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Fang XY, Qi LW, Chen HF, Gao P, Zhang Q, Leng RX, Fan YG, Li BZ, Pan HF, Ye DQ. The Interaction Between Dietary Fructose and Gut Microbiota in Hyperuricemia and Gout. Front Nutr 2022; 9:890730. [PMID: 35811965 PMCID: PMC9257186 DOI: 10.3389/fnut.2022.890730] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 04/14/2022] [Indexed: 12/12/2022] Open
Abstract
With the worldwide epidemics of hyperuricemia and associated gout, the diseases with purine metabolic disorders have become a serious threat to human public health. Accumulating evidence has shown that they have been linked to increased consumption of fructose in humans, we hereby made a timely review on the roles of fructose intake and the gut microbiota in regulating purine metabolism, together with the potential mechanisms by which excessive fructose intake contributes to hyperuricemia and gout. To this end, we focus on the understanding of the interaction between a fructose-rich diet and the gut microbiota in hyperuricemia and gout to seek for safe, cheap, and side-effect-free clinical interventions. Furthermore, fructose intake recommendations for hyperuricemia and gout patients, as well as the variety of probiotics and prebiotics with uric acid-lowering effects targeting the intestinal tract are also summarized to provide reference and guidance for the further research.
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Affiliation(s)
- Xin-yu Fang
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Liang-wei Qi
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Hai-feng Chen
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Peng Gao
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Qin Zhang
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Rui-xue Leng
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Yin-guang Fan
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Bao-zhu Li
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
| | - Hai-feng Pan
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
| | - Dong-qing Ye
- Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, China
- Inflammation and Immune Mediated Diseases Laboratory of Anhui, Hefei, China
- *Correspondence: Dong-qing Ye
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2
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Vallon V, Nakagawa T. Renal Tubular Handling of Glucose and Fructose in Health and Disease. Compr Physiol 2021; 12:2995-3044. [PMID: 34964123 PMCID: PMC9832976 DOI: 10.1002/cphy.c210030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The proximal tubule of the kidney is programmed to reabsorb all filtered glucose and fructose. Glucose is taken up by apical sodium-glucose cotransporters SGLT2 and SGLT1 whereas SGLT5 and potentially SGLT4 and GLUT5 have been implicated in apical fructose uptake. The glucose taken up by the proximal tubule is typically not metabolized but leaves via the basolateral facilitative glucose transporter GLUT2 and is returned to the systemic circulation or used as an energy source by distal tubular segments after basolateral uptake via GLUT1. The proximal tubule generates new glucose in metabolic acidosis and the postabsorptive phase, and fructose serves as an important substrate. In fact, under physiological conditions and intake, fructose taken up by proximal tubules is primarily utilized for gluconeogenesis. In the diabetic kidney, glucose is retained and gluconeogenesis enhanced, the latter in part driven by fructose. This is maladaptive as it sustains hyperglycemia. Moreover, renal glucose retention is coupled to sodium retention through SGLT2 and SGLT1, which induces secondary deleterious effects. SGLT2 inhibitors are new anti-hyperglycemic drugs that can protect the kidneys and heart from failing independent of kidney function and diabetes. Dietary excess of fructose also induces tubular injury. This can be magnified by kidney formation of fructose under pathological conditions. Fructose metabolism is linked to urate formation, which partially accounts for fructose-induced tubular injury, inflammation, and hemodynamic alterations. Fructose metabolism favors glycolysis over mitochondrial respiration as urate suppresses aconitase in the tricarboxylic acid cycle, and has been linked to potentially detrimental aerobic glycolysis (Warburg effect). © 2022 American Physiological Society. Compr Physiol 12:2995-3044, 2022.
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Affiliation(s)
- Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, California, USA,Department of Pharmacology, University of California San Diego, La Jolla, California, USA,VA San Diego Healthcare System, San Diego, California, USA,Correspondence to and
| | - Takahiko Nakagawa
- Division of Nephrology, Rakuwakai-Otowa Hospital, Kyoto, Japan,Correspondence to and
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3
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Nakagawa T, Kang DH. Fructose in the kidney: from physiology to pathology. Kidney Res Clin Pract 2021; 40:527-541. [PMID: 34781638 PMCID: PMC8685370 DOI: 10.23876/j.krcp.21.138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/13/2021] [Indexed: 11/30/2022] Open
Abstract
The Warburg effect is a unique property of cancer cells, in which glycolysis is activated instead of mitochondrial respiration despite oxygen availability. However, recent studies found that the Warburg effect also mediates non-cancer disorders, including kidney disease. Currently, diabetes or glucose has been postulated to mediate the Warburg effect in the kidney, but it is of importance that the Warburg effect can be induced under nondiabetic conditions. Fructose is endogenously produced in several organs, including the kidney, under both physiological and pathological conditions. In the kidney, fructose is predominantly metabolized in the proximal tubules; under normal physiologic conditions, fructose is utilized as a substrate for gluconeogenesis and contributes to maintain systemic glucose concentration under starvation conditions. However, when present in excess, fructose likely becomes deleterious, possibly due in part to excessive uric acid, which is a by-product of fructose metabolism. A potential mechanism is that uric acid suppresses aconitase in the Krebs cycle and therefore reduces mitochondrial oxidation. Consequently, fructose favors glycolysis over mitochondrial respiration, a process that is similar to the Warburg effect in cancer cells. Activation of glycolysis also links to several side pathways, including the pentose phosphate pathway, hexosamine pathway, and lipid synthesis, to provide biosynthetic precursors as fuel for renal inflammation and fibrosis. We now hypothesize that fructose could be the mediator for the Warburg effect in the kidney and a potential mechanism for chronic kidney disease.
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Affiliation(s)
| | - Duk-Hee Kang
- Division of Nephrology, Department of Internal Medicine, Ewha Medical Research Institute, Ewha Womans University College of Medicine, Seoul, Republic of Korea
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4
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Ahmad AA, Draves SO, Rosca M. Mitochondria in Diabetic Kidney Disease. Cells 2021; 10:cells10112945. [PMID: 34831168 PMCID: PMC8616075 DOI: 10.3390/cells10112945] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 12/11/2022] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of end stage renal disease (ESRD) in the USA. The pathogenesis of DKD is multifactorial and involves activation of multiple signaling pathways with merging outcomes including thickening of the basement membrane, podocyte loss, mesangial expansion, tubular atrophy, and interstitial inflammation and fibrosis. The glomerulo-tubular balance and tubule-glomerular feedback support an increased glomerular filtration and tubular reabsorption, with the latter relying heavily on ATP and increasing the energy demand. There is evidence that alterations in mitochondrial bioenergetics in kidney cells lead to these pathologic changes and contribute to the progression of DKD towards ESRD. This review will focus on the dialogue between alterations in bioenergetics in glomerular and tubular cells and its role in the development of DKD. Alterations in energy substrate selection, electron transport chain, ATP generation, oxidative stress, redox status, protein posttranslational modifications, mitochondrial dynamics, and quality control will be discussed. Understanding the role of bioenergetics in the progression of diabetic DKD may provide novel therapeutic approaches to delay its progression to ESRD.
