1
|
Bhartiya P, Mumtaz S, Lim JS, Kaushik N, Lamichhane P, Nguyen LN, Jang JH, Yoon SH, Choi JJ, Kaushik NK, Choi EH. Pulsed 3.5 GHz high power microwaves irradiation on physiological solution and their biological evaluation on human cell lines. Sci Rep 2021; 11:8475. [PMID: 33875781 PMCID: PMC8055702 DOI: 10.1038/s41598-021-88078-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 04/07/2021] [Indexed: 02/02/2023] Open
Abstract
Microwave (MW) radiation is increasingly being used for several biological applications. Many investigations have focused on understanding the potential influences of pulsed MW irradiation on biological solutions. The current study aimed to investigate the effects of 3.5 GHz pulsed MW radiation-irradiated liquid solutions on the survival of human cancer and normal cells. Different physiological solutions such as phosphate buffer saline, deionized water, and Dulbecco's modified Eagle medium (DMEM) for cell culture growth were irradiated with pulsed MW radiation (45 shots with the energy of 1 mJ/shot). We then evaluated physiological effects such as cell viability, metabolic activity, mitochondrial membrane potential, cell cycle, and cell death in cells treated with MW-irradiated biological solutions. As MW irradiation with power density ~ 12 kW/cm2 mainly induces reactive nitrogen oxygen species in deionized water, it altered the cell cycle, membrane potential, and cell death rates in U373MG cells due to its high electric field ~ 11 kV/cm in water. Interestingly, MW-irradiated cell culture medium and phosphate-buffered saline did not alter the cellular viability and metabolic energy of cancer and normal cells without affecting the expression of genes responsible for cell death. Taken together, MW-irradiated water can alter cellular physiology noticeably, whereas irradiated media and buffered saline solutions induce negligible or irrelevant changes that do not affect cellular health.
Collapse
Affiliation(s)
- Pradeep Bhartiya
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Sohail Mumtaz
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Jun Sup Lim
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Neha Kaushik
- College of Engineering, Department of Biotechnology, University of Suwon, Hwaseong, 18323, Korea
| | - Pradeep Lamichhane
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Linh Nhat Nguyen
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Jung Hyun Jang
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Sang Ho Yoon
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Jin Joo Choi
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea
| | - Nagendra Kumar Kaushik
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea.
| | - Eun Ha Choi
- Plasma Bioscience Research Center/Applied Plasma Medicine Center, Department of Plasma Bio Display, Department of Electrical and Biological Physics, Kwangwoon University, Seoul, 01897, Korea.
| |
Collapse
|
2
|
Results, meta-analysis and a first evaluation of U NOxR, the urinary nitrate-to-nitrite molar ratio, as a measure of nitrite reabsorption in experimental and clinical settings. Amino Acids 2018; 50:799-821. [PMID: 29728915 DOI: 10.1007/s00726-018-2573-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 04/19/2018] [Indexed: 02/07/2023]
Abstract
We recently found that renal carbonic anhydrase (CA) is involved in the reabsorption of inorganic nitrite (NO2-), an abundant reservoir of nitric oxide (NO) in tissues and cells. Impaired NO synthesis in the endothelium and decreased NO bioavailability in the circulation are considered major contributors to the development and progression of renal and cardiovascular diseases in different conditions including diabetes. Isolated human and bovine erythrocytic CAII and CAIV can convert nitrite to nitrous acid (HONO) and its anhydride N2O3 which, in the presence of thiols (RSH), are further converted to S-nitrosothiols (RSNO) and NO. Thus, CA may be responsible both for the homeostasis of nitrite and for its bioactivation to RSNO/NO. We hypothesized that enhanced excretion of nitrite in the urine may contribute to NO-related dysfunctions in the renal and cardiovascular systems, and proposed the urinary nitrate-to-nitrite molar ratio, i.e., UNOxR, as a measure of renal CA-dependent excretion of nitrite. Based on results from clinical and experimental animal studies, here, we report on a first evaluation of UNOxR. We determined UNOxR values in preterm neonates, healthy children, and adults, in children suffering from type 1 diabetes mellitus (T1DM) or Duchenne muscular dystrophy (DMD), in elderly subjects suffering from chronic rheumatic diseases, type 2 diabetes mellitus (T2DM), coronary artery disease (CAD), or peripheral arterial occlusive disease (PAOD). We also determined UNOxR values in healthy young men who ingested isosorbide dinitrate (ISDN), pentaerythrityl tetranitrate (PETN), or inorganic nitrate. In addition, we tested the utility of UNOxR in two animal models, i.e., the LEW.1AR1-iddm rat, an animal model of human T1DM, and the APOE*3-Leiden.CETP mice, a model of human dyslipidemia. Mean UNOxR values were lower in adult patients with rheumatic diseases (187) and in T2DM patients of the DALI study (74) as compared to healthy elderly adults (660) and healthy young men (1500). The intra- and inter-variabilities of UNOxR were of the order of 50% in young and elderly healthy subjects. UNOxR values were lower in black compared to white boys (314 vs. 483, P = 0.007), which is in line with reported lower NO bioavailability in black ethnicity. Mean UNOxR values were lower in DMD (424) compared to healthy (730) children, but they were higher in T1DM children (1192). ISDN (3 × 30 mg) decreased stronger UNOxR compared to PETN (3 × 80 mg) after 1 day (P = 0.046) and after 5 days (P = 0.0016) of oral administration of therapeutically equivalent doses. In healthy young men who ingested NaNO3 (0.1 mmol/kg/d), UNOxR was higher than in those who ingested the same dose of NaCl (1709 vs. 369). In LEW.1AR1-iddm rats, mean UNOxR values were lower than in healthy rats (198 vs. 308) and comparable to those in APOE*3-Leiden.CETP mice (151).
