Behav Brain Res 2022; 416:113565. [PMID: 34499933 DOI: 10.1016/j.bbr.2021.113565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/03/2021] [Accepted: 08/25/2021] [Indexed: 11/25/2022]
Abstract
Acid-sensing ion channels (ASICs) play significant roles in numerous neurological and pathological conditions, including pain. Although acid-induced nociception has been characterized previously in zebrafish, the contribution of ASICs in modulating pain-like behaviors is still unknown. Here, we investigated the role of amiloride, a nonselective ASICs blocker, in the negative modulation of specific behavioral responses in a zebrafish-based model of acute visceral pain. We verified that intraperitoneal injection (i.p.) of 0.25, 0.5, 1.0, and 2.0 mg/mL amiloride alone or vehicle did not change zebrafish behavior compared to saline-treated fish. Administration of 2.5% acetic acid (i.p.) elicited writhing-like response evidenced by the abnormal body curvature and impaired locomotion and motor activity. Attenuation of acetic acid-induced pain was verified at lower amiloride doses (0.25 and 0.5 mg/mL) whereas 1.0 and 2.0 mg/mL abolished pain-like responses. The protective effect of the highest amiloride dose tested was evident in preventing writhing-like responses and impaired locomotion and vertical activity. Collectively, amiloride antagonized abdominal writhing-like phenotype and aberrant behaviors, supporting the involvement of ASICs in a zebrafish-based model of acute visceral pain.
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Affiliation(s)
- Isaac A Adedara
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Natural and Exact Sciences Center, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences, Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria.
| | - Fabiano V Costa
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Natural and Exact Sciences Center, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences, Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Eduarda Biasuz
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Natural and Exact Sciences Center, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Julia Canzian
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Natural and Exact Sciences Center, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences, Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil
| | - Ebenezer O Farombi
- Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Denis B Rosemberg
- Laboratory of Experimental Neuropsychobiology, Department of Biochemistry and Molecular Biology, Natural and Exact Sciences Center, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; Graduate Program in Biological Sciences, Toxicological Biochemistry, Federal University of Santa Maria, 1000 Roraima Avenue, Santa Maria, RS 97105-900, Brazil; The International Zebrafish Neuroscience Research Consortium (ZNRC), 309 Palmer Court, Slidell, LA 70458, USA.
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9
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Abbasloo E, Abdollahi F, Saberi A, Esmaeili-Mahani S, Kaeidi A, Akhlaghinasab F, Sheibani V, Thomas TC, Kobeissy FH, Oryan S. Involvement of T-type calcium channels in the mechanism of low dose morphine-induced hyperalgesia in adult male rats. Neuropeptides 2021; 90:102185. [PMID: 34419803 DOI: 10.1016/j.npep.2021.102185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/19/2021] [Accepted: 08/09/2021] [Indexed: 11/23/2022]
Abstract
It has been shown that systemic and local administration of ultra-low dose morphine induced a hyperalgesic response via mu-opioid receptors. However, its exact mechanism(s) has not fully been clarified. It is documented that mu-opioid receptors functionally couple to T-type voltage dependent Ca+2 channels. Here, we investigated the role of T-type calcium channels, amiloride and mibefradil, on the induction of low-dose morphine hyperalgesia in male Wistar rats. The data showed that morphine (0.01 μg i.t. and 1 μg/kg i.p.) could elicit hyperalgesia as assessed by the tail-flick test. Administration of amiloride (5 and 10 μg i.t.) and mibefradil (2.5 and 5 μg i.t.) completely blocked low-dose morphine-induced hyperalgesia in spinal dorsal horn. Amiloride at doses of 1 and 5 mg/kg (i.p.) and mibefradil (9 mg/kg ip) 10 min before morphine (1 μg/kg i.p.) inhibited morphine-induced hyperalgesia. Our results indicate a role for T-type calcium channels in low dose morphine-induced hyperalgesia in rats.
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Affiliation(s)
- Elham Abbasloo
- Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran.
| | - Farzaneh Abdollahi
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences. Kerman, Iran
| | - Arezoo Saberi
- Neuroscience Research Center, Institute of neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | | | - Ayat Kaeidi
- Physiology-Pharmacology Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Fereshteh Akhlaghinasab
- Physiology Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences. Kerman, Iran
| | - Vahid Sheibani
- Neuroscience Research Center, Institute of neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Theresa Currier Thomas
- College of Medicine-Phoenix, University of Arizona, Child Health, Phoenix, USA; BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix Children's Hospital, Phoenix, USA
| | - Firas Hosni Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Lebanon
| | - Shahrbanoo Oryan
- Departments of Biology, Science and Research Branch, Islamic Azad University. Tehran, Iran
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10
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Ali AE, Elsherbiny DM, Azab SS, El-Demerdash E. The diuretic amiloride attenuates doxorubicin-induced chemobrain in rats: Behavioral and mechanistic study. Neurotoxicology 2021; 88:1-13. [PMID: 34656704 DOI: 10.1016/j.neuro.2021.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 10/08/2021] [Accepted: 10/12/2021] [Indexed: 11/26/2022]
Abstract
Cognitive impairment or "chemobrain" is a troublesome adverse effect which had been increasingly reported by cancer patients after doxorubicin (DOX) chemotherapy. Notably, Hypertension, a very common comorbidity in cancer patients, could pose a greater risk for negative cognitive outcomes. Amiloride (AML) is an antihypertensive, potassium-sparing diuretic that has been proven to be neuroprotective in different experimental models; this can be attributed to its ability to inhibit different ion transporters such as Na+/H+ exchanger (NHE), which upon excessive activation can result in intracellular cationic overload, followed by oxidative damage and cellular death. Accordingly, this study was designed to investigate the potential neuroprotective effect of AML against DOX-induced chemobrain and to elucidate possible underlying mechanisms. Briefly, Histopathological examination and neurobehavioral testing (Morris water maze, Y maze and passive avoidance test) showed that AML co-treatment (10 mg/kg/day) markedly attenuated DOX (2 mg/kg/week)-induced neurodegeneration and memory impairment after 4 weeks of treatments. We found that DOX administration up-regulated NHE expression and increased lactic acid content in the hippocampus which were markedly opposed by AML. Moreover, AML mitigated DOX-induced neuroinflammation and decreased hippocampal tumor necrosis factor-α level, nuclear factor kappa-B, and cyclooxygenase-2 expression. Additionally, AML counteracted DOX-induced hippocampal oxidative stress as indicated by normalized malondialdehyde and glutathione levels. Furthermore, AML halted DOX-induced hippocampal apoptosis as evidenced by decreased caspase-3 activity and lower cytochrome c immunoexpression. Our results in addition to the previously reported antitumor effects of AML and its ability to mitigate cancer resistance to DOX therapy could point toward possible new repositioning scenarios of the diuretic AML especially regarding hypertensive cancer patients.
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Affiliation(s)
- Alaa Emam Ali
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Doaa Mokhtar Elsherbiny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Samar S Azab
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Ebtehal El-Demerdash
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
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11
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Hemdan AM. Mathematical Modeling for HPLC Separation and Quantification of an Anti-Hypertensive Combination by Response Surface Methodology. J AOAC Int 2021; 105:623-629. [PMID: 34519824 DOI: 10.1093/jaoacint/qsab123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/31/2021] [Indexed: 11/14/2022]
Abstract
BACKGROUND Determination of a multi-component mixture by HPLC requires many preliminary runs for method development which is both time-consuming and expensive due to the usage of large solvent volumes. OBJECTIVE In the present study, the main objective was to reduce the preliminary runs that are required for optimizing the method conditions and also shorten the run time of analysis to be suitable for quality control laboratories where there is a large number of samples to be analyzed. METHODS That was achieved using Two-factor three-level Response surface experiment which is a multivariate design that predicts the significant factors for optimizing the studied responses. RESULTS The response surface design suggests that both acetonitrile ratio and flow rate are significant factors for full resolution of the studied mixture; atenolol, amiloride, and hydrochlorothiazide. The studied mixture was fully separated and determined in less than 5 min with perfect resolution. CONCLUSION Experimental design is a very beneficial tool for optimization of the method conditions in HPLC, especially if the studied mixture ingredients have overlapping peaks. For atenolol, amiloride, and hydrochlorothiazide, acetonitrile and flow rate were found to be the significant factors that affect the resolution of the studied mixture. HIGHLIGHTS Response surface design is a powerful tool that could be used for predicting the significant factors for separation in HPLC. Optimization of the method conditions was done using a limited number of preliminary runs. The studied ternary mixture was fully separated in less than five minutes with the aid of experimental design.
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Affiliation(s)
- Ahmed M Hemdan
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ahram Canadian University, 6th October, 12451, Egypt
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12
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Abstract
Amiloride is a potassium retaining diuretic and natriuretic which acts by reversibly
blocking luminal epithelial sodium channels (ENaCs) in the late distal tubule and
collecting duct. Amiloride is indicated in oedematous states, and for potassium
conservation adjunctive to thiazide or loop diuretics for hypertension, congestive heart
failure and hepatic cirrhosis with ascites. Historical studies on its use in hypertension
were poorly controlled and there is insufficient data on dose-response. It is clearly
highly effective in combination with thiazide diuretics where it counteracts the adverse
metabolic effects of the thiazides and its use in the Medical Research Council Trial of
Older Hypertensive Patients, demonstrated convincing outcome benefits on stroke and
coronary events. Recently it has been shown to be as effective as spironolactone in
resistant hypertension but there is a real need to establish its potential role in the
much larger number of patients with mild to moderate hypertension in whom there is a
paucity of information with amiloride particularly across an extended dose range.
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Affiliation(s)
- Qianhui Sun
- Imperial College London, Faculty of Medicine, Faculty Building, Level 2, London, UK
| | - Peter Sever
- Imperial College London, National Heart and Lung Institute, ICTEM Building, Level 3, London, UK
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13
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Zhou L, Zhang T, Shao W, Lu R, Wang L, Liu H, Jiang B, Li S, Zhuo H, Wang S, Li Q, Huang C, Lin D. Amiloride ameliorates muscle wasting in cancer cachexia through inhibiting tumor-derived exosome release. Skelet Muscle 2021; 11:17. [PMID: 34229732 PMCID: PMC8258996 DOI: 10.1186/s13395-021-00274-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/23/2021] [Indexed: 12/25/2022] Open
Abstract
Background Cancer cachexia (CAC) reduces patient survival and quality of life. Developments of efficient therapeutic strategies are required for the CAC treatments. This long-term process could be shortened by the drug-repositioning approach which exploits old drugs approved for non-cachexia disease. Amiloride, a diuretic drug, is clinically used for treatments of hypertension and edema due to heart failure. Here, we explored the effects of the amiloride treatment for ameliorating muscle wasting in murine models of cancer cachexia. Methods The CT26 and LLC tumor cells were subcutaneously injected into mice to induce colon cancer cachexia and lung cancer cachexia, respectively. Amiloride was intraperitoneally injected daily once tumors were formed. Cachexia features of the CT26 model and the LLC model were separately characterized by phenotypic, histopathologic and biochemical analyses. Plasma exosomes and muscle atrophy-related proteins were quantitatively analyzed. Integrative NMR-based metabolomic and transcriptomic analyses were conducted to identify significantly altered metabolic pathways and distinctly changed metabolism-related biological processes in gastrocnemius. Results The CT26 and LLC cachexia models displayed prominent cachexia features including decreases in body weight, skeletal muscle, adipose tissue, and muscle strength. The amiloride treatment in tumor-bearing mice distinctly alleviated muscle atrophy and relieved cachexia-related features without affecting tumor growth. Both the CT26 and LLC cachexia mice showed increased plasma exosome densities which were largely derived from tumors. Significantly, the amiloride treatment inhibited tumor-derived exosome release, which did not obviously affect exosome secretion from non-neoplastic tissues or induce observable systemic toxicities in normal healthy mice. Integrative-omics revealed significant metabolic impairments in cachectic gastrocnemius, including promoted muscular catabolism, inhibited muscular protein synthesis, blocked glycolysis, and impeded ketone body oxidation. The amiloride treatment evidently improved the metabolic impairments in cachectic gastrocnemius. Conclusions Amiloride ameliorates cachectic muscle wasting and alleviates cancer cachexia progression through inhibiting tumor-derived exosome release. Our results are beneficial to understanding the underlying molecular mechanisms, shedding light on the potentials of amiloride in cachexia therapy. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-021-00274-5.