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5
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Helsley RN, Moreau F, Gupta MK, Radulescu A, DeBosch B, Softic S. Tissue-Specific Fructose Metabolism in Obesity and Diabetes. Curr Diab Rep 2020; 20:64. [PMID: 33057854 DOI: 10.1007/s11892-020-01342-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/10/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE OF REVIEW The objective of this review is to provide up-to-date and comprehensive discussion of tissue-specific fructose metabolism in the context of diabetes, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD). RECENT FINDINGS Increased intake of dietary fructose is a risk factor for a myriad of metabolic complications. Tissue-specific fructose metabolism has not been well delineated in terms of its contribution to detrimental health effects associated with fructose intake. Since inhibitors targeting fructose metabolism are being developed for the management of NAFLD and diabetes, it is essential to recognize how inability of one tissue to metabolize fructose may affect metabolism in the other tissues. The primary sites of fructose metabolism are the liver, intestine, and kidney. Skeletal muscle and adipose tissue can also metabolize a large portion of fructose load, especially in the setting of ketohexokinase deficiency, the rate-limiting enzyme of fructose metabolism. Fructose can also be sensed by the pancreas and the brain, where it can influence essential functions involved in energy homeostasis. Lastly, fructose is metabolized by the testes, red blood cells, and lens of the eye where it may contribute to infertility, advanced glycation end products, and cataracts, respectively. An increase in sugar intake, particularly fructose, has been associated with the development of obesity and its complications. Inhibition of fructose utilization in tissues primary responsible for its metabolism alters consumption in other tissues, which have not been traditionally regarded as important depots of fructose metabolism.
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Affiliation(s)
- Robert N Helsley
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, 40506, USA
| | - Francois Moreau
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA
| | - Manoj K Gupta
- Islet Cell and Regenerative Medicine, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA, 02215, USA
| | - Aurelia Radulescu
- Department of Pediatrics, University of Kentucky College of Medicine and Kentucky Children's Hospital, Lexington, KY, 40536, USA
| | - Brian DeBosch
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63131, USA
| | - Samir Softic
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY, 40506, USA.
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA, USA.
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, 138 Leader Ave, Lexington, KY, 40506, USA.
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6
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Yamamoto S, Yamamoto M, Nakamura J, Mii A, Yamamoto S, Takahashi M, Kaneko K, Uchino E, Sato Y, Fukuma S, Imamura H, Matsuda M, Yanagita M. Spatiotemporal ATP Dynamics during AKI Predict Renal Prognosis. J Am Soc Nephrol 2020; 31:2855-2869. [PMID: 33046532 DOI: 10.1681/asn.2020050580] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/10/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Depletion of ATP in renal tubular cells plays the central role in the pathogenesis of kidney diseases. Nevertheless, inability to visualize spatiotemporal in vivo ATP distribution and dynamics has hindered further analysis. METHODS A novel mouse line systemically expressing an ATP biosensor (an ATP synthase subunit and two fluorophores) revealed spatiotemporal ATP dynamics at single-cell resolution during warm and cold ischemic reperfusion (IR) with two-photon microscopy. This experimental system enabled quantification of fibrosis 2 weeks after IR and assessment of the relationship between the ATP recovery in acute phase and fibrosis in chronic phase. RESULTS Upon ischemia induction, the ATP levels of proximal tubule (PT) cells decreased to the nadir within a few minutes, whereas those of distal tubule (DT) cells decreased gradually up to 1 hour. Upon reperfusion, the recovery rate of ATP in PTs was slower with longer ischemia. In stark contrast, ATP in DTs was quickly rebounded irrespective of ischemia duration. Morphologic changes of mitochondria in the acute phase support the observation of different ATP dynamics in the two segments. Furthermore, slow and incomplete ATP recovery of PTs in the acute phase inversely correlated with fibrosis in the chronic phase. Ischemia under conditions of hypothermia resulted in more rapid and complete ATP recovery with less fibrosis, providing a proof of concept for use of hypothermia to protect kidney tissues. CONCLUSIONS Visualizing spatiotemporal ATP dynamics during IR injury revealed higher sensitivity of PT cells to ischemia compared with DT cells in terms of energy metabolism. The ATP dynamics of PTs in AKI might provide prognostic information.
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Affiliation(s)
- Shinya Yamamoto
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masamichi Yamamoto
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Advanced Scientific Research Leaders Development Unit, Gunma University Graduate School of Medicine, Maebashi, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| | - Jin Nakamura
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akiko Mii
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shigenori Yamamoto
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masahiro Takahashi
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Keiichi Kaneko
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Eiichiro Uchino
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yuki Sato
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.,Medical Innovation Center TMK Project, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shingo Fukuma
- Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiromi Imamura
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Michiyuki Matsuda
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Motoko Yanagita
- Department of Nephrology, Graduate School of Medicine, Kyoto University, Kyoto, Japan .,Institute for the Advanced Study of Human Biology, Kyoto University, Kyoto, Japan
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7
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Investigation of a Pharmacological Approach for Reduction of Renal Uptake of Radiolabeled ADAPT Scaffold Protein. Molecules 2020; 25:molecules25194448. [PMID: 32998229 PMCID: PMC7583817 DOI: 10.3390/molecules25194448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022] Open
Abstract
Albumin binding domain-Derived Affinity ProTeins (ADAPTs) are small (5 kDa) engineered scaffold proteins that are promising targeting agents for radionuclide-based imaging. A recent clinical study has demonstrated that radiolabeled ADAPTs can efficiently visualize human epidermal growth factor receptor 2 (HER2) expression in breast cancer using SPECT imaging. However, the use of ADAPTs directly labeled with radiometals for targeted radionuclide therapy is limited by their high reabsorption and prolonged retention of activity in kidneys. In this study, we investigated whether a co-injection of lysine or gelofusin, commonly used for reduction of renal uptake of radiolabeled peptides in clinics, would reduce the renal uptake of [99mTc]Tc(CO)3-ADAPT6 in NMRI mice. In order to better understand the mechanism behind the reabsorption of [99mTc]Tc(CO)3-ADAPT6, we included several compounds that act on various parts of the reabsorption system in kidneys. Administration of gelofusine, lysine, probenecid, furosemide, mannitol, or colchicine did not change the uptake of [99mTc]Tc(CO)3-ADAPT6 in kidneys. Sodium maleate reduced the uptake of [99mTc]Tc(CO)3-ADAPT6 to ca. 25% of the uptake in the control, a high dose of fructose (50 mmol/kg) reduced the uptake by ca. two-fold. However, a lower dose (20 mmol/kg) had no effect. These results indicate that common clinical strategies are not effective for reduction of kidney uptake of [99mTc]Tc(CO)3-ADAPT6 and that other strategies for reduction of activity uptake or retention in kidneys should be investigated for ADAPT6.
