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Rachubik P, Rogacka D, Audzeyenka I, Typiak M, Wysocka M, Szrejder M, Lesner A, Piwkowska A. Role of lysosomes in insulin signaling and glucose uptake in cultured rat podocytes. Biochem Biophys Res Commun 2023; 679:145-159. [PMID: 37696068 DOI: 10.1016/j.bbrc.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/30/2023] [Accepted: 09/05/2023] [Indexed: 09/13/2023]
Abstract
Podocytes are sensitive to insulin, which governs the functional and structural integrity of podocytes that are essential for proper function of the glomerular filtration barrier. Lysosomes are acidic organelles that are implicated in regulation of the insulin signaling pathway. Cathepsin D (CTPD) and lysosome-associated membrane protein 1 (LAMP1) are major lysosomal proteins that reflect the functional state of lysosomes. However, the effect of insulin on lysosome activity and role of lysosomes in the regulation of insulin-dependent glucose uptake in podocytes are unknown. Our studies showed that the short-term incubation of podocytes with insulin decreased LAMP1 and CTPD mRNA levels. Insulin and bafilomycin A1 reduced both the amounts of LAMP1 and CTPD proteins and activity of CTPD, which were associated with a decrease in the fluorescence intensity of lysosomes that were labeled with LysoTracker. Bafilomycin A1 inhibited insulin-dependent endocytosis of the insulin receptor and increased the amounts of the insulin receptor and glucose transporter 4 on the cell surface of podocytes. Bafilomycin A1 also inhibited insulin-dependent glucose uptake despite an increase in the amount of glucose transporter 4 in the plasma membrane of podocytes. These results suggest that lysosomes are signaling hubs that may be involved in the coupling of insulin signaling with the regulation of glucose uptake in podocytes. The dysregulation of this mechanism can lead to the dysfunction of podocytes and development of insulin resistance.
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Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Marlena Typiak
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59 St, Gdansk, 80-308, Poland.
| | - Magdalena Wysocka
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Adam Lesner
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
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Kulesza T, Typiak M, Rachubik P, Audzeyenka I, Rogacka D, Angielski S, Saleem MA, Piwkowska A. Hyperglycemic environment disrupts phosphate transporter function and promotes calcification processes in podocytes and isolated glomeruli. J Cell Physiol 2022; 237:2478-2491. [PMID: 35150131 DOI: 10.1002/jcp.30700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/20/2022] [Accepted: 02/02/2022] [Indexed: 11/10/2022]
Abstract
Soft tissue calcification is a pathological phenomenon that often occurs in end-stage chronic kidney disease (CKD), which is caused by diabetic nephropathy, among other factors. Hyperphosphatemia present during course of CKD contributes to impairments in kidney function, particularly damages in the glomerular filtration barrier (GFB). Essential elements of the GFB include glomerular epithelial cells, called podocytes. In the present study, we found that human immortalized podocytes express messenger RNA and protein of phosphate transporters, including NaPi 2c (SLC34A3), Pit 1 (SLC20A1), and Pit 2 (SLC20A2), which are sodium-dependent and mediate intracellular phosphate (Pi) transport, and XPR1, which is responsible for extracellular Pi transport. We found that cells that were grown in a medium with a high glucose (HG) concentration (30 mM) expressed less Pit 1 and Pit 2 protein than podocytes that were cultured in a standard glucose medium (11 mM). We found that exposure of the analyzed transporters in the cell membrane of the podocyte is altered by HG conditions. We also found that the activity of tissue nonspecific alkaline phosphatase increased in HG, causing a rise in Pi generation. Additionally, HG led to a reduction of the amount of ectonucleotide pyrophosphatase/phosphodiesterase 1 in the cell membrane of podocytes. The extracellular concentration of pyrophosphate also decreased under HG conditions. These data suggest that a hyperglycemic environment enhances the production of Pi in podocytes and its retention in the extracellular space, which may induce glomerular calcification.