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Affiliation(s)
- Lin Zhou
- Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Tong Zhang
- Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Wei Shao
- Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, 361000, China
| | - Ruohan Lu
- Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Lin Wang
- Department of Oncology, Institute of Gastrointestinal Oncology, Zhongshan Hospital, Xiamen University, Xiamen, 361004, China
| | - Haisheng Liu
- Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Bin Jiang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, China
| | - Shiqin Li
- Department of Medical Oncology, Xiang'an Hospital of Xiamen University, Xiamen, China
| | - Huiqin Zhuo
- Department of Gastrointestinal Surgery, The Affiliated Zhongshan Hospital, Xiamen University, Xiamen, 361004, Fujian, China
| | - Suheng Wang
- Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Qinxi Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, China
| | - Caihua Huang
- Research and Communication Center of Exercise and Health, Xiamen University of Technology, Xiamen, 361024, China.
| | - Donghai Lin
- Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. .,High-field NMR Center, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
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14
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Shen W, Alshehri M, Desale S, Wilcox C. The Effect of Amiloride on Proteinuria in Patients with Proteinuric Kidney Disease. Am J Nephrol 2021; 52:368-377. [PMID: 33957621 DOI: 10.1159/000515809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/05/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Proteinuric kidney diseases share an aggressive clinical course of developing end-stage renal disease. However, the treatment is limited. Amiloride, an epithelial sodium channel (ENaC) inhibitor, was reported to reduce proteinuria in animal studies and case reports independent of ENaC inhibition. We hypothesized that amiloride not triamterene (an analog of amiloride) would reduce proteinuria in the patients with proteinuric kidney disease. METHODS Patients with proteinuria >1.0 g/day and estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m2 on a maximum tolerable dose of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers were randomized to receive amiloride 5 mg twice daily or triamterene 50 mg twice daily for 8 weeks, followed by 4 weeks of washout, and then crossed over to the other drug for 8 weeks. The primary outcome was 24-h urine protein reduction. Secondary outcomes were changes in body weight, blood pressure (BP), serum potassium, and eGFR. Data were analyzed by analysis of variance. RESULTS A total of 12 patients completed the study. Amiloride reduced 24-h urine protein by 38.7% (p = 0.002) and decreased systolic BP by 12.3 mm Hg (p = 0.04). Interestingly, triamterene reduced 24 h urine protein as well, by 32.8% (p = 0.02). Triamterene lowered eGFR by 9.0 mL/min/1.73 m2 (p = 0.007), but it was reversible. The average weight change was insignificant in both groups (p = 0.40 and 0.34 respectively). Three patients withdrew the study due to hyperkalemia. CONCLUSIONS Both amiloride and triamterene significantly reduced proteinuria in patients with proteinuric kidney disease. The anti-proteinuric effect was additive to renin-angiotensin-aldosterone system (RAAS) blockade, given all patients were on RAAS blockade. Hyperkalemia was a safety concern. Larger trials might be needed to examine the antiproteinuric effects of ENaC inhibitors.
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Affiliation(s)
- Wen Shen
- Division of Nephrology and Hypertension, Department of Medicine, MedStar Georgetown University Hospital, Washington, District of Columbia, USA
| | - Mohammed Alshehri
- Division of Nephrology and Hypertension, Department of Medicine, MedStar Georgetown University Hospital, Washington, District of Columbia, USA
| | - Sameer Desale
- Division of Nephrology and Hypertension, Department of Medicine, MedStar Georgetown University Hospital, Washington, District of Columbia, USA
| | - Christopher Wilcox
- Division of Nephrology and Hypertension, Department of Medicine, MedStar Georgetown University Hospital, Washington, District of Columbia, USA
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15
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Buckley BJ, Aboelela A, Majed H, Bujaroski RS, White KL, Powell AK, Wang W, Katneni K, Saunders J, Shackleford DM, Charman SA, Cook GM, Kelso MJ, Ranson M. Systematic evaluation of structure-property relationships and pharmacokinetics in 6-(hetero)aryl-substituted matched pair analogs of amiloride and 5-(N,N-hexamethylene)amiloride. Bioorg Med Chem 2021; 37:116116. [PMID: 33799173 DOI: 10.1016/j.bmc.2021.116116] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 10/21/2022]
Abstract
The K+-sparing diuretic amiloride elicits anticancer activities in multiple animal models. During our recent medicinal chemistry campaign aiming to identify amiloride analogs with improved properties for potential use in cancer, we discovered novel 6-(hetero)aryl-substituted amiloride and 5-(N,N-hexamethylene)amiloride (HMA) analogs with up to 100-fold higher potencies than the parent compounds against urokinase plasminogen activator (uPA), one of amiloride's putative anticancer targets, and no diuretic or antikaliuretic effects. Here, we report the systematic evaluation of structure-property relationships (lipophilicity, aqueous solubility and in vitro metabolic stability in human and mouse liver microsomes) in twelve matched pair analogs selected from our 6-substituted amiloride and HMA libraries. Mouse plasma stability, plasma protein binding, Caco-2 cell permeability, cardiac ion channel activity and pharmacokinetics in mice (PO and IV) and rats (IV) are described alongside amiloride and HMA comparators for a subset of the four most promising matched-pair analogs. The findings combined with earlier uPA activity/selectivity and other data ultimately drove selection of two analogs (AA1-39 and AA1-41) that showed efficacy in separate mouse cancer metastasis studies.
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Affiliation(s)
- Benjamin J Buckley
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia; CONCERT-Translational Cancer Research Centre, NSW 2750, Australia.
| | - Ashraf Aboelela
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Hiwa Majed
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Richard S Bujaroski
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Andrew K Powell
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Wen Wang
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Kasiram Katneni
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Jessica Saunders
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, VIC 3052, Australia
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Otago 9016, New Zealand
| | - Michael J Kelso
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Marie Ranson
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia; CONCERT-Translational Cancer Research Centre, NSW 2750, Australia
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16
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Liern M, Colazo A, Vallejo G, Zotta E. Antiproteinuric action of amiloride in paediatric patient with corticoresistant nephrotic syndrome. Nefrologia 2021; 41:304-310. [PMID: 36166246 DOI: 10.1016/j.nefroe.2021.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 11/19/2020] [Indexed: 06/16/2023] Open
Abstract
INTRODUCCION In nephrotic syndrome, increased podocyturia accompanies pathologic proteinuria. The therapeutic regimen with enalapril, losartan and amiloride could reduce both variables. OBJETIVES Evaluate the anti-proteinuric effect of 2 non-immunological therapeutic regimens, the quantitative relationship between podocyturia and proteinuria. MATERIAL AND METHODS We included children aged 4-12 years with corticoresistant nephrotic syndrome, using 2 different schemes: group A, enalapril + losartan, and group B, enalapril + losartan + amiloride. RESULTS In group A, 17 patients completed the study, the initial mean proteinuria was 39 mg/m2/h and mean proteinuria at the end was 24 mg/m2/h, while in group B 14 patients were treated and the initial average proteinuria was 36 mg/m2/h and the end average proteinuria was 13 mg/m2/h. The paired T test showed significant differences in the decrease in proteinuria, for patients in group B without variation in podocyturia. The 2 factors associated with an increase in proteinuria were podocyturia and the time elapsed from the diagnosis of cortico-resistant nephrotic syndrome to the start of treatment anti-proteinuric. CONCLUSIONS The use of amiloride decreased proteinuria, without significantly modifying podocyturia; we did not observe a positive relationship between both variables.
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Affiliation(s)
- Miguel Liern
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina.
| | - Anabella Colazo
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Graciela Vallejo
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Elsa Zotta
- Departamento de Ciencias Fisiológicas IFIBIO Houssay, CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina; Cátedra de Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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Inoue M, Enomoto M, Yoshimura M, Mizowaki T. Pharmacological inhibition of sodium-calcium exchange activates NADPH oxidase and induces infection-independent NETotic cell death. Redox Biol 2021; 43:101983. [PMID: 33933883 PMCID: PMC8105669 DOI: 10.1016/j.redox.2021.101983] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/12/2021] [Accepted: 04/19/2021] [Indexed: 01/03/2023] Open
Abstract
In addition to its function of innate immunity against invading pathogens, neutrophil extracellular traps (NETs) promote thrombosis, autoimmune disease, and cancer metastasis; therefore, unnecessary exposure to the triggers of infection-independent NET generation should be avoided. We herein show that inhibition of forward-mode Na+/Ca2+ exchange by amiloride analogs, 5-(N-ethyl-N-isopropyl)amiloride (EIPA) and 5-(N-Methyl-N-isobutyl)amiloride (MIA), triggers NETotic cell death independently of infectious stimuli. Isolated human neutrophils treated with EIPA and MIA undergo NETotic cell death by an increase of intracellular Ca2+ following activation of NADPH oxidase and the resultant upregulation of intracellular ROS. EIPA- and MIA-mediated intracellular Ca2+ increase is attributed to the competitive binding of EIPA and MIA against Na+ to Na+/Ca2+ exchanger 1 (NCX1). These results demonstrate a new mechanism of infection-independent NET generation and implicate NCX1 as a physiologic regulator of intracellular calcium balance and NETotic cell death. Two of the amiloride analogs, EIPA and MIA, induce NETotic cell death without infectious stimuli. EIPA and MIA inhibit the forward-mode Na+/Ca2+ exchange and promote the intracellular Ca2+ overload. Intracellular Ca2+ overload by EIPA and MIA activates NADPH oxidase, elevates intracellular ROS level, and induces resultant NETotic cell death.
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Affiliation(s)
- Minoru Inoue
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Michio Yoshimura
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takashi Mizowaki
- Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Mandal AKJ, Wenban C, Heer RS, Kho J, Missouris CG. Covid-19, hypokalaemia and the renin-angiotensin-aldosterone system. Ann Med Surg (Lond) 2021; 65:102261. [PMID: 33815782 PMCID: PMC8003453 DOI: 10.1016/j.amsu.2021.102261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 03/24/2021] [Indexed: 11/16/2022] Open
Affiliation(s)
- Amit K J Mandal
- Wexham Park Hospital, Frimley Health NHS Foundation Trust, UK
| | | | - Randeep S Heer
- Wexham Park Hospital, Frimley Health NHS Foundation Trust, UK
| | - Jason Kho
- Wexham Park Hospital, Frimley Health NHS Foundation Trust, UK
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19
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Liern M, Colazo A, Vallejo G, Zotta E. [Antiproteinuric action of amiloride in paediatric patient with corticoresistant nephrotic syndrome]. Nefrologia 2021; 41:304-310. [PMID: 33722403 DOI: 10.1016/j.nefro.2020.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/06/2020] [Accepted: 11/19/2020] [Indexed: 10/21/2022] Open
Abstract
INTRODUCCION In nephrotic syndrome, increased podocyturia accompanies pathologic proteinuria. The therapeutic regimen with enalapril, losartan and amiloride could reduce both variables. OBJETIVES Evaluate the anti-proteinuric effect of 2 non-immunological therapeutic regimens, the quantitative relationship between podocyturia and proteinuria. MATERIAL AND METHODS We included children aged 4 to 12 years with corticoresistant nephrotic syndrome, using 2 different schemes: group A, enalapril+losartan, and group B, enalapril+losartan+amiloride. RESULTS In group A, 17 patients completed the study, the initial mean proteinuria was 39mg/m2/h and mean proteinuria at the end was 24mg/m2/h, while in group B 14 patients were treated and the initial average proteinuria was 36mg/m2/h and the end average proteinuria was 13mg/m2/h. The paired T test showed significant differences in the decrease in proteinuria, for patients in group B without variation in podocyturia. The 2 factors associated with an increase in proteinuria were podocyturia and the time elapsed from the diagnosis of cortico-resistant nephrotic syndrome to the start of treatment anti-proteinuric. CONCLUSIONS The use of amiloride decreased proteinuria, without significantly modifying podocyturia; we did not observe a positive relationship between both variables.