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8
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Garousi J, Vorobyeva A, Altai M. Influence of Several Compounds and Drugs on the Renal Uptake of Radiolabeled Affibody Molecules. Molecules 2020; 25:molecules25112673. [PMID: 32526905 PMCID: PMC7321166 DOI: 10.3390/molecules25112673] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 12/19/2022] Open
Abstract
Affibody molecules are the most studied class of engineered scaffold proteins (ESPs) in radionuclide molecular imaging. Attempts to use affibody molecules directly labelled with radiometals for targeted radionuclide therapy were hampered by the high uptake and retention of radioactivity in kidneys. Several promising strategies have been implemented to circumvent this problem. Here, we investigated whether a pharmacological approach targeting different components of the reabsorption system could be used to lower the uptake of [99mTc]Tc-ZHER:2395 affibody molecule in kidneys. Pre-injection of probenecid, furosemide, mannitol or colchicine had no influence on activity uptake in kidneys compared to the control group. Mice pre-injected with maleate and fructose had 33% and 51% reduction in the kidney-associated activity, respectively, compared to the control group. Autoradiography images showed that the accumulation of activity after [99mTc]Tc-ZHER2:2395 injection was in the renal cortex and that both maleate and fructose could significantly reduce it. Results from this study demonstrate that pharmacological intervention with maleate and fructose was effective in reducing the kidney uptake of affibody molecules. A presumable mechanism is the disruption of ATP-mediated cellular uptake and endocytosis processes of affibody molecules by tubular cells.
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Affiliation(s)
- Javad Garousi
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden; (J.G.); (A.V.)
| | - Anzhelika Vorobyeva
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden; (J.G.); (A.V.)
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 634 050 Tomsk, Russia
| | - Mohamed Altai
- Division of Oncology and Pathology, Kamprad Lab, Department of Clinical Sciences, Lund University, 222 43 Lund, Sweden
- Correspondence: ; Tel.: +46-704128699
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9
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Nakagawa T, Johnson RJ, Andres-Hernando A, Roncal-Jimenez C, Sanchez-Lozada LG, Tolan DR, Lanaspa MA. Fructose Production and Metabolism in the Kidney. J Am Soc Nephrol 2020; 31:898-906. [PMID: 32253274 DOI: 10.1681/asn.2019101015] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Understanding fructose metabolism might provide insights to renal pathophysiology. To support systemic glucose concentration, the proximal tubular cells reabsorb fructose as a substrate for gluconeogenesis. However, in instances when fructose intake is excessive, fructose metabolism is costly, resulting in energy depletion, uric acid generation, inflammation, and fibrosis in the kidney. A recent scientific advance is the discovery that fructose can be endogenously produced from glucose under pathologic conditions, not only in kidney diseases, but also in diabetes, in cardiac hypertrophy, and with dehydration. Why humans have such a deleterious mechanism to produce fructose is unknown, but it may relate to an evolutionary benefit in the past. In this article, we aim to illuminate the roles of fructose as it relates to gluconeogenesis and fructoneogenesis in the kidney.
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Affiliation(s)
- Takahiko Nakagawa
- Department of Nephrology, Rakuwakai Otowa Hospital, Kyoto, Japan .,Department of Biochemistry, Shiga University of Medical Science, Shiga, Japan
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado
| | - Ana Andres-Hernando
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado
| | - Carlos Roncal-Jimenez
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado
| | - Laura G Sanchez-Lozada
- Department of Cardio-Renal Physiopathology, National Institute of Cardiology Ignacio Chavez, Mexico City, Mexico
| | - Dean R Tolan
- Department of Biology, Boston University, Boston, Massachusetts
| | - Miguel A Lanaspa
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado
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10
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Altai M, Garousi J, Rinne SS, Schulga A, Deyev S, Vorobyeva A. On the prevention of kidney uptake of radiolabeled DARPins. EJNMMI Res 2020; 10:7. [PMID: 32020413 PMCID: PMC7000568 DOI: 10.1186/s13550-020-0599-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 01/17/2020] [Indexed: 12/27/2022] Open
Abstract
Background Designed ankyrin repeat proteins (DARPins) are small engineered scaffold proteins (14–18 kDa) that demonstrated promising tumor-targeting properties in preclinical studies. However, high renal accumulation of activity for DARPins labeled with residualizing labels is a limitation for targeted radionuclide therapy. A better understanding of the mechanisms behind the kidney uptake of DARPins could aid the development of strategies to reduce it. In this study, we have investigated whether the renal uptake of [99mTc]Tc(CO)3-G3 DARPin could be reduced by administration of compounds that act on various parts of the reabsorption system in the kidney. Results Co-injection of lysine or Gelofusine was not effective for the reduction of kidney uptake of [99mTc]Tc(CO)3-G3. Administration of sodium maleate before the injection of [99mTc]Tc(CO)3-G3 reduced the kidney-associated activity by 60.4 ± 10.3%, while administration of fructose reduced it by 46.9 ± 7.6% compared with the control. The decrease in the kidney uptake provided by sodium maleate was also observed for [99mTc]Tc(CO)3-9_29 DARPin. Preinjection of colchicine, probenecid, mannitol, or furosemide had no effect on the kidney uptake of [99mTc]Tc(CO)3-G3. Kidney autoradiography showed mainly cortical accumulation of activity for all studied groups. Conclusion Common clinical strategies were not effective for the reduction of kidney uptake of [99mTc]Tc(CO)3-G3. Both fructose and maleate lower the cellular ATP level in the proximal tubule cells and their reduction of the kidney reuptake indicates the involvement of an ATP-driven uptake mechanism. The decrease provided by maleate for both G3 and 9_29 DARPins indicates that their uptake proceeds through a mechanism independent of DARPin structure and binding site composition.
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Affiliation(s)
- Mohamed Altai
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Javad Garousi
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - Sara S Rinne
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Alexey Schulga
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Sergey Deyev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,National Research Tomsk Polytechnic University, Tomsk, Russia.,Center of Biomedical Engineering, Sechenov University, Moscow, Russia
| | - Anzhelika Vorobyeva
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185, Uppsala, Sweden. .,National Research Tomsk Polytechnic University, Tomsk, Russia.