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Affiliation(s)
- Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | | | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
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Szrejder M, Rogacka D, Piwkowska A. Purinergic P2 receptors: Involvement and therapeutic implications in diabetes-related glomerular injury. Arch Biochem Biophys 2021; 714:109078. [PMID: 34742673 DOI: 10.1016/j.abb.2021.109078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/15/2021] [Accepted: 10/30/2021] [Indexed: 02/08/2023]
Abstract
The purinergic activation of P2 receptors initiates a powerful and rapid signaling cascade that contributes to the regulation of an array of physiological and pathophysiological processes in many organs, including the kidney. P2 receptors are broadly distributed in both epithelial and vascular renal cells. Disturbances of purinergic signaling can lead to impairments in renal function. A growing body of evidence indicates changes in P2 receptor expression and nucleotide metabolism in chronic renal injury and inflammatory diseases. Increasing attention has focused on purinergic P2X7 receptors, which are not normally expressed in healthy kidney tissue but are highly expressed at sites of tissue damage and inflammation. Under hyperglycemic conditions, several mechanisms that are linked to purinergic signaling and involve nucleotide release and degradation are disrupted, resulting in the accumulation of adenosine 5'-triphosphate in the bloodstream in diabetes. Dysfunction of the purinergic system might be associated with serious vascular complications in diabetes, including diabetic nephropathy. This review summarizes our current knowledge of the role of P2 receptors in diabetes-related glomerular injury and its implications for new therapeutics for diabetic nephropathy.
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Affiliation(s)
- Maria Szrejder
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland.
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; Department of Molecular Biotechnology, University of Gdańsk, Faculty of Chemistry, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; Department of Molecular Biotechnology, University of Gdańsk, Faculty of Chemistry, Gdańsk, Poland
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Typiak M, Kulesza T, Rachubik P, Rogacka D, Audzeyenka I, Angielski S, Saleem MA, Piwkowska A. Role of Klotho in Hyperglycemia: Its Levels and Effects on Fibroblast Growth Factor Receptors, Glycolysis, and Glomerular Filtration. Int J Mol Sci 2021; 22:7867. [PMID: 34360633 PMCID: PMC8345972 DOI: 10.3390/ijms22157867] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/21/2021] [Accepted: 07/21/2021] [Indexed: 01/14/2023] Open
Abstract
Hyperglycemic conditions (HG), at early stages of diabetic nephropathy (DN), cause a decrease in podocyte numbers and an aberration of their function as key cells for glomerular plasma filtration. Klotho protein was shown to overcome some negative effects of hyperglycemia. Klotho is also a coreceptor for fibroblast growth factor receptors (FGFRs), the signaling of which, together with a proper rate of glycolysis in podocytes, is needed for a proper function of the glomerular filtration barrier. Therefore, we measured levels of Klotho in renal tissue, serum, and urine shortly after DN induction. We investigated whether it influences levels of FGFRs, rates of glycolysis in podocytes, and albumin permeability. During hyperglycemia, the level of membrane-bound Klotho in renal tissue decreased, with an increase in the shedding of soluble Klotho, its higher presence in serum, and lower urinary excretion. The addition of Klotho increased FGFR levels, especially FGFR1/FGFR2, after their HG-induced decrease. Klotho also increased levels of glycolytic parameters of podocytes, and decreased podocytic and glomerular albumin permeability in HG. Thus, we found that the decrease in the urinary excretion of Klotho might be an early biomarker of DN and that Klotho administration may have several beneficial effects on renal function in DN.
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Affiliation(s)
- Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
| | - Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
| | - Moin A. Saleem
- Bristol Renal, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK;
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdansk, Poland; (T.K.); (P.R.); (D.R.); (I.A.); (S.A.); (A.P.)