Collapse
|
3
|
Tsikas D, Schwedhelm KS, Surdacki A, Giustarini D, Rossi R, Kukoc-Modun L, Kedia G, Ückert S. S-Nitroso- N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)-Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H 2S and GSH suppliers and as antioxidants: Results and overview. J Pharm Anal 2017; 8:1-9. [PMID: 29568662 PMCID: PMC5859134 DOI: 10.1016/j.jpha.2017.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/05/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022] Open
Abstract
S-Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosyl cation (NO+) and a thiolate (RS−), the base of the corresponding acids RSH. The smallest S-nitrosothiol is HSNO and derives from hydrogen sulfide (HSH, H2S). The most common physiological S-nitrosothiols are derived from the amino acid L-cysteine (CysSH). Thus, the simplest S-nitrosothiol is S-nitroso-L-cysteine (CysSNO). CysSNO is a spontaneous potent donor of nitric oxide (NO) which activates soluble guanylyl cyclase to form cyclic guanosine monophosphate (cGMP). This activation is associated with multiple biological actions that include relaxation of smooth muscle cells and inhibition of platelet aggregation. Like NO, CysSNO is a short-lived species and occurs physiologically at concentrations around 1 nM in human blood. CysSNO can be formed from CysSH and higher oxides of NO including nitrous acid (HONO) and its anhydride (N2O3). The most characteristic feature of RSNO is the S-transnitrosation reaction by which the NO+ group is reversibly transferred to another thiolate. By this way numerous RSNO can be formed such as the low-molecular-mass S-nitroso-N-acetyl-L-cysteine (SNAC) and S-nitroso-glutathione (GSNO), and the high-molecular-mass S-nitrosol-L-cysteine hemoglobin (HbCysSNO) present in erythrocytes and S-nitrosol-L-cysteine albumin (AlbCysSNO) present in plasma at concentrations of the order of 200 nM. All above mentioned RSNO exert NO-related biological activity, but they must be administered intravenously. This important drawback can be overcome by lipophilic charge-free RSNO. Thus, we prepared the ethyl ester of SNAC, the S-nitroso-N-acetyl-L-cysteine ethyl ester (SNACET), from synthetic N-acetyl-L-cysteine ethyl ester (NACET). Both NACET and SNACET have improved pharmacological features over N-acetyl-L-cysteine (NAC) and S-nitroso-N-acetyl-L-cysteine (SNAC), respectively, including higher oral bioavailability. SNACET exerts NO-related activities which can be utilized in the urogenital tract and in the cardiovascular system. NACET, with high oral bioavailability, is a strong antioxidant and abundant precursor of GSH, unlike its free acid N-acetyl-L-cysteine (NAC). Here, we review the chemical and pharmacological properties of SNACET and NACET as well as their analytical chemistry. We also report new results from the ingestion of S-[15N]nitroso-N-acetyl-L-cysteine ethyl ester (S15NACET) demonstrating the favorable pharmacological profile of SNACET.