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11
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Eren OC, Ortiz A, Afsar B, Covic A, Kuwabara M, Lanaspa MA, Johnson RJ, Kanbay M. Multilayered Interplay Between Fructose and Salt in Development of Hypertension. Hypertension 2019; 73:265-272. [PMID: 30595116 DOI: 10.1161/hypertensionaha.118.12150] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ozgur C Eren
- Department of Medicine, Koç University School of Medicine, Istanbul, Turkey (O.C.E., M. Kanbay)
| | - Alberto Ortiz
- Dialysis Unit, School of Medicine, IIS-Fundacion Jimenez Diaz, Universidad Autónoma de Madrid, Spain (A.O.)
| | - Baris Afsar
- Division of Nephrology, Department of Medicine, Suleyman Demirel University School of Medicine, Isparta, Turkey (B.A.)
| | - Adrian Covic
- Nephrology Clinic, Dialysis and Renal Transplant Center, 'C.I. PARHON' University Hospital, and 'Grigore T. Popa' University of Medicine, Iasi, Romania (A.C.)
| | - Masanari Kuwabara
- Department of Cardiology, Toranomon Hospital, Tokyo, Japan (M. Kuwabara)
| | - Miguel A Lanaspa
- Division of Renal Diseases and Hypertension, School of Medicine, University of Colorado Denver, Aurora (M.A.L., R.J.J.)
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, School of Medicine, University of Colorado Denver, Aurora (M.A.L., R.J.J.)
| | - Mehmet Kanbay
- From the Division of Nephrology, Koç University School of Medicine, Istanbul, Turkey (M. Kanbay).,Department of Medicine, Koç University School of Medicine, Istanbul, Turkey (O.C.E., M. Kanbay)
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12
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Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
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Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
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13
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Abstract
The kidney requires a large number of mitochondria to remove waste from the blood and regulate fluid and electrolyte balance. Mitochondria provide the energy to drive these important functions and can adapt to different metabolic conditions through a number of signalling pathways (for example, mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) pathways) that activate the transcriptional co-activator peroxisome proliferator-activated receptor-γ co-activator 1α (PGC1α), and by balancing mitochondrial dynamics and energetics to maintain mitochondrial homeostasis. Mitochondrial dysfunction leads to a decrease in ATP production, alterations in cellular functions and structure, and the loss of renal function. Persistent mitochondrial dysfunction has a role in the early stages and progression of renal diseases, such as acute kidney injury (AKI) and diabetic nephropathy, as it disrupts mitochondrial homeostasis and thus normal kidney function. Improving mitochondrial homeostasis and function has the potential to restore renal function, and administering compounds that stimulate mitochondrial biogenesis can restore mitochondrial and renal function in mouse models of AKI and diabetes mellitus. Furthermore, inhibiting the fission protein dynamin 1-like protein (DRP1) might ameliorate ischaemic renal injury by blocking mitochondrial fission.
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14
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Xu C, Lu A, Lu X, Zhang L, Fang H, Zhou L, Yang T. Activation of Renal (Pro)Renin Receptor Contributes to High Fructose-Induced Salt Sensitivity. Hypertension 2016; 69:339-348. [PMID: 27993957 DOI: 10.1161/hypertensionaha.116.08240] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/09/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022]
Abstract
A high-fructose diet is shown to induce salt-sensitive hypertension, but the underlying mechanism largely remains unknown. The major goal of the present study was to test the role of renal (pro)renin receptor (PRR) in this model. In Sprague-Dawley rats, high-fructose intake increased renal expression of full-length PRR, which were attenuated by allopurinol. High-fructose intake also upregulated renal mRNA and protein expression of sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter, as well as in vivo Na/K/2Cl cotransporter activity, all of which were nearly completely blocked by a PRR decoy inhibitor PRO20 or allopurinol treatment. Parallel changes were observed for indices of intrarenal renin-angiotensin-system including renal and urinary renin and angiotensin II levels. Radiotelemetry demonstrated that high-fructose or a high-salt diet alone did not affect mean arterial pressure, but the combination of the 2 maneuvers induced a ≈10-mm Hg increase of mean arterial pressure, which was blunted by PRO20 or allopurinol treatment. In cultured human kidney 2 cells, both fructose and uric acid increased protein expression of soluble PRR in a time- and dose-dependent manner; fructose-induced PRR upregulation was inhibited by allopurinol. Taken together, our data suggest that fructose via uric acid stimulates renal expression of PRR/soluble PRR that stimulate sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter expression and intrarenal renin-angiotensin system to induce salt-sensitive hypertension.
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Affiliation(s)
- Chuanming Xu
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Aihua Lu
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Xiaohan Lu
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Linlin Zhang
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Hui Fang
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Li Zhou
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.)
| | - Tianxin Yang
- From the Institute of Hypertension, Sun Yat-Sen University School of Medicine, Guangzhou, China (C.X., A.L., X.L., L.Z., H.F., L.Z., T.Y.); Internal Medicine, University of Utah, Salt Lake City (C.X., X.L., T.Y.); and Veterans Affairs Medical Center, Salt Lake City, Utah (X.L., T.Y.).
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15
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Lanaspa MA, Ishimoto T, Cicerchi C, Tamura Y, Roncal-Jimenez CA, Chen W, Tanabe K, Andres-Hernando A, Orlicky DJ, Finol E, Inaba S, Li N, Rivard CJ, Kosugi T, Sanchez-Lozada LG, Petrash JM, Sautin YY, Ejaz AA, Kitagawa W, Garcia GE, Bonthron DT, Asipu A, Diggle CP, Rodriguez-Iturbe B, Nakagawa T, Johnson RJ. Endogenous fructose production and fructokinase activation mediate renal injury in diabetic nephropathy. J Am Soc Nephrol 2014; 25:2526-38. [PMID: 24876114 DOI: 10.1681/asn.2013080901] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Diabetes is associated with activation of the polyol pathway, in which glucose is converted to sorbitol by aldose reductase. Previous studies focused on the role of sorbitol in mediating diabetic complications. However, in the proximal tubule, sorbitol can be converted to fructose, which is then metabolized largely by fructokinase, also known as ketohexokinase, leading to ATP depletion, proinflammatory cytokine expression, and oxidative stress. We and others recently identified a potential deleterious role of dietary fructose in the generation of tubulointerstitial injury and the acceleration of CKD. In this study, we investigated the potential role of endogenous fructose production, as opposed to dietary fructose, and its metabolism through fructokinase in the development of diabetic nephropathy. Wild-type mice with streptozotocin-induced diabetes developed proteinuria, reduced GFR, and renal glomerular and proximal tubular injury. Increased renal expression of aldose reductase; elevated levels of renal sorbitol, fructose, and uric acid; and low levels of ATP confirmed activation of the fructokinase pathway. Furthermore, renal expression of inflammatory cytokines with macrophage infiltration was prominent. In contrast, diabetic fructokinase-deficient mice demonstrated significantly less proteinuria, renal dysfunction, renal injury, and inflammation. These studies identify fructokinase as a novel mediator of diabetic nephropathy and document a novel role for endogenous fructose production, or fructoneogenesis, in driving renal disease.