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland
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Sałaga-Zaleska K, Pikul P, Kreft E, Herman S, Chyła G, Dąbkowski K, Kuchta A, Lenartowicz M, Jankowski M. Effect of suramin on urinary excretion of diabetes-induced glomerular and tubular injury parameters in rats. Biomed Pharmacother 2021; 139:111683. [PMID: 34243631 DOI: 10.1016/j.biopha.2021.111683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 11/18/2022] Open
Abstract
Diabetes mellitus causes changes in metabolism of extracellular nucleotides acting through P2 receptors (P2Rs). This affects renal function and may lead to glomerular and tubular disturbances. We measured urinary excretion of nucleotides (ATP, ADP, AMP, UTP, UDP, UMP) in streptozotocin-induced diabetic rats (65 mg/kg, i.p., day 0) and the effects of P2Rs' blockade by suramin (10 mg/kg, i.p., days +7, +14) on glomerular P2×7R expression and urinary excretion of glomerular (albumin, nephrin) and tubular (KIM-1, NGAL) injury markers, electrolytes, and oxidative stress markers (TBARS, 8-OHdG). Concentrations of nucleotides, specific proteins, electrolytes, and oxidative stress markers in 24-h urine samples collected in metabolic cages at days -1, +6 and +20 were measured using ion-paired reversed-phase HPLC, immunoenzymatic and fluorometric methods, and flame photometry, respectively. Expression of KIM-1 and P2×7R was examined by immunohistochemistry or immunoblotting. Diabetes was associated with increased urinary excretion of ATP, ADP, UTP, UDP and glomerular P2×7R expression. Suramin attenuated P2×7R expression but did not affect urinary excretion of nucleotides. Urinary excretion of albumin, nephrin, NGAL, and 8-OHdG were increased in diabetic rats and were not affected by suramin. TBARS was higher in diabetic rats and suramin attenuated the excretion dynamics in this group. KIM-1 excretion was higher in diabetic rats and suramin further increased excretion of KIM-1 in both diabetic and non-diabetic rats. Furthermore, suramin attenuated the diabetes-induced natriuresis and kaliuresis. It is possible that suramin affects both glomerular and tubular functions in diabetic rats.
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Affiliation(s)
- K Sałaga-Zaleska
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland
| | - P Pikul
- Clinical Laboratory University Clinical Center in Gdansk, 80-211 Gdańsk, Poland
| | - E Kreft
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland
| | - S Herman
- Laboratory of Genetics and Evolutionism, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - G Chyła
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland
| | - K Dąbkowski
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland
| | - A Kuchta
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland
| | - M Lenartowicz
- Laboratory of Genetics and Evolutionism, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - M Jankowski
- Department of Clinical Chemistry, Medical University of Gdansk, Dębinki 7, 80-210, Poland.
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Suramin enhances the urinary excretion of VEGF-A in normoglycemic and streptozotocin-induced diabetic rats. Pharmacol Rep 2021; 73:841-846. [PMID: 33635529 PMCID: PMC8180480 DOI: 10.1007/s43440-021-00236-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 10/24/2022]
Abstract
BACKGROUND Vascular endothelial growth factor A (VEGF-A) and P2-receptors (P2Rs) are involved in the pathogenesis of diabetic nephropathy. The processing of VEGF-A by matrix metalloproteinases (MMP) regulates its bioavailability. Since the ATP-induced release of MMP-9 is mediated by P2Rs, we investigated the effect of suramin on VEGF-A excretion in urine and the urinary activity of total MMP and MMP-9. METHODS The effect of suramin (10 mg/kg, ip) on VEGF-A concentration in serum and its excretion in urine was investigated in streptozotocin (STZ)-induced diabetic rats over a 21-day period. The rats received suramin 7 and 14 days after a single STZ injection (65 mg/kg, ip). A 24-h collection of urine was performed on the day preceding the administration of STZ and the first administration of suramin and on the day before the end of the experiment. The VEGF-A in serum and urine, albumin in urine, and total activity of MMP and MMP-9 in urine were measured using immunoassays. RESULTS Diabetic rats are characterized by a sixfold higher urinary excretion of VEGF-A. Suramin potentiates VEGF-A urinary excretion by 36% (p = 0.046) in non-diabetic and by 75% (p = 0.0322) in diabetic rats but it did not affect VEGF-A concentration in the serum of non-diabetic and diabetic rats. Urinary albumin excretion as well as total MMP and MMP-9 activity was increased in diabetic rats, but these parameters were not affected by suramin. CONCLUSION Suramin increases the urinary excretion of VEGF-A in normoglycemia and hyperglycaemia, possibly without the involvement of MMP-9. Suramin may be used as a pharmacological tool enhancing VEGF-A urinary secretion.