Collapse
Affiliation(s)
- Dimitrios Tsikas
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, 30623 Hannover, Germany
| | - Kathrin S Schwedhelm
- Institute of Toxicology, Core Unit Proteomics, Hannover Medical School, 30623 Hannover, Germany
| | - Andrzej Surdacki
- Second Department of Cardiology, Jagiellonian University Medical College, Cracow, Poland
| | - Daniela Giustarini
- Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, Italy
| | - Ranieri Rossi
- Department of Life Sciences, Laboratory of Pharmacology and Toxicology, University of Siena, 53100 Siena, Italy
| | - Lea Kukoc-Modun
- Department of Analytical Chemistry, Faculty of Chemistry and Technology, University of Split, 21000 Split, Croatia
| | - George Kedia
- Department of Urology and Urological Oncology, Hannover Medical School, 30623 Hannover, Germany
| | - Stefan Ückert
- Department of Urology and Urological Oncology, Hannover Medical School, 30623 Hannover, Germany
| |
Collapse
|
4
|
Zhu Q, Shao XM, Kao L, Azimov R, Weinstein AM, Newman D, Liu W, Kurtz I. Missense mutation T485S alters NBCe1-A electrogenicity causing proximal renal tubular acidosis. Am J Physiol Cell Physiol 2013; 305:C392-405. [PMID: 23636456 DOI: 10.1152/ajpcell.00044.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mutations in SLC4A4, the gene encoding the electrogenic Na(+)-HCO3(-) cotransporter NBCe1, cause severe proximal renal tubular acidosis (pRTA), growth retardation, decreased IQ, and eye and teeth abnormalities. Among the known NBCe1 mutations, the disease-causing mechanism of the T485S (NBCe1-A numbering) mutation is intriguing because the substituted amino acid, serine, is structurally and chemically similar to threonine. In this study, we performed intracellular pH and whole cell patch-clamp measurements to investigate the base transport and electrogenic properties of NBCe1-A-T485S in mammalian HEK 293 cells. Our results demonstrated that Ser substitution of Thr485 decreased base transport by ~50%, and importantly, converted NBCe1-A from an electrogenic to an electroneutral transporter. Aqueous accessibility analysis using sulfhydryl reactive reagents indicated that Thr485 likely resides in an NBCe1-A ion interaction site. This critical location is also supported by the finding that G486R (a pRTA causing mutation) alters the position of Thr485 in NBCe1-A thereby impairing its transport function. By using NO3(-) as a surrogate ion for CO3(2-), our result indicated that NBCe1-A mediates electrogenic Na(+)-CO3(2-) cotransport when functioning with a 1:2 charge transport stoichiometry. In contrast, electroneutral NBCe1-T485S is unable to transport NO3(-), compatible with the hypothesis that it mediates Na(+)-HCO3(-) cotransport. In patients, NBCe1-A-T485S is predicted to transport Na(+)-HCO3(-) in the reverse direction from blood into proximal tubule cells thereby impairing transepithelial HCO3(-) absorption, possibly representing a new pathogenic mechanism for generating human pRTA.
Collapse
Affiliation(s)
- Quansheng Zhu
- Division of Nephrology, Department of Medicine, University of California, Los Angeles, CA 90095-1689, USA.
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Chobanyan-Jürgens K, Schwarz A, Böhmer A, Beckmann B, Gutzki FM, Michaelsen JT, Stichtenoth DO, Tsikas D. Renal carbonic anhydrases are involved in the reabsorption of endogenous nitrite. Nitric Oxide 2012; 26:126-31. [PMID: 22290016 DOI: 10.1016/j.niox.2012.01.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/05/2012] [Accepted: 01/12/2012] [Indexed: 01/28/2023]
Abstract
Nitrite (ONO(-)) exerts nitric oxide (NO)-related biological actions and its concentration in the circulation may be of particular importance. Nitrite is excreted in the urine. Hence, the kidney may play an important role in nitrite/NO homeostasis in the vasculature. We investigated a possible involvement of renal carbonic anhydrases (CAs) in endogenous nitrite reabsorption in the proximal tubule. The potent CA inhibitor acetazolamide was administered orally to six healthy volunteers (5 mg/kg) and nitrite was measured in spot urine samples before and after administration. Acetazolamide increased abruptly nitrite excretion in the urine, strongly suggesting that renal CAs are involved in nitrite reabsorption in healthy humans. Additional in vitro experiments support our hypothesis that nitrite reacts with CO(2), analogous to the reaction of peroxynitrite (ONOO(-)) with CO(2), to form acid-labile nitrito carbonate [ONOC(O)O(-)]. We assume that this reaction is catalyzed by CAs and that nitrito carbonate represents the nitrite form that is actively transported into the kidney. The significance of nitrite reabsorption in the kidney and the underlying mechanisms, notably a direct involvement of CAs in the reaction between nitrite and CO(2), remain to be elucidated.