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Affiliation(s)
- Miguel Liern
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina. Jliern@%20yahoo.com
| | - Anabella Colazo
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Graciela Vallejo
- Unidad de Nefrología, Hospital General de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
| | - Elsa Zotta
- Departamento de Ciencias Fisiológicas IFIBIO Houssay, CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina; Cátedra de Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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20
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Fuchs FD, Scala LCN, Vilela-Martin JF, Whelton PK, Poli-de-Figueiredo CE, Pereira E Silva R, Gus M, Bortolotto LA, Consolim-Colombo FM, Schlatter RP, Cesarino JE, Castro I, Figueiredo Neto JA, Chaves H, Steffens AA, Alves JG, Brandão AA, de Sousa MR, Jardim PC, Moreira LB, Franco RS, Gomes MM, Afiune Neto A, Fuchs FC, Sobral Filho DC, Nóbrega AC, Nobre F, Berwanger O, Fuchs SC. Effectiveness of chlorthalidone/ amiloride versus losartan in patients with stage I hypertension and diabetes mellitus: results from the PREVER-treatment randomized controlled trial. Acta Diabetol 2021; 58:215-220. [PMID: 33047257 DOI: 10.1007/s00592-020-01611-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/23/2020] [Indexed: 12/21/2022]
Abstract
AIMS To compare the blood pressure (BP)-lowering efficacy of a chlorthalidone/amiloride combination pill with losartan, during initial management of JNC 7 Stage I hypertension in patients with type 2 diabetes mellitus. METHODS In an a priori subgroup analysis of a randomized, double-blind, controlled trial, volunteers aged 30-70 years, with stage I hypertension and diabetes mellitus, were randomized to 12.5/2.5 mg of chlorthalidone/amiloride (N = 47) or 50 mg of losartan (N = 50), and followed for 18 months in 21 clinical centers. If BP remained uncontrolled after three months, study medication dose was doubled, and if uncontrolled after six months, amlodipine (5 and 10 mg) and propranolol (40 and 80 mg BID) were added as open label drugs in a progressive fashion. RESULTS Systolic BP decreased to a greater extent in participants allocated to diuretics compared to losartan (P < 0.001). After 18 months of follow-up, systolic BP was 128.4 ± 10.3 mmHg in the diuretic group versus 133.5 ± 8.0 in the losartan group (P < 0.01). In the diuretic group, 36 out of 43 participants (83.7%) had a JNC 7 normal BP, compared to 31/47 (66%) in the losartan group (P = 0.089). Serum cholesterol was higher in the diuretic arm at the end of the trial. Other biochemical parameters and reports of adverse events did not differ by treatment. CONCLUSIONS Treatment of hypertension based on a combination of chlorthalidone and amiloride is more effective for BP lowering compared to losartan in patients with diabetes mellitus and hypertension. TRIAL REGISTRATION Clinical trials registration number: NCT00971165.
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Affiliation(s)
- Flávio D Fuchs
- Division of Cardiology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, INCT PREVER, CPC, 5º. and Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-903, Brazil
| | - Luiz C N Scala
- Hospital Universitário Júlio Müller, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | | | - Paul K Whelton
- Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | | | - Ricardo Pereira E Silva
- Hospital Universitário Walter Cantídio, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Miguel Gus
- Division of Cardiology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, INCT PREVER, CPC, 5º. and Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-903, Brazil
| | - Luiz A Bortolotto
- Faculdade de Medicina, Instituto do Coração, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Rosane P Schlatter
- Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - José E Cesarino
- Faculdade de Ciências Farmacêuticas, USP Ribeirão Preto, Ribeirão Prêto, SP, Brazil
| | - Iran Castro
- Instituto de Cardiologia, Av. Princesa Isabel, Porto Alegre, RS, 395, Brazil
| | | | - Hilton Chaves
- Universidade Federal de Pernambuco, Recife, PE, Brazil
| | | | - João G Alves
- Instituto de Medicina Integral Prof Fernando Figueira, Recife, PE, Brazil
| | - Andréa A Brandão
- Universidade Do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Marcos R de Sousa
- Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Paulo C Jardim
- Hospital das Clínicas de Goiânia, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - Leila B Moreira
- Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | | | | | | | - Felipe C Fuchs
- Division of Cardiology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, INCT PREVER, CPC, 5º. and Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-903, Brazil
| | | | | | - Fernando Nobre
- Faculdade de Medicina de Ribeirão Preto, USP Ribeirão Preto, Ribeirão Prêto, SP, Brazil
| | - Otávio Berwanger
- Instituto de Pesquisa, Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
| | - Sandra C Fuchs
- Division of Cardiology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande Do Sul, INCT PREVER, CPC, 5º. and Ramiro Barcelos, 2350, Porto Alegre, RS, 90035-903, Brazil.
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21
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Tang R, Ba G, Li M, Li Z, Ye H, Lin H, Zhang W. Evidence for role of acid-sensing ion channel 1a in chronic rhinosinusitis with nasal polyps. Eur Arch Otorhinolaryngol 2021; 278:2379-2386. [PMID: 33392760 DOI: 10.1007/s00405-020-06521-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/26/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE A variety of inflammatory cells are infiltrated histologically in sinonasal mucosa of chronic rhinosinusitis with nasal polyps (CRSwNP), especially CRSwNP with asthma. Acid-sensing ion channel 1a (ASIC1a) is essential in the process of sensing acidification and triggering inflammation. Whereas, its role and mechanism in CRSwNP remain uncertain. The present study aimed to explore the roles and mechanism of ASIC1a in the pathogenesis of CRSwNP. METHODS Nasal secretions from control subjects, patients with CRSwNP with or without asthma were collected for measuring pH values. Western blotting, real-time PCR and immunohistochemistry (IHC) were employed to assess ASIC1a expression in nasal tissue samples from included subjects. The co-localization of ASIC1a with inflammatory cells was evaluated by immunofluorescence staining. Then, dispersed nasal polyp cells (DNPCs) were cultured under acidified condition (pH 6.0), with or without ASIC1a inhibitor amiloride. Western blotting, real-time PCR, LDH activity kit, and ELISA were performed to assess the effects and mechanisms of stimulators on the cells. RESULTS The pH values were significantly lower in the nasal secretions from patients with CRSwNP with asthma. Significant upregulation of ASIC1a protein, mRNA levels, and positive cells was found in CRSwNP with asthma. ASIC1a was detected in a variety of inflammatory cells. In cultured DNPCs, significant alterations of ASIC1a levels, LDH activity, HIF-1α levels, and inflammatory cytokines were found under acidified condition (pH 6.0), but were prevented by amiloride. CONCLUSION Upregulation of ASIC1a might be essential in the process of sensing acidification and triggering inflammatory response via enhancing HIF-1α expression and LDH activity to activate inflammatory cells in the pathogenesis of CRSwNP, especially in CRSwNP with asthma.
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Affiliation(s)
- Ru Tang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China
| | - Guangyi Ba
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China
| | - Mingxian Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China
| | - Zhipeng Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China
| | - Haibo Ye
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China
| | - Hai Lin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China.
| | - Weitian Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, No. 600 Yishan Road, Shanghai, 200233, People's Republic of China.
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22
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Mellott A, Rockwood J, Zhelay T, Luu CT, Kaitsuka T, Kozak JA. TRPM7 channel activity in Jurkat T lymphocytes during magnesium depletion and loading: implications for divalent metal entry and cytotoxicity. Pflugers Arch 2020; 472:1589-1606. [PMID: 32964285 DOI: 10.1007/s00424-020-02457-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/14/2022]
Abstract
TRPM7 is a cation channel-protein kinase highly expressed in T lymphocytes and other immune cells. It has been proposed to constitute a cellular entry pathway for Mg2+ and divalent metal cations such as Ca2+, Zn2+, Cd2+, Mn2+, and Ni2+. TRPM7 channels are inhibited by cytosolic Mg2+, rendering them largely inactive in intact cells. The dependence of channel activity on extracellular Mg2+ is less well studied. Here, we measured native TRPM7 channel activity in Jurkat T cells maintained in external Mg2+ concentrations varying between 400 nM and 1.4 mM for 1-3 days, obtaining an IC50 value of 54 μM. Maintaining the cells in 400 nM or 8 μM [Mg2+]o resulted in almost complete activation of TRPM7 in intact cells, due to cytosolic Mg2+ depletion. A total of 1.4 mM [Mg2+]o was sufficient to fully eliminate the basal current. Submillimolar concentrations of amiloride prevented cellular Mg2+ depletion but not loading. We investigated whether the cytotoxicity of TRPM7 permeant metal ions Ni2+, Zn2+, Cd2+, Co2+, Mn2+, Sr2+, and Ba2+ requires TRPM7 channel activity. Mg2+ loading modestly reduced cytotoxicity of Zn2+, Co2+, Ni2+, and Mn2+ but not of Cd2+. Channel blocker NS8593 reduced Co2+ and Mn2+ but not Cd2+ or Zn2+ cytotoxicity and interfered with Mg2+ loading as evaluated by TRPM7 channel basal activity. Ba2+ and Sr2+ were neither detectably toxic nor permeant through the plasma membrane. These results indicate that in Jurkat T cells, entry of toxic divalent metal cations primarily occurs through pathways distinct from TRPM7. By contrast, we found evidence that Mg2+ entry requires TRPM7 channels.
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Affiliation(s)
- Alayna Mellott
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Jananie Rockwood
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Charles Tuan Luu
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Taku Kaitsuka
- School of Pharmacy in Fukuoka, International University of Health and Welfare, Enokizu 137-1, Okawa, Fukuoka, Japan
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA.
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23
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De Luca M, Ioele G, Grande F, Platikanov S, Tauler R, Ragno G. Photostability study of multicomponent drug formulations via MCR-ALS: The case of the hydrochlorothiazide- amiloride mixture. J Pharm Biomed Anal 2020; 186:113332. [PMID: 32387749 DOI: 10.1016/j.jpba.2020.113332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/21/2020] [Accepted: 04/21/2020] [Indexed: 01/05/2023]
Abstract
The kinetics and photodegradation mechanism of the pharmaceutical mixture of hydrochlorothiazide (HCT) and amiloride (AML) has been studied in depth using a chemometric approach. Water solutions of HCT and AML, separately or in binary mixtures, were irradiated with forced light at different pH values (3, 7, 9 and 12). Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) modelling has been applied to the experimental data recorded by UV spectrophotometry and HPLC-UV/MS. 78 data sets were collected and their chemometric processing has allowed the simultaneous determination of the behaviour of the two drugs in the mixture when exposed to light and the dependence of their photodegradation kinetics on pH. MCR-ALS has been applied using three different implementations. Soft-MCR-ALS and hybrid Hard/Soft-MCR-ALS have been used to resolve the experimental data and to get the equilibrium and kinetic parameters of the investigated chemical processes. A third implementation of the MCR-ALS method has been used in the analysis of the incomplete data sets obtained when UV spectrophotometric and HPLC-UV/MS data were simultaneously analysed, using a row- and column-wise incomplete augmented data matrix arrangement. In these matrices, information from HPLC-UV detector was used as a bridge between the data recorded by UV spectrophotometry (acid-base and kinetic reactions monitoring) and the data obtained by HPLC-MS.