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Extracellular ATP modulates podocyte function through P2Y purinergic receptors and pleiotropic effects on AMPK and cAMP/PKA signaling pathways. Arch Biochem Biophys 2020; 695:108649. [PMID: 33122160 DOI: 10.1016/j.abb.2020.108649] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/25/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023]
Abstract
Podocytes and their foot processes interlinked by slit diaphragms, constitute a continuous outermost layer of the glomerular capillary and seem to be crucial for maintaining the integrity of the glomerular filtration barrier. Purinergic signaling is involved in a wide range of physiological processes in the renal system, including regulating glomerular filtration. We evaluated the role of nucleotide receptors in cultured rat podocytes using non-selective P2 receptor agonists and agonists specific for the P2Y1, P2Y2, and P2Y4 receptors. The results showed that extracellular ATP evokes cAMP-dependent pathways through P2 receptors and influences remodeling of the podocyte cytoskeleton and podocyte permeability to albumin via coupling with RhoA signaling. Our findings highlight the relevance of the P2Y4 receptor in protein kinase A-mediated signal transduction to the actin cytoskeleton. We observed increased cAMP concentration and decreased RhoA activity after treatment with a P2Y4 agonist. Moreover, protein kinase A inhibitors reversed P2Y4-induced changes in RhoA activity and intracellular F-actin staining. P2Y4 stimulation resulted in enhanced AMPK phosphorylation and reduced reactive oxygen species generation. Our findings identify P2Y-PKA-RhoA signaling as the regulatory mechanism of the podocyte contractile apparatus and glomerular filtration. We describe a protection mechanism for the glomerular barrier linked to reduced oxidative stress and reestablished energy balance.
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Vallon V, Unwin R, Inscho EW, Leipziger J, Kishore BK. Extracellular Nucleotides and P2 Receptors in Renal Function. Physiol Rev 2019; 100:211-269. [PMID: 31437091 DOI: 10.1152/physrev.00038.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The understanding of the nucleotide/P2 receptor system in the regulation of renal hemodynamics and transport function has grown exponentially over the last 20 yr. This review attempts to integrate the available data while also identifying areas of missing information. First, the determinants of nucleotide concentrations in the interstitial and tubular fluids of the kidney are described, including mechanisms of cellular release of nucleotides and their extracellular breakdown. Then the renal cell membrane expression of P2X and P2Y receptors is discussed in the context of their effects on renal vascular and tubular functions. Attention is paid to effects on the cortical vasculature and intraglomerular structures, autoregulation of renal blood flow, tubuloglomerular feedback, and the control of medullary blood flow. The role of the nucleotide/P2 receptor system in the autocrine/paracrine regulation of sodium and fluid transport in the tubular and collecting duct system is outlined together with its role in integrative sodium and fluid homeostasis and blood pressure control. The final section summarizes the rapidly growing evidence indicating a prominent role of the extracellular nucleotide/P2 receptor system in the pathophysiology of the kidney and aims to identify potential therapeutic opportunities, including hypertension, lithium-induced nephropathy, polycystic kidney disease, and kidney inflammation. We are only beginning to unravel the distinct physiological and pathophysiological influences of the extracellular nucleotide/P2 receptor system and the associated therapeutic perspectives.
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Affiliation(s)
- Volker Vallon
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Robert Unwin
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Edward W Inscho
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Jens Leipziger
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Bellamkonda K Kishore
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
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Impact of ET-1 and sex in glomerular hyperfiltration in humanized sickle cell mice. Clin Sci (Lond) 2019; 133:1475-1486. [PMID: 31273050 DOI: 10.1042/cs20190215] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 02/07/2023]
Abstract
Hyperfiltration, highly prevalent early in sickle cell disease (SCD), is in part driven by an increase in ultrafiltration coefficient (Kf). The increase in Kf may be due to enlarged filtration surface area and/or increased glomerular permeability (Palb). Previous studies have demonstrated that endothelin-1 (ET-1) contributes to Palb changes in models of diabetes and SCD. Thus, we performed longitudinal studies of renal function to determine the relationship between ET-1 and glomerular size and Palb that may contribute to hyperfiltration in humanized sickle cell (HbSS) and control (HbAA) mice at 8-32 weeks of age. HbSS mice were characterized by significant increases in plasma and glomerular ET-1 expression in both sexes although this increase was significantly greater in males. HbSS glomeruli of both males and females presented with a progressive and significant increase in glomerular size, volume, and Kf During the onset of hyperfiltration, plasma and glomerular ET-1 expression were associated with a greater increase in glomerular size and Kf in HbSS mice, regardless of sex. The pattern of Palb augmentation during the hyperfiltration was also associated with an increase in glomerular ET-1 expression, in both male and female HbSS mice. However, the increase in Palb was significantly greater in males and delayed in time in females. Additionally, selective endothelin A receptor (ETA) antagonist prevented hyperfiltration in HbSS, regardless of sex. These results suggest that marked sex disparity in glomerular hyperfiltration may be driven, in part, by ET-1-dependent ultra-structural changes in filtration barrier components contributing to glomerular hyperfiltration in HbSS mice.