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Affiliation(s)
- Miguel A Lanaspa
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado;
| | - Takuji Ishimoto
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Christina Cicerchi
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Yoshifuru Tamura
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Carlos A Roncal-Jimenez
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Wei Chen
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Katsuyuki Tanabe
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Ana Andres-Hernando
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - David J Orlicky
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Esteban Finol
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado; Venezuelan Scientific Research Institute and University Hospital of Zulia, Maracaibo, Venezuela
| | - Shinichiro Inaba
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Nanxing Li
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Christopher J Rivard
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Tomoki Kosugi
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Laura G Sanchez-Lozada
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado; Laboratory of Renal Physiopathology and Department of Nephrology, INC Ignacio Chavez, Mexico City, Mexico
| | - J Mark Petrash
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | | | - A Ahsan Ejaz
- Division of Nephrology, Hypertension, and Transplantation, University of Florida, Gainesville, Florida
| | - Wataru Kitagawa
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - Gabriela E Garcia
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
| | - David T Bonthron
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, United Kingdom; and
| | - Aruna Asipu
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, United Kingdom; and
| | - Christine P Diggle
- Leeds Institute of Biomedical & Clinical Sciences, University of Leeds, Leeds, United Kingdom; and
| | | | - Takahiko Nakagawa
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado; TMK Project, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Richard J Johnson
- The Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado, Denver, Colorado
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16
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Cabral PD, Hong NJ, Hye Khan MA, Ortiz PA, Beierwaltes WH, Imig JD, Garvin JL. Fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. Hypertension 2013; 63:e68-73. [PMID: 24379189 DOI: 10.1161/hypertensionaha.113.02564] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The proximal nephron reabsorbs 60% to 70% of the fluid and sodium and most of the filtered bicarbonate via Na/H exchanger 3. Enhanced proximal nephron transport is implicated in hypertension. Our findings show that a fructose-enriched diet causes salt sensitivity. We hypothesized that fructose stimulates luminal Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. Na/H exchange was measured in rat proximal tubules as the rate of intracellular pH (pHi) recovery in fluorescent units/s. Replacing 5 mmol/L glucose with 5 mmol/L fructose increased the rate of pHi recovery (1.8±0.6 fluorescent units/s; P<0.02; n=8). Staurosporine, a protein kinase C inhibitor, blocked this effect. We studied whether this effect was because of the addition of fructose or removal of glucose. The basal rate of pHi recovery was first tested in the presence of a 0.6-mmol/L glucose and 1, 3, or 5 mmol/L fructose added in a second period. The rate of pHi recovery did not change with 1 mmol/L but it increased with 3 and 5 mmol/L of fructose. Adding 5 mmol/L glucose caused no change. Removal of luminal sodium blocked pHi recovery. With 5.5 mmol/L glucose, angiotensin II (1 pmol/L) did not affect the rate of pHi recovery (change, -1.1±0.5 fluorescent units/s; n=9) but it increased the rate of pHi recovery with 0.6 mmol/L glucose/5 mmol/L fructose (change, 4.0±2.2 fluorescent units/s; P<0.02; n=6). We conclude that fructose stimulates Na/H exchange activity and sensitizes the proximal tubule to angiotensin II. This mechanism is likely dependent on protein kinase C. These results may partially explain the mechanism by which a fructose diet induces hypertension.
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Affiliation(s)
- Pablo D Cabral
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106-4970.
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17
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Nakayama T, Kosugi T, Gersch M, Connor T, Sanchez-Lozada LG, Lanaspa MA, Roncal C, Perez-Pozo SE, Johnson RJ, Nakagawa T. Dietary fructose causes tubulointerstitial injury in the normal rat kidney. Am J Physiol Renal Physiol 2010; 298:F712-20. [PMID: 20071464 DOI: 10.1152/ajprenal.00433.2009] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Recent studies suggest that the metabolic syndrome is associated with renal disease. We previously reported that a high-fructose diet, but not a high-glucose diet, can induce metabolic syndrome and accelerate chronic renal disease in rats. We now examined the effects of a high-fructose diet on normal rat kidneys. Three groups of Sprague-Dawley rats were pair fed a special diet containing 60% fructose, 60% glucose, or control standard rat chow for 6 wk, and then histological studies were performed. The effect of fructose to induce cell proliferation in cultured proximal tubular cells was also performed. Fructose diet, but not glucose diet, significantly increased kidney weight by 6 wk. The primary finding was tubular hyperplasia and proliferation involving all segments of the proximal tubules while glomerular changes were not observed. This is the same site where the fructose transporters (GLUT2 and -5) as well as the key enzyme in fructose metabolism (ketohexokinase) were expressed. Consistently, fructose also induced proliferation of rat proximal tubular cells in culture. In vivo, tubular proliferation was also associated with focal tubular injury, with type III collagen deposition in the interstitium, an increase in alpha-smooth muscle actin positive myofibroblasts, and an increase in macrophage infiltration. In conclusion, a high-fructose diet induces cell proliferation and hyperplasia in proximal tubules, perhaps via a direct metabolic effect. The effect is independent of total energy intake and is associated with focal tubulointerstitial injury. These studies may provide a mechanism by which metabolic syndrome causes renal disease.
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Affiliation(s)
- Takahiro Nakayama
- Division of Nephrology, University of Florida, Gainesville, Florida, USA
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18
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Diggle CP, Shires M, Leitch D, Brooke D, Carr IM, Markham AF, Hayward BE, Asipu A, Bonthron DT. Ketohexokinase: expression and localization of the principal fructose-metabolizing enzyme. J Histochem Cytochem 2009; 57:763-74. [PMID: 19365088 DOI: 10.1369/jhc.2009.953190] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Ketohexokinase (KHK, also known as fructokinase) initiates the pathway through which most dietary fructose is metabolized. Very little is known about the cellular localization of this enzyme. Alternatively spliced KHK-C and KHK-A mRNAs are known, but the existence of the KHK-A protein isoform has not been demonstrated in vivo. Using antibodies to KHK for immunohistochemistry and Western blotting of rodent tissues, including those from mouse knockouts, coupled with RT-PCR assays, we determined the distribution of the splice variants. The highly expressed KHK-C isoform localized to hepatocytes in the liver and to the straight segment of the proximal renal tubule. In both tissues, cytoplasmic and nuclear staining was observed. The KHK-A mRNA isoform was observed exclusively in a range of other tissues, and by Western blotting, the presence of endogenous immunoreactive KHK-A protein was shown for the first time, proving that the KHK-A mRNA is translated into KHK-A protein in vivo, and supporting the suggestion that this evolutionarily conserved isoform is physiologically functional. However, the low levels of KHK-A expression prevented its immunohistochemical localization within these tissues. Our results highlight that the use of in vivo biological controls (tissues from knockout animals) is required to distinguish genuine KHK immunoreactivity from experimental artifact.