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Affiliation(s)
- Michele De Luca
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, 87036, Rende, CS, Italy.
| | - Giuseppina Ioele
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, 87036, Rende, CS, Italy
| | - Fedora Grande
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, 87036, Rende, CS, Italy
| | - Stefan Platikanov
- Department of Environmental Chemistry, IDAEA-CSIC, C/Jordi Girona, 18-26, 08034, Barcelona, Spain
| | - Romà Tauler
- Department of Environmental Chemistry, IDAEA-CSIC, C/Jordi Girona, 18-26, 08034, Barcelona, Spain
| | - Gaetano Ragno
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Via P. Bucci, 87036, Rende, CS, Italy
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24
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Martins VM, Helal L, Ferrari F, Bottino LG, Fuchs SC, Fuchs FD. Efficacy of chlorthalidone and hydrochlorothiazide in combination with amiloride in multiple doses on blood pressure in patients with primary hypertension: a protocol for a factorial randomized controlled trial. Trials 2019; 20:736. [PMID: 31843024 PMCID: PMC6916111 DOI: 10.1186/s13063-019-3909-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 11/15/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Thiazide diuretics have demonstrated favorable blood pressure lowering efficacy, but the equivalent doses of their more common agents, chlorthalidone and hydrochlorothiazide, are still unclear. Further, concerns exist regarding adverse metabolic effects, which may be attenuated with the concomitant administration of a potassium-sparing diuretic, such as amiloride. This trial aims to investigate the efficacy of chlorthalidone and hydrochlorothiazide, in combination with amiloride at different doses, for initial management of patients with primary hypertension. METHODS/DESIGN This is a factorial (2 × 2) randomized double-blinded clinical trial comparing the association of a thiazide diuretic (chlorthalidone 25 mg/day or hydrochlorothiazide 50 mg/day) with a potassium-sparing diuretic (amiloride 10 mg/day or amiloride 20 mg/day) in patients with primary hypertension. The primary outcome will be the mean change from baseline in 24-h systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring. The secondary outcomes will be the mean change from baseline in daytime and nighttime systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring, mean change from baseline in systolic and diastolic blood pressure measured by office blood pressure, incidence of adverse events, variation of laboratory parameters, and proportion of patients who achieved blood pressure control. The follow-up will last 12 weeks. For a P alpha of 0.05, power of 80%, standard deviation of 9 mmHg, and absolute difference of 6 mmHg on systolic blood pressure on 24-h ambulatory blood pressure monitoring, it will be necessary to study a total of 76 patients. The sample size will be increased by 10% to compensate for losses, resulting in 84 patients being randomized. DISCUSSION Diuretics are pivotal drugs for the treatment of hypertension. Chlorthalidone and hydrochlorothiazide, in combination with amiloride in multiple doses, will be tested in terms of blood pressure lowering efficacy and safety. Since the intensity of blood pressure reduction is the major determinant of reduction in cardiovascular risk in hypertensive patients, this study will help to determine which combination of diuretics represents the most appropriate treatment for this population. TRIAL REGISTRATION ClinicalTrials.gov, NCT03928145. Registered on 25 April 2019. Last update on 29 April 2019.
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Affiliation(s)
- Vítor Magnus Martins
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| | - Lucas Helal
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Filipe Ferrari
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Leonardo Grabinski Bottino
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Sandra Costa Fuchs
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Flávio Danni Fuchs
- Graduate Program in Cardiology and Cardiovascular Sciences, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Division of Cardiology, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
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25
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Bohnert BN, Daiminger S, Wörn M, Sure F, Staudner T, Ilyaskin AV, Batbouta F, Janessa A, Schneider JC, Essigke D, Kanse S, Haerteis S, Korbmacher C, Artunc F. Urokinase-type plasminogen activator (uPA) is not essential for epithelial sodium channel (ENaC)-mediated sodium retention in experimental nephrotic syndrome. Acta Physiol (Oxf) 2019; 227:e13286. [PMID: 31006168 DOI: 10.1111/apha.13286] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 12/17/2022]
Abstract
AIM In nephrotic syndrome, aberrantly filtered plasminogen (plg) is converted to active plasmin by tubular urokinase-type plasminogen activator (uPA) and thought to lead to sodium retention by proteolytic activation of the epithelial sodium channel (ENaC). This concept predicts that uPA is an important factor for sodium retention and that inhibition of uPA might be protective in nephrotic syndrome. METHODS Activation of amiloride-sensitive currents by uPA and plg were studied in Xenopus laevis oocytes expressing murine ENaC. In doxorubicin-induced nephrotic mice, uPA was inhibited pharmacologically by amiloride and genetically by the use of uPA-deficient mice (uPA-/- ). RESULTS Experiments in Xenopus laevis oocytes expressing murine ENaC confirmed proteolytic ENaC activation by a combination of plg and uPA which stimulated amiloride-sensitive currents with concomitant cleavage of the ENaC γ-subunit at the cell surface. Treatment of nephrotic wild-type mice with amiloride inhibited urinary uPA activity, prevented urinary plasmin formation and sodium retention. In nephrotic mice lacking uPA (uPA-/- ), urinary plasmin formation from plg was suppressed and urinary uPA activity absent. However, in nephrotic uPA-/- mice, sodium retention was not reduced compared to nephrotic uPA+/+ mice. Amiloride prevented sodium retention in nephrotic uPA-/- mice which confirmed the critical role of ENaC in sodium retention. CONCLUSION uPA is responsible for the conversion of aberrantly filtered plasminogen to plasmin in the tubular lumen in vivo. However, uPA-dependent plasmin generation is not essential for ENaC-mediated sodium retention in experimental nephrotic syndrome.
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Affiliation(s)
- Bernhard N. Bohnert
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Sophie Daiminger
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Matthias Wörn
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Florian Sure
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Bayern Germany
| | - Tobias Staudner
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Bayern Germany
| | - Alexandr V. Ilyaskin
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Bayern Germany
| | - Firas Batbouta
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Andrea Janessa
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Jonas C. Schneider
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Daniel Essigke
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
| | - Sandip Kanse
- Institute of Basic Medical Sciences University of Oslo Oslo Norway
| | - Silke Haerteis
- Institute of Anatomy University of Regensburg Regensburg Germany
| | - Christoph Korbmacher
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Bayern Germany
| | - Ferruh Artunc
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
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26
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Abstract
Resistant hypertension is a common clinical entity, defined as suboptimal blood pressure response to multiple therapies after excluding medication nonadherence and secondary forms of hypertension. Patients with resistant hypertension generally share several comorbidities. Resistant hypertension is more common in individuals of African descent. Blood pressure should be optimized using multiple strategies, including lifestyle changes and single-pill combination therapies, with the aim of reducing cardiovascular events while reducing side effects from using antihypertensive therapy. A renin/aldosterone-based diagnostic and treatment approach will help tailor therapy. The use of mineralocorticoid receptor antagonists or amiloride as appropriate is favored.
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Affiliation(s)
- Fady Hannah-Shmouni
- Internal Medicine-Endocrinology, Hypertension and Metabolic Genetics, Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 Center Drive, MSC 1109, Bethesda, MD 20892, USA.
| | - Sriram Gubbi
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney diseases, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - J David Spence
- Stroke Prevention and Atherosclerosis Research Centre, Robarts Research Institute, Western University, 1400 Western Road, London, ON N6G 2V4, Canada
| | - Constantine A Stratakis
- Internal Medicine-Endocrinology, Hypertension and Metabolic Genetics, Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10 Center Drive, MSC 1109, Bethesda, MD 20892, USA
| | - Christian A Koch
- The University of Tennessee Health Science Center, 910 Madison Avenue, Memphis, TN 38163, USA
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27
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Buckley BJ, Majed H, Aboelela A, Minaei E, Jiang L, Fildes K, Cheung CY, Johnson D, Bachovchin D, Cook GM, Huang M, Ranson M, Kelso MJ. 6-Substituted amiloride derivatives as inhibitors of the urokinase-type plasminogen activator for use in metastatic disease. Bioorg Med Chem Lett 2019; 29:126753. [PMID: 31679971 DOI: 10.1016/j.bmcl.2019.126753] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 11/25/2022]
Abstract
The oral K+-sparing diuretic amiloride shows anti-cancer side-activities in multiple rodent models. These effects appear to arise, at least in part, through moderate inhibition of the urokinase-type plasminogen activator (uPA, Ki = 2.4 µM), a pro-metastatic trypsin-like serine protease that is upregulated in many aggressive solid malignancies. In applying the selective optimization of side-activity (SOSA) approach, a focused library of twenty two 6-substituted amiloride derivatives were prepared, with multiple examples displaying uPA inhibitory potencies in the nM range. X-ray co-crystal structures revealed that the potency increases relative to amiloride arise from increased occupancy of uPA's S1β subsite by the appended 6-substituents. Leading compounds were shown to have high selectivity over related trypsin-like serine proteases and no diuretic or anti-kaliuretic effects in rats. Compound 15 showed anti-metastatic effects in a xenografted mouse model of late-stage lung metastasis.
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Affiliation(s)
- Benjamin J Buckley
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Hiwa Majed
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Ashraf Aboelela
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Elahe Minaei
- Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia
| | - Longguang Jiang
- National Joint Biomdical Engineering Research Centre on Photodynamic Technologies, Fuzhou University, Fuzhou 350116, China
| | - Karen Fildes
- Illawarra Health and Medical Research Institute, NSW 2522, Australia; Graduate School of Medicine, University of Wollongong, NSW 2522, Australia
| | - Chen-Yi Cheung
- Department of Microbiology and Immunology, University of Otago, Otago 9016, New Zealand
| | - Darren Johnson
- Tri-institutional PhD Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, NY 10065, USA
| | - Daniel Bachovchin
- Tri-institutional PhD Program in Chemical Biology, Memorial Sloan Kettering Cancer Center, NY 10065, USA; Chemical Biology Program, Memorial Sloan Kettering Cancer Centre, NY 10065, USA
| | - Gregory M Cook
- Department of Microbiology and Immunology, University of Otago, Otago 9016, New Zealand
| | - Mingdong Huang
- National Joint Biomdical Engineering Research Centre on Photodynamic Technologies, Fuzhou University, Fuzhou 350116, China
| | - Marie Ranson
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia.
| | - Michael J Kelso
- School of Chemistry and Molecular Bioscience, University of Wollongong, NSW 2522, Australia; Illawarra Health and Medical Research Institute, NSW 2522, Australia; Molecular Horizons, University of Wollongong, NSW 2522, Australia.
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Gong MJ, Chang YY, Shao JJ, Li SF, Zhang YG, Chang HY. Antiviral effect of amiloride on replication of foot and mouth disease virus in cell culture. Microb Pathog 2019; 135:103638. [PMID: 31326561 PMCID: PMC7125800 DOI: 10.1016/j.micpath.2019.103638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 01/08/2023]
Abstract
Recently, amiloride was shown to potently suppress Coxsackievirus B3 (CVB3) replication. In the current study, we investigated whether amiloride could also exhibit antiviral activity against foot-and-mouth disease virus (FMDV), which belongs to the same family (Picornaviridae) as CVB3. We found that amiloride exerted antiviral activity in a dose-dependent manner against two strains of FMDV in IBRS-2 cells, with slight cytotoxicity at 1000 μM. Besides, amiloride did not inhibit the attachment and entry of FMDV in IBRS-2 cells, but prevented early viral replication. These data implied that amiloride could be a promising candidate for further research as a potential antiviral drug against FMDV infection.