Collapse
Affiliation(s)
- Kristine Chobanyan-Jürgens
- Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | | | | | | | | | | | | | | |
Collapse
|
6
|
|
7
|
Hayashi H, Suruga K, Yamashita Y. Regulation of intestinal Cl−/HCO3− exchanger SLC26A3 by intracellular pH. Am J Physiol Cell Physiol 2009; 296:C1279-90. [DOI: 10.1152/ajpcell.00638.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
SLC26A3, a Cl−/HCO3− exchanger, is highly expressed in intestinal epithelial cells, and its mutations cause congenital chloride diarrhea. This suggests that SLC26A3 plays a key role in NaCl absorption in the intestine. Electroneutral NaCl absorption in the intestine is mediated by functional coupling of the Na+/H+ exchanger and Cl−/HCO3− exchanger. It is proposed that the coupling of these exchangers may occur as a result of indirect linkage by changes of intracellular pH (pHi). We therefore investigated whether SLC26A3 is regulated by pHi. We generated a hemagglutinin epitope-tagged human SLC26A3 construct and expressed it in Chinese hamster ovary cells. Transport activities were measured with a fluorescent chloride-sensitive dye dihydro-6-methoxy- N-ethylquinolinium iodide (diH-MEQ). pHi was clamped at a range of values from 6.0 to 7.4. We monitored the transport activity of SLC26A3 by reverse mode of Cl−/HCO3− and Cl−/NO3− exchange. None of these exchange modes induced membrane potential changes. At constant external pH 7.4, Cl−/HCO3− exchange was steeply inhibited with pHi decrease between 7.3 and 6.8 as opposed to thermodynamic prediction. In contrast, however, Cl−/NO3− exchange was essentially insensitive to pHi within physiological ranges. We also characterized the pHi dependency of COOH-terminal truncation mutants. Removal of the entire COOH-terminal resulted in decrease of the transport activity but did not noticeably affect pHi sensitivity. These results suggest that Cl−/HCO3− exchange mode of human SLC26A3 is controlled by a pH-sensitive intracellular modifier site, which is likely in the transmembrane domain. These observations raise the possibility that SLC26A3 activity may be regulated via Na+/H+ exchanger 3 (NHE3) through the alteration of pHi under physiological conditions.
Collapse
|
8
|
Jabłoński J, Jabłońska E, Iwanowska J, Marcińczyk M, Moniuszko-Jakoniuk J. The Influence of Human Neutrophils on N-nitrosodimethylamine (NDMA) Synthesis. Immunopharmacol Immunotoxicol 2008; 28:93-102. [PMID: 16684670 DOI: 10.1080/08923970600625892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
N-nitrozodimethyloamine (NDMA) is a carcinogenic compound that can be formed in vivo. NDMA is synthesized from precursors-amines and nitrosating agents. Nitrosating agents are formed through the reaction of oxide, reactive oxygen species and nitric oxide (NO). Human neutrophils (PMN) are an important source of the most reactive oxygen species as well as of the nitric oxide. The increase in oxygen metabolism of PMN can lead to the increase nitrosating agent and nitroso-forms. Inflammatory process is associated with locally decreased pH that may favor nitrosation reaction. In the present study, we estimated the NDMA synthesis by LPS-stimulated PMN in the presence of the iNOS inhibitor--N-nitro-L-arginine methyl ester (L-NAME). In the nitrosation reaction dimethylamine (DMA) was used as substrat. The viability of the cells was measured by cytometric method. NDMA concentrations the culture media was measured by GCMS method. NO production was estimated by Griess's method. Expression of iNOS was determined by western blotting. Results obtained showed that DMA nitrosation is most effective in pH between 3-4.5. Nonstimulated PMN produced lower concentrations of NO than LPS-stimulated cells (1.27 microg/cm3 and 1.57 microg/cm3, respectively). In the culture of nonstimulated PMN supplemented with DMA, there was NDMA (mean--0.99 ng/cm3). In the culture of LPS-stimulated PMN in the presence of DMA, the concentration of NDMA was higher than in the culture of nonstimulated PMN (median--1.45 ng/cm3). In the supernatants of cells incubated without DMA and with DMA, LPS and L-NAME, no NDMA was detected. These results indicate that PMN can be one of sources of nitrosating agents and can play a role in endogenous NDMA synthesis. Stimulation of PMN can lead to the increase of NDMA concentration following the increase of NO production. Different pathological conditions associated with PMN activation as well as the decreased pH may favor endogenous NDMA synthesis.