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Affiliation(s)
- Christine P Diggle
- Leeds Institute of Molecular Medicine, University of Leeds, St James's University Hospital, Beckett Street, Leeds LS9 7TF, United Kingdom
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19
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Cirillo P, Gersch MS, Mu W, Scherer PM, Kim KM, Gesualdo L, Henderson GN, Johnson RJ, Sautin YY. Ketohexokinase-dependent metabolism of fructose induces proinflammatory mediators in proximal tubular cells. J Am Soc Nephrol 2009; 20:545-53. [PMID: 19158351 DOI: 10.1681/asn.2008060576] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Increased consumption of fructose may play an important role in the epidemic of metabolic syndrome and may presage the development of diabetes, cardiovascular disease, and chronic kidney disease. Once in the cell, fructose is phosphorylated by ketohexokinase (KHK), leading to consumption of ATP, formation of AMP, and generation of uric acid through xanthine oxidoreductase (XOR). This study aimed to examine the direct effects of fructose in human kidney proximal tubular cells (HK-2) and whether they are mediated by the fructose metabolism via KHK. At a similar concentration to that observed in peripheral blood after a meal, fructose induced production of monocyte chemotactic protein 1 (MCP-1) and reactive oxygen species in HK-2 cells. Knockdown of KHK by stable transfection with small hairpin RNA demonstrated that these processes were KHK dependent. Several antioxidants, including specific inhibitors of NADPH oxidase and XOR, prevented MCP-1 secretion. We detected XOR mRNA in HK-2 cells and confirmed its activity by identifying uric acid by mass spectrometry. Fructose increased intracellular uric acid, and uric acid induced production of MCP-1 as well. In summary, postprandial concentrations of fructose stimulate redox- and urate-dependent inflammatory mediators in proximal tubular cells.
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Affiliation(s)
- Pietro Cirillo
- Division of Nephrology, Hypertension and Transplantation, Department of Medicine, University of Florida, Gainesville, FL 32610-0224, USA
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20
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Akizawa H, Uehara T, Arano Y. Renal uptake and metabolism of radiopharmaceuticals derived from peptides and proteins. Adv Drug Deliv Rev 2008; 60:1319-28. [PMID: 18508156 DOI: 10.1016/j.addr.2008.04.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 04/16/2008] [Indexed: 11/16/2022]
Abstract
Radiolabeled anti-CD20 antibodies have demonstrated impressive efficacy in the treatment of relapsed non-Hodgkin lymphoma. This encourages the treatment of solid tumor with radiolabeled antibody fragments and peptides. However, both preclinical and clinical studies revealed that persistent localization of radioactivity in the kidney constitutes a major obstacle that compromises therapeutic efficacy. Recent extensive studies show that long residence times of radiolabeled end products from lysosomes are responsible for the renal radioactivity levels. Recent studies have also elucidated the involvement of megalin-cubilin in renal tubular reabsorption of radiolabeled antibody fragments and peptides. In light of these findings, efforts are being made to block tubular reabsorption of radiolabeled antibody fragments and peptides by competitive inhibitors, charge modification, and PEGylation. An interposition of an enzyme-cleavable linkage between antibody fragments and radiolabels would constitute an alternative approach to reduce renal radioactivity levels. Recent findings of these studies will be described.
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Affiliation(s)
- Hiromichi Akizawa
- Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, Japan
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21
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Hwa JS, Kim HJ, Goo BM, Park HJ, Kim CW, Chung KH, Park HC, Chang SH, Kim YW, Kim DR, Cho GJ, Choi WS, Kang KR. The expression of ketohexokinase is diminished in human clear cell type of renal cell carcinoma. Proteomics 2006; 6:1077-84. [PMID: 16372272 DOI: 10.1002/pmic.200401345] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For identification and targeting of tumor-associated marker proteins, the proteome of clear cell type of renal cell carcinoma (RCC) and normal kidney tissues was analyzed by 2-DE. Ketohexokinase (also called fructokinase), which catalyzes the phosphorylation of fructose to fructose 1-phosphate, was identified by MALDI-TOF MS and found to be expressed at low rates in the renal tumor tissues. We found a decreased amount of ketohexokinase mRNA in RCC compared to that observed in the normal kidney tissues by Northern blot. The activity of ketohexokinase in 20 clear cell RCC specimens and the 20 corresponding normal kidneys was investigated, and its activity was shown to be approximately 1.4-fold lower in the RCC specimens than in the normal kidney. Ketohexokinase activity in tumor stage pT3 RCC was 1.5-fold lower than in pT1 RCC. The level of ketohexokinase activity in histological grade 3 RCC was 1.8-fold lower than that in grade 1 cancer. In addition, using in situ hybridization, it was revealed that ketohexokinase in the normal kidney tissue was confined to the proximal tubular epithelial cells, while the expression of ketohexokinase in RCC tissues was extremely low. Our research results show that the expression of human ketohexokinase was diminished in clear cell RCC.
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Affiliation(s)
- Jeong Seok Hwa
- Department of Urology, College of Medicine and Institute of Health Science, Gyeongsang National University, Jinju, South Korea
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22
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Zager RA. Mitochondrial free radical production induces lipid peroxidation during myohemoglobinuria. Kidney Int 1996; 49:741-51. [PMID: 8648915 DOI: 10.1038/ki.1996.103] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Iron catalyzed free radical formation and lipid peroxidation are accepted mechanisms of heme protein-induced acute renal failure. However, the source(s) of those free radicals which trigger lipid peroxidation in proximal tubular cells remains unknown. This study tested the potential involvement of mitochondrial electron transport, xanthine oxidase activity, and arachidonic acid metabolism in the heme-induced peroxidative state. The impact of cytosolic Ca2+ loading also was assessed. Rhabdomyolysis was induced in mice by glycerol injection, and two hours later heme-laden proximal tubular segments (PTS) were isolated for study. PTS from normal mice served as controls. During 30 to 60 minute incubations, heme loaded PTS developed progressive cytotoxicity (LDH release) and iron-dependent lipid peroxidation (malondialdehyde, MDA, generation; inhibited by deferoxamine). Site 2 (antimycin A) or site 3 (cyanide, hypoxia) mitochondrial respiratory chain inhibition completely blocked lipid peroxidation, whereas site 1 inhibition (rotenone) doubled its extent (presumably by shunting NADH through NADH dehydrogenase, a free radical generating system). Conversely, these agents did not substantially alter MDA in normal PTS. Normal and heme loaded PTS developed comparable degrees of LDH release during respiratory blockade irrespective of increased or decreased MDA production (indicating that lipid peroxidation was not a critical determinant of cell death). Neither increasing free arachidonic acid (PLA2 treatment) nor adding cyclooxygenase/lipoxygenase/cytochrome p450 inhibitors conferred a consistent protective effect. Altering free Ca2+ status (chelators; ionophore addition) and xanthine oxidase inhibition had no discernible impacts. Despite mitochondrial free radical production, mitochondrial function, as assessed by the ATP/ADP ratio, seemingly remained intact. In conclusion, (1) the terminal mitochondrial respiratory chain is the dominant source of free radicals which trigger PTS lipid peroxidation; (2) iron is a required secondary factor; (3) although mitochondria fuel lipid peroxidation, they do not appear to be critical targets of the heme-induced oxidant attack.