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Affiliation(s)
- Mei-Jiao Gong
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China
| | - Yan-Yan Chang
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China
| | - Jun-Jun Shao
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China
| | - Shi-Fang Li
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China
| | - Yong-Guang Zhang
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China
| | - Hui-Yun Chang
- State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu, China.
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Izzo JL, Hong M, Hussain T, Osmond PJ. Long-term BP control and vascular health in patients with hyperaldosteronism treated with low-dose, amiloride-based therapy. J Clin Hypertens (Greenwich) 2019; 21:922-928. [PMID: 31169971 DOI: 10.1111/jch.13567] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/23/2019] [Accepted: 02/03/2019] [Indexed: 11/28/2022]
Abstract
Whether aldosterone itself contributes directly to macro- or microcirculatory disease in man or to adverse cardiovascular outcomes is not fully known. We report our long-term single-practice experience in 5 patients with chronic hyperaldosteronism (HA, including 3 with glucocorticoid remediable aldosteronism, GRA) treated with low-dose amiloride (a specific epithelial sodium channel [ENaC] blocker) 5-10 (mean 7) mg daily for 14-28 (mean 20) years. Except for 1 GRA diagnosed in infancy, all had severe resistant hypertension. In each case, BP was normal or near-normal within 1-4 weeks after starting amiloride and office BP's were well controlled for 20 years thereafter. Vascular studies and 24-hour ambulatory BP monitoring with pulse wave analysis (cardiac output, vascular resistance, augmentation index, and reflection magnitude) were assessed after a mean of 18 years as were regional pulse wave velocities, pulse stiffening ratio, ankle-brachial index, serum creatinine, estimated glomerular filtration rate, and spot urinary albumin:creatinine ratio. All indicators were completely normal in all patients after 18 years of amiloride, and none had a cardiovascular event during the 20-year mean follow-up. We conclude that long-term ENaC blockade can normalize BP and protect macro- and microvascular function in patients with HA. This suggests that (a) any vasculopathic effects of aldosterone are mediated via ENaC, not MR activation itself, and are fully preventable or reversible with ENaC blockade or (b) aldosterone may not play a major BP-independent role in human macro- and microcirculatory diseases. These and other widely divergent results in the literature underscore the need for additional studies regarding aldosterone, ENaC, and vascular disease.
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Affiliation(s)
- Joseph L Izzo
- Department of Medicine, Jacobs School of Medicine, University at Buffalo, Buffalo, New York.,Erie County Medical Center, Buffalo, New York
| | - Michael Hong
- Department of Medicine, Jacobs School of Medicine, University at Buffalo, Buffalo, New York.,Erie County Medical Center, Buffalo, New York
| | - Tanveer Hussain
- Department of Medicine, Jacobs School of Medicine, University at Buffalo, Buffalo, New York.,Erie County Medical Center, Buffalo, New York
| | - Peter J Osmond
- Department of Medicine, Jacobs School of Medicine, University at Buffalo, Buffalo, New York.,Erie County Medical Center, Buffalo, New York
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Zhang H, Peng C, Huang H, Lai Y, Hu C, Li F, Wang D. Effects of amiloride on physiological activity of stem cells of human lung cancer and possible mechanism. Biochem Biophys Res Commun 2018; 504:1-5. [PMID: 29958884 DOI: 10.1016/j.bbrc.2018.06.138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 06/25/2018] [Indexed: 02/07/2023]
Abstract
Lung cancer is a common malignant tumor, the cancer stem cells (CSCs) were regarded responsible for the development of cancer tissue. The effects of amiloride on lung cancer stem cells and the possible mechanism were not much investigated. In this study, human NCI-H1975 lung CSCs were selected by flow cytometry, and the effects of amiloride at different concentrations (0, 12.5, 25, 50, and 100 μmol/L) were evaluated on proliferation, migration, invasion and apoptosis of CSCs using cell counting kit-8 and Transwell migration assays as well as flow cytometry. Wstern blot analysis was performed to investigate the effect of amiloride on the level of proteins in uPA system, NF-kB pathway, and PI3K-AKT-mTOR pathway in CSCs. As a result, we found that amiloride inhibited proliferation, migration and invasion of lung CSCs, and promoted apoptosis. Further, we found that amiloride decreased levels of target proteins in the uPA system, as well as the NF-kB and PI3K-AKT-mTOR pathways. These results indicated that amiloride could inhibit proliferation, migration and invasion of lung CSCs, and promotes apoptosis, these effects may be related to decreased levels of proteins in the uPA system, the NF-kB pathway, and the PI3K-AKT-mTOR pathway.
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Affiliation(s)
- Hengshuo Zhang
- The First Clinical Medical College, Lanzhou University, Lanzhou 730000, China
| | - Caixia Peng
- The Second Clinical Medical College, Lanzhou University, Lanzhou 730000, China
| | - He Huang
- The First Clinical Medical College, Lanzhou University, Lanzhou 730000, China
| | - Yongxin Lai
- The Second Clinical Medical College, Lanzhou University, Lanzhou 730000, China
| | - Chenchen Hu
- The Second Clinical Medical College, Lanzhou University, Lanzhou 730000, China
| | - Fei Li
- Institute of Pathogen Biology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Degui Wang
- Department of Anatomy and Histology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
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Zhao M, Xu XQ, Meng XY, Liu B. The Heptahelical Domain of the Sweet Taste Receptor T1R2 Is a New Allosteric Binding Site for the Sweet Taste Modulator Amiloride That Modulates Sweet Taste in a Species-Dependent Manner. J Mol Neurosci 2018; 66:207-13. [PMID: 30120716 DOI: 10.1007/s12031-018-1156-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/06/2018] [Indexed: 10/28/2022]
Abstract
The activity of sweet taste receptor (heterodimeric T1R2 and T1R3) can be modulated by sweet regulators. The compound amiloride can inhibit the sweet sensitivity of the human sweet taste receptor. This study describes the species-dependent regulation of the response of sweet taste receptors by this sweet inhibitor. Amiloride inhibited the sweet taste response of humans and mice but not that of squirrel monkeys. Using human/squirrel monkey/mouse chimeric T1R2 and T1R3 receptors as well as the agonist perillartine (which can activate the single heptahelical domain of T1R2), we found that the heptahelical domain of T1R2 is the molecular determinant that mediates the species-dependent sensitivity to this sweet regulator. Compared to the sweet inhibitor lactisole (which acts on T1R3), amiloride has a different allosteric binding site on the sweet receptor, which is important new information for the design of novel sweet taste modulators that act on T1R2.
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Ahmad N, Ahmad R, Alam MA, Ahmad FJ, Amir M. Impact of ultrasonication techniques on the preparation of novel Amiloride-nanoemulsion used for intranasal delivery in the treatment of epilepsy. Artif Cells Nanomed Biotechnol 2018; 46:S192-S207. [PMID: 30032652 DOI: 10.1080/21691401.2018.1489826] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
AIM To develop a nanoemulsion-nanoformulation in order to enhance brain bioavailability for Amiloride (Amilo) via intranasal (i.n.) drug delivery in the brain. MATERIAL AND METHODS Oleic Acid, Tween-20 and Carbitol were selected as oil, surfactant and co-surfactant, respectively. For nanoemulsion preparation, an aqueous micro titration method followed by a high energy ultra-sonication method was used whereas three-factor three-level central composite design was employed to get the best formulation. The independent variables selected for the optimization were %oil, % Surfactant and co-surfactant (Smix) and sonication time (seconds). RESULTS Based on the constraints applied for independent and dependent variables, the optimized formulation was selected with 2.5% oil, 10% Smix and a sonication time of 45 s. The experimental values observed for dependent variables such as hydrodynamic diameter (nm), % transmittance and % cumulative drug release were found to be 89.36 ± 11.18 nm, 99.23 ± 0.84% and 80.36 ± 5.48%, respectively. Results showed; a spherical shape (transmission electron microscopy and scanning electron microscopy - assisted morphological characterization), polydispersity index (0.231 ± 0.018), zeta potential (-9.83 ± 0.12 mV), refractive index (1.38 ± 0.042), viscosity (41 ± 5 cp), pH (6.4 ± 0.18) and drug content of 98.28 ± 0.29%, for optimized Amiloride-loaded-Nanoemulsion (Amilo-NE). For bioavailability evaluation, ultra-performance liquid chromatography-mass spectroscopy based bioanalytical method was developed and validated for pharmacokinetics, biodistribution, brain-targeting efficiency (1992.67 ± 45.63%) and nose-to-brain transport (586.18 ± 11.63%) whereby an enhanced Amilo-brain bioavailability was observed as compared to intravenous administration (i.v.). Furthermore, Amilo-NE enhanced the treatment in seizure threshold i.e. both rodent models of epilepsy (increasing current electroshock and pentylenetetrazole) induced seizures in mice. CONCLUSION A significant role of Amilo-NE as observed after high targeting potential and efficiency of the formulation supports the easy brain targeting for Amilo-NE.
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Affiliation(s)
- Niyaz Ahmad
- a Department of Pharmaceutics, College of Clinical Pharmacy , Imam Abdulrahman Bin Faisal University , Dammam , Kingdom of Saudi Arabia
| | - Rizwan Ahmad
- b Department of Natural Products and Alternative Medicine, College of Clinical Pharmacy , Imam Abdulrahman Bin Faisal University , Dammam , Kingdom of Saudi Arabia
| | - Md Aftab Alam
- c Department of Pharmaceutics, School of Medical and Allied Sciences , Galgotias University , Gautam Budh Nagar , Greater Noida , India
| | - Farhan Jalees Ahmad
- d Nanomedicine Lab , Department of Pharmaceutics, School of Pharmaceutical Education and Research , Jamia Hamdard, Hamdard Nagar , New Delhi , India
| | - Mohd Amir
- b Department of Natural Products and Alternative Medicine, College of Clinical Pharmacy , Imam Abdulrahman Bin Faisal University , Dammam , Kingdom of Saudi Arabia
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Nagle L, Brown S, Krinos A, Ahearn GA. Ocean acidification: effects of pH on 45Ca uptake by lobster branchiostegites. J Comp Physiol B 2018; 188:739-747. [PMID: 30008138 DOI: 10.1007/s00360-018-1173-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/26/2018] [Accepted: 07/05/2018] [Indexed: 11/30/2022]
Abstract
Gill chambers of the Atlantic lobster, Homarus americanus, possess three structures that are involved with respiration and ion regulation: gill filaments, epipodites, and branchiostegites. This paper describes ion transport mechanisms present in the plasma membranes of branchiostegite epithelial cells and the effects of pH on the uptake of 45Ca by these processes. Partially purified membrane vesicles (PPMV) of branchiostegite cells were produced by a homogenization/centrifugation method that has previously been used to define ion transport processes in both crab and lobster gill tissues. In the present study, lobster branchiostegite PPMV 45Ca uptake was highest at pH 8.5 and lowest at pH values between 6.0 and 7.0 (p < 0.02). At pH 8.0, 45Ca uptake was a biphasic process consisting of a saturable process at low [Ca] and a linear process at higher [Ca]. At pH 6.0, 45Ca uptake was only a linear process and paralleled linear uptake at pH 8.0. A valinomycin/K+-induced membrane potential (PD, inside negative) doubled 45Ca uptake at pH 7.0 above that in the absence of a PD (p < 0.05). An induced PD at pH 8.0 did not significantly (p > 0.05) affect 45Ca uptake observed in the absence of a PD, but was threefold greater than uptake at pH 7.0 in the absence of a PD (p < 0.05). Amiloride (2 mM) did not affect 45Ca uptake at pH 8.0, but 2 mM amiloride + 100 µM verapamil reduced uptake by approximately 50%. In the presence of both 2 mM amiloride + 100 µM verapamil, 15 s 45Ca influx at pH 8.5 was a hyperbolic function of [Ca] (0.1-5 mM) (Km = 4.2 ± 0.3 mM; Jmax = 9792 ± 439 pmol/mg protein × 15 s). 45Ca influxes at pH 7.5 under the same conditions were also hyperbolic with Km = 8.3 ± 1.4 mM; Jmax = 10732 ± 1250 pmol/mg protein × 15 s. Km values were significantly different (p < 0.05), but Jmax values were not (p > 0.05). These results suggest that 45Ca uptake by lobster branchiostegites may have occurred by the combination of diffusion through a verapamil-inhibited calcium channel and carrier-mediated transport by amiloride-insensitive, electroneutral, 1Ca2+/2H+ antiporters. Decreased pH, as might occur during ocean acidification, did not appear to modify calcium diffusion through the channels, but protons acted as competitive inhibitors of calcium transport by carrier-mediated antiport. Decreased calcium uptake with continued ocean acidification may significantly affect calcification processes during periodic molting, potentially influencing mortality.