Collapse
Affiliation(s)
- Jakub Jabłoński
- Department of Toxicology, Medical University of Białystok, Poland.
| | | | | | | | | |
Collapse
|
9
|
Santacroce PV, Okunola OA, Zavalij PY, Davis JT. A transmembrane anion transporter selective for nitrate over chloride. Chem Commun (Camb) 2006:3246-8. [PMID: 17028758 DOI: 10.1039/b607221f] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The C3-symmetric triamide selectively transports NO3- anions across lipid vesicles: this H+-NO3- co-transporter alters the pH inside of liposomes experiencing a NO3-/Cl- gradient.
Collapse
Affiliation(s)
- Paul V Santacroce
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | | | | | | |
Collapse
|
10
|
Kucera I. Energy coupling to nitrate uptake into the denitrifying cells of Paracoccus denitrificans. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1709:113-8. [PMID: 16112075 DOI: 10.1016/j.bbabio.2005.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 06/29/2005] [Accepted: 07/25/2005] [Indexed: 10/25/2022]
Abstract
This study deals with the effects of the agents that dissipate the individual components of the proton motive force (short-chain fatty acids, nigericin, and valinomycin) upon the methyl viologen-coupled nitrate reductase activity in intact cells. Substitution of butyrate or acetate for chloride in Tris-buffered assay media resulted in a marked inhibition at pH 7. In a Tris--chloride buffer of neutral pH, the reaction was almost fully inhibitable by nigericin. Alkalinisation increased the IC(50) value for nigericin and decreased the maximal inhibition attained. Both types of inhibitions could be reversed by the permeabilisation of cells or by the addition of nitrite, and that caused by nigericin disappeared at high extracellular concentrations of potassium. These data indicate that nitrate transport step relies heavily on the pH gradient at neutral pH. Since the affinity of cells for nitrate was strongly diminished by imposing an inside-positive potassium (or lithium) diffusion potential at alkaline external pH, a potential dependent step may be of significance in the transporter cycle under these conditions. Experiments with sodium-depleted media provided no hints for Na(+) as a possible H(+) substitute.
Collapse
Affiliation(s)
- Igor Kucera
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, CZ-61137 Brno, Czech Republic.
| |
Collapse
|
11
|
Okubo M, Yamada K, Hosoyamada M, Shibasaki T, Endou H. Cadmium transport by human Nramp 2 expressed in Xenopus laevis oocytes. Toxicol Appl Pharmacol 2003; 187:162-7. [PMID: 12662899 DOI: 10.1016/s0041-008x(02)00078-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Using the Xenopus oocyte expression system, human Nramp2, a human intestinal iron transporter, was shown to work as a cadmium transporter. An 1824-bp human Nramp2 cDNA was constructed by PCR cloning from reverse transcription products of human kidney mRNA. When the pH of the extracellular solution was 6.0, human Nramp2 transported (109)Cd(2+). Substitution of external Cl(-) with NO3- had no effect on human Nramp2-dependent cadmium uptake. The concentration-dependent Cd(2+) transport of human Nramp2 indicated Michaelis-Menten type transport with an average K(m) value of 1.04 +/- 0.13 microM and an average V(max) of 14.7 +/- 1.9 pmol/oocyte/h (n = 3). Cd(2+) transport via human Nramp2 was inhibited significantly by Cd(2+), Fe(2+), Pb(2+), Mn(2+), Cu(2+), and Ni(2+), while it was not inhibited by Hg(2+) and Zn(2+). Transport of 0.1 microM Cd(2+) by human Nramp2 was inhibited by metallothionein (IC50 = 0.14 microM). Therefore, human Nramp2 is suggested to function as a pH-dependent cadmium absorption transporter on the luminal membrane of human intestinal cells.