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Affiliation(s)
- R A Zager
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
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23
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24
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Tilton RG, Baier LD, Harlow JE, Smith SR, Ostrow E, Williamson JR. Diabetes-induced glomerular dysfunction: links to a more reduced cytosolic ratio of NADH/NAD+. Kidney Int 1992; 41:778-88. [PMID: 1513100 DOI: 10.1038/ki.1992.121] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
These studies were undertaken to examine effects of elevated glucose levels on glycolysis, sorbitol pathway activity, and the cytosolic redox state of NADH/NAD+ in isolated glomeruli. Blood-free glomeruli were isolated from kidneys of male, Sprague-Dawley rats using standard sieving techniques, then incubated for one hour at 37 degrees C, pH 7.4, pO2 approximately 500 torr, in Krebs bicarbonate/Hepes buffer containing 5 or 30 mM glucose. Elevated glucose levels increased glucose 6-phosphate, fructose 6-phosphate, total triose phosphates, lactate, the lactate/pyruvate ratio, sorbitol, and fructose, but did not affect sn-glycerol 3-phosphate, pyruvate, or myo-inositol levels. The more reduced glomerular cytosolic redox state (manifested by the tissue lactate/pyruvate ratio) induced by 30 mM glucose was completely abrogated by aldose reductase inhibitors added to the diet two to seven days prior to glomerular isolation. These observations, coupled with evidence linking glucose- and diabetes-induced glomerular dysfunction to increased sorbitol pathway metabolism, support the hypothesis that metabolic imbalances associated with a more reduced ratio of cytosolic NADH/NAD+ (resulting from increased glucose metabolism via the sorbitol pathway) play an important role in mediating glucose- and diabetes-induced glomerular dysfunction.
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Affiliation(s)
- R G Tilton
- Department of Pathology, Washington University School of Medicine, Saint Louis, Missouri
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25
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Proximal Renal Tubular Acidosis (RTA): Normal Proximal Tubule Function and Evidence of Cellular Defects. Nephrology (Carlton) 1991. [DOI: 10.1007/978-3-662-35158-1_117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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26
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Barac-Nieto M, Gupta RK, Spitzer A. NMR studies of phosphate metabolism in the isolated perfused kidney of developing rats. Pediatr Nephrol 1990; 4:392-8. [PMID: 2206909 DOI: 10.1007/bf00862525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During growth, the capacity for renal phosphate (Pi) reabsorption varies as a function of Pi demand. These changes occur in the absence of changes in extracellular concentration of Pi and are also observed in renal cells cultured in defined media. These findings suggest a direct regulatory effect of intracellular Pi on its transport systems. We postulate that a low intracellular Pi concentration [( Pi]i) occurs in the developing kidney as a consequence of differences in Pi metabolism between growing and mature cells and that a low [Pi]i, in turn, leads to adaptive changes in renal Pi transport. In order to assess this hypothesis, we used 31P-nuclear magnetic resonance (NMR) to measure the intracellular concentrations of NMR-visible Pi and phospho-metabolites and the rates of Pi turnover due to adenosine triphosphate (ATP) synthesis, in isolated perfused kidneys of 3- to 4-week-old and 12- to 13-week-old rats. The [Pi]i was lower (1.7 +/- 0.1 vs 2.7 +/- 0.1 mM, P less than 0.05) in kidneys of growing than of adult rats, while the ATP (2.9 +/- 0.3 vs 2.8 +/- 0.5 mM) and adenosine diphosphate (ADP) (-0.2 mM) concentrations were similar at the two ages, consistent with a high phosphorylation potential in the kidneys of the younger animals. Radiofrequency irradiation of the gamma-P of ATP resulted in reduction in the intensity of the Pi resonance of 62 +/- 5% in the newborn and 38 +/- 3% in the adult (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Barac-Nieto
- Albert Einstein College of Medicine, Department of Pediatrics, Bronx, NY 10461
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27
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Shanley PF, Johnson GC. Adenine nucleotides, transport activity and hypoxic necrosis in the thick ascending limb of Henle. Kidney Int 1989; 36:823-30. [PMID: 2615191 DOI: 10.1038/ki.1989.268] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Thick ascending limb of Henle (TAL) necrosis in the isolated perfused kidney is an important model of renal hypoxia, but physiologic and metabolic correlation with this morphologic damage has been inadequate. More precise estimation of TAL adenine nucleotides in this model was obtained in the present study by high pressure liquid chromatography analysis of biopsy samples from the inner stripe of the outer medulla during perfusion. The inner stripe, which is the zone where TAL are concentrated, showed ATP depletion and low adenylate energy charge (AEC) early in perfusion prior to the appearance of TAL necrosis. Free water clearance (CH2O) was used as an estimate of TAL transport activity; the CH2O observed during 90 minute perfusions was found to be predictive of the extent of TAL necrosis in each experiment. The results support the idea that there is significant medullary hypoxia in the isolated perfused kidney and that TAL solute transport is a determinant of injury in this model. In further studies, the effects of ouabain (10(-3) M), furosemide (10(-4) M) or acidosis (pH 7.0 rather than the usual pH 7.4) on TAL transport activity and adenine nucleotide levels were compared. All three maneuvers have been shown previously to reduce TAL injury in the isolated perfused kidney. Addition of ouabain or furosemide reduced CH2O and TAL necrosis in parallel while acidosis had no effect on CH2O during perfusion. Both ouabain and furosemide attenuated ATP depletion and resulted in higher AEC while acidosis had no effect on these indices of cellular hypoxia. Therefore, the mechanism of cytoprotection by acidosis appears distinct from that of ouabain or furosemide.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P F Shanley
- Department of Pathology, University of Colorado Health Sciences Center, Denver
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28
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Kehrer G, Blech M, Kallerhoff M, Kleinert H, Bretschneider HJ. Intraischemic metabolic effects of different disaccharides on protected canine kidneys. UROLOGICAL RESEARCH 1989; 17:371-6. [PMID: 2516381 DOI: 10.1007/bf00510529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The addition of the disaccharides maltose (10, 20, 30 mM) and sucrose (30, 60 mM) to Bretschneider's organ protective HTK solution was evaluated to improve renal protection by an enhanced glycolytic energy supply. Canine kidneys were perfused for 8 min with either HTK solution or HTK solution containing additional disaccharides. After nephrectomy the kidneys were incubated at 25 degrees C and metabolic parameters were determined at regular intervals. Maltose and sucrose are slowly cleaved during renal ischemia but maltose distinctly faster than sucrose. Maltose increases intraischemic ATP supply. However, 30 mM maltose was no better than 10 mM. 60 mM sucrose was about as effective for glycolysis as 10 mM maltose. However, possibly due to fructose release there was an accelerated decrease of adenine nucleotides with sucrose. Although fructose enters glycolysis it seems to have negative side-effects. Hence, probably neither sucrose nor fructose are appropriate for renal substrate supply during ischemia.