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Affiliation(s)
- Lilian Nagle
- Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA
| | - Skye Brown
- Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA
| | - Arianna Krinos
- Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA
| | - Gregory A Ahearn
- Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA.
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Abstract
The effects of diuretics on water and electrolyte metabolism are well-established, but less known to the clinician are their effects on bone and mineral metabolism, and in particular on that of calcium homeostasis. In general, and clinically most relevant, diuretics acting at the thick ascending limb of the loop of Henle cause loss of calcium into the urine, thus making them a useful tool in treating hypercalcemia. However the hypercalciuria caused by loop diuretics may lead to the development of urolithiasis and nephrocalcinosis, as well as secondary hyperparathyroidism and bone disease. On the other hand, thiazide diuretics that act more distally, increase tubular calcium reabsorption, thus providing protection against hypercalciuria, and with that may raise serum calcium, suppress PTH secretion and improve bone metabolism. Additional hypocalciuric effect may be observed with the use of potassium-sparing diuretics. This review will address the effects of diuretics on mineral metabolism in the kidney and consequently on systemic mineral and bone metabolism.
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Affiliation(s)
- Uri S Alon
- Division of Pediatric Nephrology, Children's Mercy Hospital Kansas City, 2401 Gillham Road, Kansas City, MO, USA, E-mail:
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Hołyńska-Iwan I, Dziembowska I, Smyk P, Lampka M, Olszewska-Słonina D. Capsaicin Used on Skin Influences Ion Transport Pathways: An in vitro Study. Skin Pharmacol Physiol 2017; 31:19-27. [PMID: 29131139 DOI: 10.1159/000481689] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/15/2017] [Indexed: 01/07/2023]
Abstract
Acute, adverse skin effects to capsaicin can be activated by inhibition of sodium transport not only in nociceptive neurons, but also in keratinocytes. The aim of the current study was to describe and compare immediate (15 s) and prolonged (30 min) effects of capsaicin on epidermal (not neural) sodium transport using a rabbit skin model. Skin fragments (n = 169) were incubated in 4 conditions: undisturbed ion transport (U; n = 48); inhibited sodium transport (INa; n = 34) with amiloride used as sodium transport blocker; long-term irritation by capsaicin with undisturbed ion transport (CAPSA-U; n = 43) and with inhibited sodium transport (CAPSA-INa; n = 35). After 30 min of incubation, a solution of capsaicin was applied directly to the skin fragments. The study demonstrated that sodium transport inhibition eliminated the effects of both immediate and prolonged capsaicin application. The results could be the basis for future research considering selective sodium transport inhibitors for human skin to reduce the side effects of capsaicin, related to activation of sodium channels in keratinocytes.
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Affiliation(s)
- Iga Hołyńska-Iwan
- Department of Pathobiochemistry and Clinical Chemistry, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Torun, Bydgoszcz, Poland
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Abstract
BACKGROUND To date, high-dose corticosteroids constitute the only established treatment of acute optic neuritis (ON); however, steroids cannot prevent the loss of retinal nerve fibers. New acute therapeutic drugs are therefore being sought for a reduction of ganglion cell death. METHODS Literature search comprising clinical studies on treatment of ON with immunomodulatory and neuroprotective drugs. RESULTS For the immunomodulatory drug simvastatin some evidence for long-term benefits was shown, particularly regarding visual evoked potentials. For the neuroprotective substance memantine a potential positive effect on retinal nerve fiber layer (RNFL) thickness was revealed. Likewise in one publication a reduction in loss of RNFL thickness could be demonstrated for erythropoietin and this drug is currently being extensively investigated in a phase III randomized controlled trial (RCT). The results of studies with phenytoin, amiloride and anti-leucine-rich repeat and immunoglobulin domain containing 1 protein (anti-LINGO-1) antibodies are awaiting publication. CONCLUSION According to the data from recent treatment trials, there is hope that neuronal loss in ON can be reduced with the help of immunomodulatory substances, such as simvastatin or neuroprotective agents, such as memantine and erythropoietin.
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Affiliation(s)
- F Beisse
- Universitäts-Augenklinik Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Deutschland.
| | - R Diem
- Neurologische Klinik, Universitätsklinikum Heidelberg, Heidelberg, Deutschland
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Larrazabal CS, Carretta MD, Hidalgo MA, Burgos RA. Amiloride interferes with platelet- activating factor-induced respiratory burst and MMP-9 release in bovine neutrophils independent of Na +/H + exchanger 1. Vet Immunol Immunopathol 2017; 191:68-73. [PMID: 28895869 DOI: 10.1016/j.vetimm.2017.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 08/10/2017] [Accepted: 08/22/2017] [Indexed: 01/15/2023]
Abstract
Cytoplasmic pH homeostasis is required for an appropriate response in polymorphonuclear neutrophils (PMNs). In these cells, chemotaxis and reactive oxygen species (ROS) production are reduced by the use of Na+/H+ exchanger (NHE-1) inhibitors, but these results are mainly obtained using amiloride, a non-selective NHE-1 inhibitor. In bovine PMNs, the role of NHE-1 in functional responses has not been confirmed yet. The aim of this study was to determine the role of NHE-1 using amiloride and zoniporide in pH regulation, ROS production, matrix metalloproteinase 9 (MMP-9) release and calcium flux in bovine PMNs induced by the platelet activation factor (PAF), additionally we evaluated the presence of NHE-1 and NHE-2 mRNA Our data show the presence only of NHE-1 but not NHE-2 in bovine PMNs. Amiloride or zoniporide inhibited the intracellular alkalization induced by PAF without affecting calcium flux. Amiloride diminished ROS production and MMP-9 release, while zoniporide enhanced ROS production without change the MMP-9 release induced by PAF. Our work led us to conclude that changes in intracellular pH induced by PAF are regulated by NHE-1 in bovine neutrophils, but the effects of amiloride on ROS production and MMP-9 release induced by PAF are not NHE-1 dependent.
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Affiliation(s)
- C S Larrazabal
- Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile
| | - M D Carretta
- Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile
| | - M A Hidalgo
- Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile
| | - R A Burgos
- Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile.
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Pontes G, Pereira MH, Barrozo RB. Salt controls feeding decisions in a blood-sucking insect. J Insect Physiol 2017; 98:93-100. [PMID: 27989677 DOI: 10.1016/j.jinsphys.2016.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/07/2016] [Accepted: 12/10/2016] [Indexed: 06/06/2023]
Abstract
Salts are necessary for maintaining homeostatic conditions within the body of all living organisms. Like with all essential nutrients, deficient or excessive ingestion of salts can result in adverse health effects. The taste system is a primary sensory modality that helps animals to make adequate feeding decisions in terms of salt consumption. In this work we show that sodium and potassium chloride salts modulate the feeding behavior of Rhodnius prolixus in a concentration-dependent manner. Feeding is only triggered by an optimal concentration of any of these salts (0.1-0.15M) and in presence of the phagostimulant ATP. Conversely, feeding solutions that do not contain salts or have a high-salt concentration (>0.3M) are not ingested by insects. Notably, we show that feeding decisions of insects cannot be explained as an osmotic effect, because they still feed over hyperosmotic solutions bearing the optimal salt concentration. Insects perceive optimal-salt, no-salt and high-salt solutions as different gustatory information, as revealed the electromyogram recordings of the cibarial pump. Moreover, because insects do a continuous gustatory monitoring of the incoming food during feeding, sudden changes beyond the optimal sodium concentration decrease and even inhibit feeding. The administration of amiloride, a sodium channel blocker, noticeably reduces the ingestion of the optimal sodium solution but not of the optimal potassium solution. Salt detection seems to occur at least through two salt receptors, one amiloride-sensitive and another amiloride-insensitive. Our results confirm the importance of the gustatory system in R. prolixus, showing the relevant role that salts play on their feeding decisions.
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Affiliation(s)
- Gina Pontes
- Grupo de Neuroetología de Insectos Vectores, Laboratorio Fisiología de Insectos, IBBEA, CONICET-UBA, DBBE, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, BA, Argentina
| | - Marcos H Pereira
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Romina B Barrozo
- Grupo de Neuroetología de Insectos Vectores, Laboratorio Fisiología de Insectos, IBBEA, CONICET-UBA, DBBE, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, BA, Argentina.
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Shah JV, Shah PA, Sanyal M, Shrivastav PS. Simultaneous quantification of amiloride and hydrochlorothiazide in human plasma by liquid chromatography-tandem mass spectrometry. J Pharm Anal 2017; 7:288-296. [PMID: 29404051 PMCID: PMC5790693 DOI: 10.1016/j.jpha.2017.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 03/06/2017] [Accepted: 03/23/2017] [Indexed: 11/17/2022] Open
Abstract
A selective, sensitive and precise assay based on solid phase extraction and liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed for the simultaneous determination of amiloride (AMI) and hydrochlorothiazide (HCTZ) in human plasma. Sample clean-up with 250 µL of plasma was done on Phenomenex Strata™-X extraction cartridges using their labeled internal standards (AMI-15N3 and HCTZ-13C,d2). Chromatography was performed on Hypersil Gold C18 (50 mm×3.0 mm, 5 µm) column using acetonitrile with 4.0 mM ammonium formate (pH 4.0, adjusted with 0.1% formic acid) (80:20, v/v) as the mobile phase. Detection was carried out on a triple quadrupole API 5500 mass spectrometer utilizing an electrospray ionization interface and operating in the positive ionization mode for AMI and negative ionization mode for HCTZ. Multiple reaction monitoring was used following the transitions at m/z 230.6/116.0, m/z 233.6/116.0, m/z 296.0/204.9 and m/z 299.0/205.9 for AMI, AMI-15N3, HCTZ and HCTZ-13C,d2, respectively. Calibration curves were linear (r2≥0.9997) over the concentration range of 0.050–50.0 and 0.50–500 ng/mL for AMI and HCTZ, respectively, with acceptable accuracy and precision. The signal-to-noise ratio at the limit of quantitation was ≥14 for both the analytes. The mean recovery of AMI and HCTZ from plasma was 89.0% and 98.7%, respectively. The IS-normalized matrix factors determined for matrix effect ranged from 0.971 to 1.024 for both the analytes. The validated LC–MS/MS method was successfully applied to a bioequivalence study using 5 mg AMI and 50 mg HCTZ fixed dose tablet formulation in 18 healthy Indian volunteers with good reproducibility.