Collapse
Affiliation(s)
- Masato Okubo
- Department of Therapeutics, Kyoritsu College of Pharmacy, Shibakoen 1-5-30, Minato-ku, Tokyo, 105-8512, Japan
| | | | | | | | | |
Collapse
|
12
|
Yang F, Comtois AS, Fang L, Hartman NG, Blaise G. Nitric oxide-derived nitrate anion contributes to endotoxic shock and multiple organ injury/dysfunction. Crit Care Med 2002; 30:650-7. [PMID: 11990929 DOI: 10.1097/00003246-200203000-00026] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Because nitrate represents the major end-product of nitric oxide in vivo and can affect enzyme activity, cell electrophysiological functions, and cell membrane integrity, we hypothesized that overaccumulated nitric oxide-derived nitrate anion in tissues or organs in vivo may contribute to endotoxic shock and multiple organ injury/dysfunction during endotoxemia. DESIGN Prospective, experimental animal study. SETTING Laboratory at a university hospital. SUBJECTS Sprague-Dawley rats. INTERVENTIONS Rats were injected intraperitoneally with 5, 10, or 20 mg/kg lipopolysaccharide or saline and were studied in groups at 0, 6, 12, and 24 hrs. MEASUREMENTS AND MAIN RESULTS Significant differences were seen between nitrate concentrations in the heart, lung, kidney, liver, brain, aorta, diaphragm, spleen, thymus, testis or ovary, hind limb muscle, intestine, adipose tissue, bone, bladder, urine and plasma, which imply a nitrate gradient between intracellular and extracellular compartments. Lipopolysaccharide significantly increased nitrate concentration at 12 hrs in most tissues and organs, except in the brain, adipose tissue, and muscle. It increased more in plasma than in tissues. The lipopolysaccharide dose-dependent nitrate concentration was observed only in the aorta and lungs. The nitrate concentration change was paralleled by the systemic inflammatory response syndrome, as indicated by alterations of myeloperoxidase activity and by impaired histologic and cellular membrane integrity in tissues and organs. Mean arterial pressure was negatively correlated with nitrate concentration modifications in the aorta during 24 hrs of endotoxemia. CONCLUSIONS These results collectively indicate that overaccumulated nitric oxide-derived nitrate anion in tissues or organs in vivo contributes to endotoxic shock and multiple organ injury/dysfunction during endotoxemia.
Collapse
Affiliation(s)
- Fan Yang
- Laboratory of Anesthesia, Centre hospitalier de l'Université de Montréal-Hôpital Notre-Dame and Université de Montréal, Québec, Canada.
| | | | | | | | | |
Collapse
|
13
|
Oldreive C, Rice-Evans C. The mechanisms for nitration and nitrotyrosine formation in vitro and in vivo: impact of diet. Free Radic Res 2001; 35:215-31. [PMID: 11697121 DOI: 10.1080/10715760100300761] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The detection of 3-nitro-L-tyrosine residues associated with many disease states, including gastric cancer, has implicated a role for peroxynitrite in vivo, and thus endogenously produced nitric oxide and superoxide. Additionally, dietary nitrate has been suggested to be involved in the pathogenesis of gastric cancer through a mechanism involving reduction to nitrite and subsequent formation of potentially mutagenic nitroso-compounds. Studies have now demonstrated that a multitude of reactive nitrogen species other than peroxynitrite are capable of producing nitrotyrosine. Thus, we have reviewed the evidence that dietary nitrate, amongst other reactive nitrogen species, may contribute to the body burden of nitrotyrosine.
Collapse
Affiliation(s)
- C Oldreive
- Wolfson Centre for Age-Related Diseases, Guy's, King's and St. Thomas School of Biomedical Sciences, King's College London, London SE1 9RT
| | | |
Collapse
|
14
|
Zhou JJ, Trueman LJ, Boorer KJ, Theodoulou FL, Forde BG, Miller AJ. A high affinity fungal nitrate carrier with two transport mechanisms. J Biol Chem 2000; 275:39894-9. [PMID: 10984478 DOI: 10.1074/jbc.m004610200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have expressed the CRNA high affinity nitrate transporter from Emericella (Aspergillus) nidulans in Xenopus oocytes and used electrophysiology to study its properties. This method was used because there are no convenient radiolabeled substrates for the transporter. Oocytes injected with crnA mRNA showed nitrate-, nitrite-, and chlorite-dependent currents. Although the gene was originally identified by chlorate selection there was no evidence for transport of this anion. The gene selection is explained by the high affinity of the transporter for chlorite, and the fact that this ion contaminates solutions of chlorate. The pH-dependence of the anion-elicited currents was consistent with H(+)-coupled mechanism of transport. At any given voltage, currents showed hyperbolic kinetics with respect to extracellular H(+), and these data could be fitted with a Michaelis-Menten relationship. But this equation did not adequately describe transport of the anion substrates. At higher concentrations of the anion substrates and more negative membrane voltages, the currents were decreased, but this effect was independent of changes in external pH. These more complicated kinetics could be fit by an equation containing two Michaelis-Menten terms. The substrate inhibition of the currents could be explained by a transport reaction cycle that included two routes for the transfer of nitrate across the membrane, one on the empty carrier and the other proton coupled. The model predicts that the substrate inhibition of transporter current depends on the cytosolic nitrate concentration. This is the first time a high affinity nitrate transport activity has been characterized in a heterologous system and the measurements show how the properties of the CRNA transporter are modified by changes in the membrane potential, external pH, and nitrate concentration. The physiological significance of these observations is discussed.