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Affiliation(s)
- G Kehrer
- Department of Physiology, University of Göttingen, Federal Republic of Germany
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29
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Kinne RK, Pavenstädt-Grupp I, Grupp C, Jans A, Grunewald RW. [Transport mechanisms and metabolic processes in isolated cells of the collecting tubule of the kidney papilla]. KLINISCHE WOCHENSCHRIFT 1988; 66:836-42. [PMID: 2846946 DOI: 10.1007/bf01728944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Taking into account recent results obtained with isolated papillary collecting duct cells the metabolic pathways and membrane transport systems of collecting duct cells are reviewed. The plasma membranes contain a luminal proton AT-Pase and a contraluminal Cl-/HCO3- exchanger which are involved in proton secretion; a luminal sodium channel and a contraluminal Na+/K+-AT-Pase for sodium reabsorption; a K+ channel for potassium secretion, and a Na+/K+/Cl- cotransport system for chloride transport and/or volume regulation. The plasma membranes also possess transport systems for organic substrates and organic osmolytes. D-glucose, the main substrate of the papillary collecting duct is taken up into the cell by a sodium-independent D-glucose transport system with a Km of 1.2 mM. The plasma membrane also contains mechanisms which mediate sorbitol release into the medium. This mechanism is stimulated when cells are exposed to media with a low osmolality and inhibited when cells are exposed to media with a high osmolality. D-glucose is used as metabolic substrate in anaerobic and aerobic glycolysis and as precursor for sorbitol synthesis via the aldose reductase, which is highly enriched in papillary collecting duct cells. The cells also show gluconeogenic activity as evidenced by incorporation of labeled carbon from L-alanine into glycerol, sorbitol, and myo-inositol. Accordingly, the cells show fructose-1,6-biphosphatase activity. Sorbitol synthesis in contrast to sorbitol permeability is not affected by osmolarity.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R K Kinne
- Max-Planck-Institut für Systemphysiologie, Dortmund
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30
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Oberhaensli RD, Rajagopalan B, Taylor DJ, Radda GK, Collins JE, Leonard JV, Schwarz H, Herschkowitz N. Study of hereditary fructose intolerance by use of 31P magnetic resonance spectroscopy. Lancet 1987; 2:931-4. [PMID: 2889861 DOI: 10.1016/s0140-6736(87)91419-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of fructose on liver metabolism in patients with hereditary fructose intolerance (HFI) and in heterozygotes for HFI was studied by 31P magnetic resonance spectroscopy (31P-MRS). In patients with HFI (n = 5) ingestion of small amounts of fructose was followed by an increase in sugar phosphates and decrease in inorganic phosphate (Pi) in the liver that could be detected by 31P-MRS. 31P-MRS could be used to diagnose fructose intolerance and to monitor the patients' compliance with a fructose-restricted diet. In heterozygotes (n = 8) 50 g fructose given orally led to accumulation of sugar phosphates and depletion of Pi in the liver. Fructose also induced a larger increase in plasma urate in heterozygotes than in control subjects. The effect of fructose on liver Pi and plasma urate was most pronounced in heterozygotes with gout (n = 3). Heterozygosity for HFI may predispose to hyperuricaemia.
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Affiliation(s)
- R D Oberhaensli
- MRC Clinical Magnetic Resonance Facility, John Radcliffe Hospital, Oxford
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31
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Bastin J, Cambon N, Thompson M, Lowry OH, Burch HB. Change in energy reserves in different segments of the nephron during brief ischemia. Kidney Int 1987; 31:1239-47. [PMID: 3613402 DOI: 10.1038/ki.1987.137] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Rat kidneys were made ischemic for 5 to 120 seconds. Segments of individual nephrons were dissected from freeze dried sections and analyzed for ATP, phosphocreatine, glycogen, glucose, glucose-6-phosphate, lactate and creatine kinase. ATP fell most rapidly in proximal convoluted and straight tubules (PCT, PST) and distal convoluted tubules (DCT), and most slowly in glomerulus and papilla. Phosphocreatine levels ranged fivefold and was highest in DCT, where it approached that of brain. Creatine kinase ranged 100-fold with lowest level in PCT, where the ischemic fall in phosphocreatine was so slow as to suggest a function other than that of an energy reserve. Glycogen varied tenfold from modest levels in distal segments to very low levels in PST, and was not used rapidly in any segment. Glucose consumption and lactate production were most rapid in distal portions. High-energy phosphate consumption for the first 7.5 seconds of ischemia, calculated from these data, indicates roughly-equal energy metabolism in proximal and distal segments, with lower levels in papilla, and especially in glomerulus. The absolute values suggest that the in vivo metabolic rate of the nephron continued almost unabated for 5 or 10 seconds of ischemia.
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32
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MacGregor LC, Rosecan LR, Laties AM, Matschinsky FM. Altered retinal metabolism in diabetes. I. Microanalysis of lipid, glucose, sorbitol, and myo-inositol in the choroid and in the individual layers of the rabbit retina. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)35619-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Sestoft L. An evaluation of biochemical aspects of intravenous fructose, sorbitol and xylitol administration in man. ACTA ANAESTHESIOLOGICA SCANDINAVICA. SUPPLEMENTUM 1985; 82:19-29. [PMID: 3904297 DOI: 10.1111/j.1399-6576.1985.tb02336.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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34
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35
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Dousa TP, Kiebzak GM, Yusufi AN, Kusano E, Braun-Werness J. ATP as a factor in the response of the cAMP system to PTH in proximal and distal convoluted tubules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1984; 178:139-44. [PMID: 6095614 DOI: 10.1007/978-1-4684-4808-5_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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36
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Burch HB, Hays AE, McCreary MD, Cole BR, Chi MM, Dence CN, Lowry OH. Relationships in different parts of the nephron between enzymes of glycerol metabolism and the metabolite changes which result from large glycerol loads. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34833-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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