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Affiliation(s)
- Jaivik V Shah
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, India
| | - Priyanka A Shah
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, India
| | - Mallika Sanyal
- Department of Chemistry, St. Xavier's College, Navrangpura, Ahmedabad 380009, India
| | - Pranav S Shrivastav
- Department of Chemistry, School of Sciences, Gujarat University, Ahmedabad 380009, India
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Fernandes LAB, Cestario EDES, Cosenso-Martin LN, Vilela-Martin JF, Yugar-Toledo JC, Fuchs FD. Chlorthalidone Plus Amiloride Reduces the Central Systolic Blood Pressure in Stage 1 Hypertension Patients. Cardiol Res 2017; 7:196-201. [PMID: 28197292 PMCID: PMC5295510 DOI: 10.14740/cr481w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2016] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Hypertension reduction strategies use blood pressure in the brachial artery as the primary endpoint. Individuals who achieve the target blood pressure reduction with antihypertensive treatment have residual cardiovascular risk attributed to the difference in pressure between the aorta and brachial artery. Antihypertensive treatment affects the intrinsic properties of the vascular wall and arterial stiffness markers and consequently the central pressure. Recent publications stress the importance of adequate control of the central compared to peripheral blood pressure. Related clinical implications suggest that individuals with normal peripheral but high central blood pressure should not receive antihypertensive drugs that act on the central pressure. Therefore, they are at greater cardiovascular risk. The aim of the study was to evaluate the effect of treatment with a thiazide diuretic versus losartan on the central blood pressure in stage 1 hypertensive patients. METHODS Twenty-five patients were randomized to the chlorthalidone 25 mg/amiloride 5 mg group (q.d.) and 25 patients received losartan 50 mg (b.i.d). The central systolic blood pressure (CSBP) and augmentation index (AIx 75) were assessed using applanation tonometry. The paired t-test was used to compare the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), CSBP and AIx 75 between the thiazide and losartan groups at baseline and after 6 months of treatment. RESULTS Significant reductions in CSBP (123.3 ± 14.2 vs. 113.4 ± 111.4, P = 0.0103) and AIx 75 (87.7 ± 9.6 vs. 83.8 ± 8.9, P = 0.0289) were observed after 6 months of drug treatment with chlorthalidone 25 mg/amiloride 5 mg (q.d.). The administration of losartan 50 mg (b.i.d) did not reduce the CSBP and there were insignificant changes in the AIx 75. CONCLUSIONS Six-month treatment of chlorthalidone/amiloride but not losartan reduces the CSBP and AIx 75 in adults with stage 1 hypertension.
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Affiliation(s)
| | | | - Luciana Neves Cosenso-Martin
- Endocrinology Division of the Internal Medicine Department, State Medical School of Sao Jose Rio Preto, SP (FAMERP), Brazil
| | - Jose Fernando Vilela-Martin
- Hypertension Clinic, Department of Internal Medicine, State Medical School of Sao Jose do Rio Preto (FAMERP), Sao Paulo, Brazil
| | - Juan Carlos Yugar-Toledo
- Hypertension Clinic, Department of Internal Medicine, State Medical School of Sao Jose do Rio Preto (FAMERP), Sao Paulo, Brazil
| | - Flavio Danni Fuchs
- Division of Cardiology, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
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Storozhuk M, Kondratskaya E, Nikolaenko L, Krishtal O. A modulatory role of ASICs on GABAergic synapses in rat hippocampal cell cultures. Mol Brain 2016; 9:90. [PMID: 27760555 PMCID: PMC5070181 DOI: 10.1186/s13041-016-0269-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/05/2016] [Indexed: 12/27/2022] Open
Abstract
Rapid acidification occurring during synaptic vesicle release can activate acid-sensing ion channels (ASICs) both on pre- and postsynaptic neurons. In the latter case, a fraction of postsynaptic current would be mediated by cation-selective acid-sensing ion channels. Additionally, in both cases, activation of acid-sensing ion channels could modulate synaptic strength by affecting transmitter release and/or sensitivity of postsynaptic receptors. To address potential involvement of acid-sensing ion channels in mediation/modulation of synaptic transmission at hippocampal GABAergic synapses, we studied effects of three structurally different blockers of acid-sensing ion channels on evoked postsynaptic currents using the patch-clamp technique. We found that GABAergic postsynaptic currents, recorded below their reversal potential as inward currents, are suppressed by all the employed blockers of acid-sensing ion channels. These currents were suppressed by ~ 20 % in the presence of a novel blocker 5b (1 μM) and by ~30 % in the presence of either amiloride (25 μM) or diminazene (20 μM). In the same cells the suppression of postsynaptic currents, recorded above their reversal potential as outward currents was statistically insignificant. These results imply that the effects of blockers in our experiments are at least partially postsynaptic. On the other hand, in the case of mediation of a fraction of postsynaptic current by acid-sensing ion channels, an increase of outward currents would be expected under our experimental conditions. Our analysis of a bicuculline-resistant fraction of postsynaptic currents also suggests that effects of the blockers are predominantly modulatory. In this work we present evidence for the first time that acid-sensing ion channels play a functional role at hippocampal GABAergic synapses. The suppressing effect of the blockers of acid-sensing ion channels on GABAergic transmission is due, at least partially, to a postsynaptic but (predominantly) modulatory mechanism. We hypothesize that the modulatory effect is due to functional crosstalk between ASICs and GABAA-receptors recently reported in isolated neurons, however, verification of this hypothesis is necessary.
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Affiliation(s)
- Maksim Storozhuk
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine. .,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine.
| | - Elena Kondratskaya
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine.,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine
| | | | - Oleg Krishtal
- Bogomoletz Institute of Physiology, Bogomoletz st. 4, Kiev, Ukraine.,State Key Laboratory of Molecular and Cellular Biology, Bogomoletz st. 4, Kiev, Ukraine
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Damian DJ, McNamee R, Carr M. Changes in selected metabolic parameters in patients over 65 receiving hydrochlorothiazide plus amiloride, atenolol or placebo in the MRC elderly trial. BMC Cardiovasc Disord 2016; 16:188. [PMID: 27716064 PMCID: PMC5050956 DOI: 10.1186/s12872-016-0368-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 09/28/2016] [Indexed: 11/25/2022] Open
Abstract
Background Treatment of hypertension reduces incidence of stroke, myocardial infarction and heart failure perhaps partly by controlling different metabolic parameters. There is limited information regarding the changes in potassium, sodium, weight, cholesterol and glucose levels in patients using anti-hypertensives. This study aimed to determine changes in potassium, sodium, glucose, cholesterol, weight, urea and urate levels in patients using anti-hypertensives. Furthermore, to describe these changes and differences between the atenolol, hydrochlorothiazide plus amiloride and placebo arms of the Medical Research Council (MRC) elderly randomised controlled trial. Methods Patients were randomly allocated to one of the three treatment arms. Measurements were taken at baseline, end of year one and end of year two in 4396 subjects. Linear Mixed Models (LMM) were used to determine the longitudinal profiles of sodium, potassium, weight, cholesterol, glucose, urea and urate. Estimates of changes within groups and difference between groups were obtained. Results Patients randomised to receive hydrochlorothiazide + amiloride experienced a significantly greater mean reduction in potassium, sodium and weight compared to placebo at end of year one - mean differences in change −0.18 mmol/L, (95 % CI: −0.21, −0.15); −1.45 mmol/L, (95 % CI: −1.62, −1.29) and −0.46 kgs (95 % CI: −0.73, −0.20) respectively, and greater increases in cholesterol, urea and urate - mean differences in change 0.16 mmol/L, (95 % CI: 0.10,0.22); 0.77 mmol/L, (95 % CI: 0.68, 0.87) and 53.10 μmol/L, (95 % CI: 49.35, 56.85) respectively. Changes were in the same direction but smaller in the atenololarm except for potassium and weight (increases). No group differences in glucose were found. Conclusion Results were in line with expectation except for lack of change in glucose in the hydrochlorothiazide + amiloride arms. Electronic supplementary material The online version of this article (doi:10.1186/s12872-016-0368-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Damian J Damian
- Community Health Department, Kilimanjaro Christian Medical Centre, P. O. Box 3010, Moshi, Tanzania. .,Biostatistics, Institute for Population Health, University of Manchester, Manchester, UK.
| | - Roseanne McNamee
- Biostatistics, Institute for Population Health, University of Manchester, Manchester, UK
| | - Matthew Carr
- Biostatistics, Institute for Population Health, University of Manchester, Manchester, UK
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Ergonul Z, Yang L, Palmer LG. Properties of acid-induced currents in mouse dorsal root ganglia neurons. Physiol Rep 2016; 4:4/9/e12795. [PMID: 27173673 PMCID: PMC4873640 DOI: 10.14814/phy2.12795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 04/15/2016] [Indexed: 11/29/2022] Open
Abstract
Acid‐sensing ion channels (ASICs) are cation channels that are activated by protons (H+). They are expressed in neurons throughout the nervous system and may play important roles in several neurologic disorders including inflammation, cerebral ischemia, seizures, neurodegeneration, anxiety, depression, and migraine. ASICs generally produce transient currents that desensitize in response to a decrease in extracellular pH. Under certain conditions, the inactivation of ASICs can be incomplete and allow them to produce sustained currents. Here, we characterize the properties of both transient and sustained acid‐induced currents in cultured mouse dorsal root ganglia (DRG) neurons. At pH levels between 7.3 and 7.1 they include “window currents” through ASICs. With stronger acid signals sustained currents are maintained in the absence of extracellular Na+ or the presence of the ASIC blockers amiloride and Psalmotoxin‐1(PcTx1). These sustained responses may have several different origins in these cells, including acid‐induced stimulation of inward Cl− currents, block of outward K+ currents, and augmentation of inward H+ currents, properties that distinguish these novel sustained currents from the well‐characterized transient currents.
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Affiliation(s)
- Zuhal Ergonul
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York Department of Pediatrics, NewYork-Presbyterian/Weill Cornell Medical Center, New York, New York
| | - Lei Yang
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York Department of Physiology, Harbin Medical University, Harbin, China
| | - Lawrence G Palmer
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York
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Giri SR, Bhoi B, Jain MR, Gatne MM. Cardioprotective role of peroxisome proliferator-activated receptor-γ agonist, rosiglitazone in a unique murine model of diabetic cardiopathy. Life Sci 2016; 162:1-13. [PMID: 27530514 DOI: 10.1016/j.lfs.2016.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 08/09/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
Abstract
AIMS Rosiglitazone (RSZ), a PPARγ agonist was potent efficacious insulin sensitizing blockbuster drug for treatment of Type 2 diabetes mellitus (T2DM) but the benefit of PPARγ activation in congestive heart failure (CHF) was controversial. The present work was planned to study the role of RSZ in diabetic cardiopathy. MAIN METHODS Zucker fa/fa rats, the genetic model of T2DM were subjected to constriction of suprarenal abdominal aorta so that they represent a combined model of diabetes and cardiopathy. The development cardiopathy was assessed biochemically (plasma BNP and aldosterone levels), using echocardiography and expression angiotensin II receptor type 1a gene in heart and Endothelin-1 gene in aorta. Rats were treated with RSZ and in combination with amiloride for four weeks and were assessed to evaluate the effect of RSZ or amiloride or its combination on antidiabetic activity, adverse or toxic effects and congestive heart failure status. KEY FINDINGS RSZ shows its anti-diabetic effect from 0.3mg/kg dose onwards and at 3mg/kg dose levels it caused beneficial effects (reduction of blood pressure) on cardiovascular system and at highest (30mg/kg) dose it starts showing adverse effects like body weight gain, edema, left ventricular hypertrophy. However, when highest dose of RSZ animals were treated with amiloride (ENaC inhibitor) at 2mg/kg the reversal of the adverse effects was evident, indicating the combination of RSZ and amiloride is beneficial in diabetic cardiopathy model. SIGNIFICANCE RSZ and amiloride combination appeared promising treatment in diabetic patients with cardiopathy without any side effect.