Collapse
Affiliation(s)
- J J Zhou
- Biochemistry and Physiology Department, Integrated Approach to Crop Research (IACR)-Rothamsted, Harpenden, Herts, AL5 2JQ, United Kingdom
| | | | | | | | | | | |
Collapse
|
15
|
Harvey BH. Acid-dependent dismutation of nitrogen oxides may be a critical source of nitric oxide in human macrophages. Med Hypotheses 2000; 54:829-31. [PMID: 10859695 DOI: 10.1054/mehy.1999.0960] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The cytotoxic activity of the macrophage relies greatly on the secretion of a number of reactant intermediates, including superoxide (O(2)(-)), hydroxyl radical (OH(-)) and nitric oxide (NO). The latter, synthesized via cytokine-mediated induction of inducible NO-synthase (iNOS), is readily observed in murine macrophages. However, a poorly reproducible or minimal response to cytokine-stimulation in the human macrophage has questioned the presence or significance of this important pathway in man. Nevertheless, iNOS is present in other human phagocytic cells, e.g. neutrophils, while the NO metabolites, nitrite (NO(2)(-)) and nitrate (NO(3)(-)), are raised in human serum during infection. Low phagolysosomal pH is critical for the macrophage to destroy the engulfed pathogen. This acidic environment may allow synthesis of NO independently of iNOS via dismutation of NO(2)(-)to NO. Should this mechanism be active, assay for iNOS and NO by determination of NO(2)(-)could be misleading. In human macrophages, acid-induced conversion of imported nitrogen oxides (NOx) may take precedence over iNOS-mediated NO synthesis and should be investigated as a source of NO in these cells.
Collapse
Affiliation(s)
- B H Harvey
- Department of Pharmacology, School of Pharmacy, Faculty of Health Sciences, University of Potchefstroom, Republic of South Africa.
| |
Collapse
|
16
|
Chow CW, Khurana S, Woodside M, Grinstein S, Orlowski J. The epithelial Na(+)/H(+) exchanger, NHE3, is internalized through a clathrin-mediated pathway. J Biol Chem 1999; 274:37551-8. [PMID: 10608808 DOI: 10.1074/jbc.274.53.37551] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Trafficking of the Na(+)/H(+) exchanger isoform 3 (NHE3) between sub-apical vesicles and apical membrane of epithelial cells is a suggested mechanism of regulation of NHE3 activity. When epitope-tagged NHE3 was stably expressed in NHE-deficient Chinese hamster ovary cells, a sizable fraction was found in recycling endosomes. This system was used to analyze the mechanism of endocytosis of NHE3. Immunofluorescence and radiolabeling experiments showed that inhibition of clathrin-mediated endocytosis using hypertonicity, acid treatment, or K(+) depletion inhibited internalization of NHE3. Moreover, transient transfection of an inhibitory mutant of dynamin (DynS45N) blocked the clathrin-mediated uptake of transferrin, as well as the endocytosis of NHE3. In ileal villus cells, endogenous NHE3 was also found to co-purify with isolated clathrin-coated vesicles, thereby confirming their association in native tissues. The role of COP-I subunits in the intracellular traffic of NHE3 was evaluated using ldlF cells, which bear a temperature-sensitive mutation in the epsilon-COP subunit. At the permissive temperature, NHE3 distributed normally, whereas at the restrictive temperature, which induces rapid degradation of epsilon-COP, NHE3 was still internalized, but its subcellular distribution was altered. These results indicate that endocytosis of NHE3 occurs primarily via clathrin-coated pits and vesicles and that normal intracellular trafficking of NHE3 involves an epsilon-COP-dependent step.
Collapse
Affiliation(s)
- C W Chow
- Division of Respiratory Medicine, Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | | | | | | |
Collapse
|
17
|
Chow CW, Woodside M, Demaurex N, Yu FH, Plant P, Rotin D, Grinstein S, Orlowski J. Proline-rich motifs of the Na+/H+ exchanger 2 isoform. Binding of Src homology domain 3 and role in apical targeting in epithelia. J Biol Chem 1999; 274:10481-8. [PMID: 10187839 DOI: 10.1074/jbc.274.15.10481] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The NHE2 isoform of the Na+/H+ exchanger (NHE) displays two proline-rich sequences in its C-terminal region that resemble SH3 (Src homology 3)-binding domains. We investigated whether these regions (743PPSVTPAP750, termed Pro-1, and 786VPPKPPP792, termed Pro-2) can bind to SH3 domains and whether they are essential for NHE2 function and targeting. A fusion protein containing the Pro-1 region showed promiscuous binding to SH3 domains of several proteins in vitro, whereas a Pro-2 fusion bound preferentially to domains derived from kinases. In contrast, cytoplasmic regions of NHE1, NHE3, or NHE4 failed to interact. When expressed in antiporter-deficient cells, truncated NHE2 lacking both Pro-rich regions catalyzed Na+/H+ exchange, retained sensitivity to intracellular ATP, and was activated by hyperosmolarity, resembling full-length NHE2. The role of the Pro-rich regions in subcellular targeting was examined by transfection of epitope-tagged forms of NHE2 in porcine renal epithelial LLC-PK1 cells. Both full-length and Pro-2-truncated NHE2 localized almost exclusively to the apical membrane. By contrast, a mutant devoid of both Pro-1 and Pro-2 was preferentially sorted to the basolateral surface but also accumulated intracellularly. These observations indicate that the region encompassing Pro-1 is essential for appropriate subcellular targeting of NHE2.
Collapse
Affiliation(s)
- C W Chow
- Cell Biology Programme, Hospital for Sick Children, University of Toronto, Ontario M5G 1X8, Canada
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Witthöft T, Eckmann L, Kim JM, Kagnoff MF. Enteroinvasive bacteria directly activate expression of iNOS and NO production in human colon epithelial cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:G564-71. [PMID: 9724270 DOI: 10.1152/ajpgi.1998.275.3.g564] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In these studies, we investigated whether bacterial infection of human colon epithelial cells is a sufficient stimulus to upregulate epithelial cell expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production. Human colon epithelial cells (Caco-2 and HT-29) rapidly upregulated iNOS mRNA and protein expression and NO production after infection with enteroinvasive Escherichia coli, Salmonella dublin, or Shigella flexneri but not after infection with noninvasive E. coli or an invasion-deficient mutant of S. dublin. Bacterial infection in the absence of added cytokines was as potent or more potent a stimulus of iNOS expression and NO production as stimulation of cells with combinations of cytokines known to strongly upregulate this epithelial cell response. Enteroinvasive E. coli increased epithelial NO production to a greater extent than S. dublin, although S. dublin was a stronger stimulus of epithelial cell interleukin-8 (IL-8) production. After enteroinvasive E. coli infection of polarized epithelial cell monolayers, nitrite, a stable NO end product, was released predominately into the apical compartment early after infection, whereas IL-8 was released in parallel into the basolateral compartment. These studies suggest NO and/or its redox products are an important component of the intestinal epithelial cell response to microbial infection.
Collapse
Affiliation(s)
- T Witthöft
- Department of Medicine, University of California, San Diego, La Jolla, California 92093-0623, USA
| | | | | | | |
Collapse
|
19
|
Ellis G, Adatia I, Yazdanpanah M, Makela SK. Nitrite and nitrate analyses: a clinical biochemistry perspective. Clin Biochem 1998; 31:195-220. [PMID: 9646943 DOI: 10.1016/s0009-9120(98)00015-0] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To review the assays available for measurement of nitrite and nitrate ions in body fluids and their clinical applications. DESIGN AND METHODS Literature searches were done of Medline and Current Contents to November 1997. RESULTS The influence of dietary nitrite and nitrate on the concentrations of these ions in various body fluids is reviewed. An overview is presented of the metabolism of nitric oxide (which is converted to nitrite and nitrate). Methods for measurement of the ions are reviewed. Reference values are summarized and the changes reported in various clinical conditions. These include: infection, gastroenterological conditions, hypertension, renal and cardiac disease, inflammatory diseases, transplant rejection, diseases of the central nervous system, and others. Possible effects of environmental nitrite and nitrate on disease incidence are reviewed. CONCLUSIONS Most studies of changes in human disease have been descriptive. Diagnostic utility is limited because the concentrations in a significant proportion of affected individuals overlap with those in controls. Changes in concentration may also be caused by diet, outside the clinical investigational setting. The role of nitrite and nitrate assays (alongside direct measurements of nitric oxide in breath) may be restricted to the monitoring of disease progression, or response to therapy in individual patients or subgroups. Associations between disease incidence and drinking water nitrate content are controversial (except for methemoglobinemia in infants).
Collapse
Affiliation(s)
- G Ellis
- Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada
| | | | | | | |
Collapse
|
20
|
Moss J, Stanley S, Nightingale M, Murtagh JJ, Monaco L, Mishima K, Chen H, Williamson K, Tsai S. Molecular and immunological characterization of ADP-ribosylarginine hydrolases. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50043-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|