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Affiliation(s)
- Suresh R Giri
- Department of Pharmacology & Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej-Bavla N.H. No. 8A, Moraiya, Ahmedabad 382 213, Gujarat, India; Department of Pharmacology & Toxicology, Bombay Veterinary College, Parel, Mumbai 400012, India.
| | - Bibhuti Bhoi
- Department of Pharmacology & Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej-Bavla N.H. No. 8A, Moraiya, Ahmedabad 382 213, Gujarat, India
| | - Mukul R Jain
- Department of Pharmacology & Toxicology, Zydus Research Centre, Cadila Healthcare Limited, Sarkhej-Bavla N.H. No. 8A, Moraiya, Ahmedabad 382 213, Gujarat, India
| | - Madhumanjiri M Gatne
- Department of Pharmacology & Toxicology, Bombay Veterinary College, Parel, Mumbai 400012, India
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Abstract
In view of the toxicity of chromium (Cr3+) ions, it was explored the damaging effects that this ion could induce in cell membranes. The measurement of the effects induced by Cr3+ ions on electrophysiological parameters of short-circuit current and on the potential difference were investigated using the outer side (mucosal) and the inner side (serosal) of toad Pleurodema thaul skin. The results showed a decreased on electrophysiological parameters when it were administered concentrations of 33, 100 and 200 μM of Cr3+, the results also suggest that the administration of Cr3+ inhibits the ion transport in toad skin by the interaction of Cr3+ with lipid bilayers or protein constituents of membrane, and not by an inhibition of the active transport of ions across Na+ channels.
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Affiliation(s)
- Luis Guzman Jofre
- Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, University of Talca, Talca, Chile
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Pechère-Bertschi A, Herpin D, Lefebvre H. SFE/SFHTA/AFCE consensus on primary aldosteronism, part 7: Medical treatment of primary aldosteronism. Ann Endocrinol (Paris) 2016; 77:226-34. [PMID: 27315759 DOI: 10.1016/j.ando.2016.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 01/26/2016] [Indexed: 02/06/2023]
Abstract
Spironolactone, which is a potent mineralocorticoid receptor antagonist, represents the first line medical treatment of primary aldosteronism (PA). As spironolactone is also an antagonist of the androgen and progesterone receptor, it may present side effects, especially in male patients. In case of intolerance to spironolactone, amiloride may be used to control hypokaliemia and we suggest that eplerenone, which is a more selective but less powerful antagonist of the mineralocorticoid receptor, be used in case of intolerance to spironolactone and insufficient control of hypertension by amiloride. Specific calcic inhibitors and thiazide diuretics may be used as second or third line therapy. Medical treatment of bilateral forms of PA seem to be as efficient as surgical treatment of lateralized PA for the control of hypertension and the prevention of cardiovascular and renal morbidities. This allows to propose medical treatment of PA to patients with lateralized forms of PA who refuse surgery or to patients with PA who do not want to be explored by adrenal venous sampling to determine whether they have a bilateral or lateralized form.
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Fülöp T, Zsom L, Rodríguez B, Afshan S, Davidson JV, Szarvas T, Dixit MP, Tapolyai MB, Rosivall L. Clinical Utility of Potassium-Sparing Diuretics to Maintain Normal Serum Potassium in Peritoneal Dialysis Patients. Perit Dial Int 2016; 37:63-69. [PMID: 27282853 DOI: 10.3747/pdi.2016.00022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/01/2016] [Indexed: 11/15/2022] Open
Abstract
♦ BACKGROUND: Hypokalemia is a vexing problem in end-stage renal disease patients on peritoneal dialysis (PD), and oral potassium supplements (OPS) have limited palatability. Potassium-sparing diuretics (KSD) (spironolactone, amiloride) may be effective in these patients. ♦ METHODS: We performed a cross-sectional review of 75 current or past (vintage > 6 months) PD patients with regard to serum potassium (K+), OPS, and KSD utilization. We reviewed charts for multiple clinical and laboratory variables, including dialysis adequacy, residual renal function, nutritional status and co-existing medical therapy. ♦ RESULTS: The cohort was middle-aged with a mean age of 49.2 years (standard deviation [SD] = 14.7) and overweight with a body mass index of 29.5 (6.7) kg/m2. Of all the participants, 57.3% were female, 73.3% African-American, and 48% diabetic with an overall PD vintage of 28.2 (24.3) months at the time of enrollment. Weekly Kt/V was 2.12 (0.43), creatinine clearance was 73.5 (33.6) L/week/1.73 m2 with total daily exchange volume of 10.8 (2.7) L. Residual urine output (RUO) measured at 440 (494) mL (anuric 30.6%). Three-month averaged serum K+ measured at 4 (0.5) mmol/L with 36% of the participants receiving K+ supplements (median: 20 [0;20] mmol/day) and 41.3% KSD (spironolactone dose: 25 - 200 mg/day; amiloride dose: 5 - 10 mg/day). Serum K+ correlated positively with weekly Kt/V (r = 0.239; p = 0.039), PD vintage (r = 0.272; p = 0.018) but not with PD modality, daily exchange volume, RUO, or KSD use. However, KSD use was associated with decreased use of OPS (r = -0.646; p < 0.0001). ♦ CONCLUSIONS: Potassium-sparing diuretics were effective in this cohort of PD patients and decreased the need for OPS utilization.
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Affiliation(s)
- Tibor Fülöp
- Department of Medicine, Division of Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Lajos Zsom
- Department of Surgery, Division of Transplantation, University of Debrecen, Debrecen, Hungary
| | - Betzaida Rodríguez
- Department of Medicine, Division of Hospital Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Sabahat Afshan
- Department of Pediatrics, Division of Pediatric Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jamie V Davidson
- Department of Medicine, Division of Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Tibor Szarvas
- Department of Mathematics, Louisiana State University Shreveport, LA, USA
| | - Mehul P Dixit
- Department of Pediatrics, Division of Pediatric Nephrology, University of Mississippi Medical Center, Jackson, MS, USA
| | | | - László Rosivall
- Institute of Pathophysiology, Semmelweis University, Budapest, Hungary
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Hagiwara T, Yoshida S. Contribution of concentration-sensitive sodium channels to the absorption of alveolar fluid in mice. Respir Physiol Neurobiol 2016; 231:45-54. [PMID: 27259686 DOI: 10.1016/j.resp.2016.05.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/29/2016] [Accepted: 05/29/2016] [Indexed: 01/11/2023]
Abstract
The concentration-sensitive sodium channel (Nac) is activated by an increase in the extracellular sodium concentration. Although the expression of Nac in alveolar type II epithelial cells (AEC II) has been reported previously, the physiological role of Nac in the lung has not been established. We characterized Nac expression and examined amiloride-insensitive sodium transport mediated by Nac in mouse lung. Immunofluorescence studies revealed that Nac did not colocalize with either aquaporin 5 or cystic fibrosis transmembrane conductance regulator, but partially colocalized with the epithelial sodium channel γ-subunit. Immunoelectron microscopy studies showed that Nac localized at the basolateral membrane of pulmonary microvascular endothelial cells (PMVECs). Nac mRNA and protein were expressed in PMVECs isolated from the lungs of mice. Image analysis indicated that sodium influx into the alveolar wall was dependent on increases in extracellular sodium concentration. We conclude that Nac expressed in PMVECs and AEC II contributes to the reabsorption of sodium via an amiloride-insensitive pathway during alveolar fluid clearance.
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Vílchez MC, Morini M, Peñaranda DS, Gallego V, Asturiano JF, Pérez L. Sodium affects the sperm motility in the European eel. Comp Biochem Physiol A Mol Integr Physiol 2016; 198:51-8. [PMID: 27085371 DOI: 10.1016/j.cbpa.2016.04.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/04/2016] [Accepted: 04/09/2016] [Indexed: 11/17/2022]
Abstract
The role of seminal plasma sodium and activation media sodium on sperm motility was examined by selectively removing the element from these two media, in European eel sperm. Sperm size (sperm head area) was also measured using an ASMA (Automated Sperm Morphometry Analyses) system, in the different conditions. Intracellular sodium [Na(+)]i was quantitatively analyzed by first time in the spermatozoa from a marine fish species. Measurement of [Na(+)]i was done before and after motility activation, by Flow Cytometry, using CoroNa Green AM as a dye. Sperm motility activation induced an increase in [Na(+)]i, from 96.72mM in quiescent stage to 152.21mM post-activation in seawater. A significant decrease in sperm head area was observed post-activation in seawater. There was a notable reduction in sperm motility when sodium was removed from the seminal plasma, but not when it was removed from the activation media. Sodium removal was also linked to a significant reduction in sperm head area in comparison to the controls. Our results indicate that the presence of the ion Na(+) in the seminal plasma (or in the extender medium) is necessary for the preservation of sperm motility in European eel, probably because it plays a role in maintaining an appropriate sperm cell volume in the quiescent stage of the spermatozoa.
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Affiliation(s)
- M Carmen Vílchez
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain
| | - Marina Morini
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain
| | - David S Peñaranda
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain
| | - Víctor Gallego
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain
| | - Juan F Asturiano
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain
| | - Luz Pérez
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera, s/n., 46022 Valencia, Spain.
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Leng TD, Si HF, Li J, Yang T, Zhu M, Wang B, Simon RP, Xiong ZG. Amiloride Analogs as ASIC1a Inhibitors. CNS Neurosci Ther 2016; 22:468-76. [PMID: 26890278 DOI: 10.1111/cns.12524] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 12/30/2015] [Accepted: 01/16/2016] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND ASIC1a, the predominant acid-sensing ion channels (ASICs), is implicated in neurological disorders including stroke, traumatic spinal cord injury, and ALS. Potent ASIC1a inhibitors should have promising therapeutic potential for ASIC1a-related diseases. AIMS We examined the inhibitory effects of a number of amiloride analogs on ASIC1a currents, aimed at understanding the structure-activity relationship and identifying potent ASIC1a inhibitors for stroke intervention. METHODS Whole-cell patch-clamp techniques and a mouse model of middle cerebral artery occlusion (MCAO)-induced focal ischemia were used. Surflex-Dock was used to dock the analogs into the pocket with default parameters. RESULTS Amiloride and its analogs inhibit ASIC1a currents expressed in Chinese hamster ovary cells with a potency rank order of benzamil > phenamil > 5-(N,N-dimethyl)amiloride (DMA) > amiloride > 5-(N,N-hexamethylene)amiloride (HMA) ≥ 5-(N-methyl-N-isopropyl)amiloride (MIA) > 5-(N-ethyl-N-isopropyl)amiloride (EIPA). In addition, amiloride and its analogs inhibit ASIC currents in cortical neurons with the same potency rank order. In mice, benzamil and EIPA decreased MCAO-induced infarct volume. Similar to its effect on the ASIC current, benzamil showed a much higher potency than EIPA. CONCLUSION Addition of a benzyl group to the terminal guanidinyl group resulted in enhanced inhibitory activity on ASIC1a. On the other hand, the bulky groups added to the 5-amino residues slightly decreased the activity. Among the tested amiloride analogs, benzamil is the most potent ASIC1a inhibitor.
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Affiliation(s)
- Tian-Dong Leng
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
| | - Hong-Fang Si
- Anhui Medical University, School of Pharmacy, Hefei, Anhui, China
| | - Jun Li
- Anhui Medical University, School of Pharmacy, Hefei, Anhui, China
| | - Tao Yang
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
| | - Mengyuan Zhu
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Binghe Wang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Roger P Simon
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
| | - Zhi-Gang Xiong
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
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