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De Miguel C, Sedaka R, Kasztan M, Lever JM, Sonnenberger M, Abad A, Jin C, Carmines PK, Pollock DM, Pollock JS. Tauroursodeoxycholic acid (TUDCA) abolishes chronic high salt-induced renal injury and inflammation. Acta Physiol (Oxf) 2019; 226:e13227. [PMID: 30501003 DOI: 10.1111/apha.13227] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 10/23/2018] [Accepted: 11/22/2018] [Indexed: 12/23/2022]
Abstract
AIM Chronic high salt intake exaggerates renal injury and inflammation, especially with the loss of functional ETB receptors. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone and bile salt that is approved for the treatment of hepatic diseases. Our aim was to determine whether TUDCA is reno-protective in a model of ETB receptor deficiency with chronic high salt-induced renal injury and inflammation. METHODS ETB -deficient and transgenic control rats were placed on normal (0.8% NaCl) or high salt (8% NaCl) diet for 3 weeks, receiving TUDCA (400 mg/kg/d; ip) or vehicle. Histological and biochemical markers of kidney injury, renal cell death and renal inflammation were assessed. RESULTS In ETB -deficient rats, high salt diet significantly increased glomerular and proximal tubular histological injury, proteinuria, albuminuria, excretion of tubular injury markers KIM-1 and NGAL, renal cortical cell death and renal CD4+ T cell numbers. TUDCA treatment increased proximal tubule megalin expression as well as prevented high salt diet-induced glomerular and tubular damage in ETB -deficient rats, as indicated by reduced kidney injury markers, decreased glomerular permeability and proximal tubule brush border restoration, as well as reduced renal inflammation. However, TUDCA had no significant effect on blood pressure. CONCLUSIONS TUDCA protects against the development of glomerular and proximal tubular damage, decreases renal cell death and inflammation in the renal cortex in rats with ETB receptor dysfunction on a chronic high salt diet. These results highlight the potential use of TUDCA as a preventive tool against chronic high salt induced renal damage.
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Affiliation(s)
- Carmen De Miguel
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Randee Sedaka
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Malgorzata Kasztan
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Jeremie M. Lever
- Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Michelle Sonnenberger
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Andrew Abad
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Chunhua Jin
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Pamela K. Carmines
- Department of Cellular and Integrative Physiology University of Nebraska Medical Center Omaha Nebraska
| | - David M. Pollock
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Jennifer S. Pollock
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
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11
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Horenstein AL, Bracci C, Morandi F, Malavasi F. CD38 in Adenosinergic Pathways and Metabolic Re-programming in Human Multiple Myeloma Cells: In-tandem Insights From Basic Science to Therapy. Front Immunol 2019; 10:760. [PMID: 31068926 PMCID: PMC6491463 DOI: 10.3389/fimmu.2019.00760] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/21/2019] [Indexed: 01/10/2023] Open
Abstract
Tumor microenvironments are rich in extracellular nucleotides that can be metabolized by ectoenzymes to produce adenosine, a nucleoside involved in controlling immune responses. Multiple myeloma, a plasma cell malignancy developed within a bone marrow niche, exploits adenosinergic pathways to customize the immune homeostasis of the tumor. CD38, a multifunctional protein that acts as both receptor and ectoenzyme, is overexpressed at all stages of myeloma. At neutral and acidic pH, CD38 catalyzes the extracellular conversion of NAD+ to regulators of calcium signaling. The initial disassembly of NAD+ is also followed by adenosinergic activity, if CD38 is operating in the presence of CD203a and CD73 nucleotidases. cAMP extruded from tumor cells provides another substrate for metabolizing nucleotidases to signaling adenosine. These pathways flank or bypass the canonical adenosinergic pathway subjected to the conversion of ATP by CD39. All of the adenosinergic networks can be hijacked by the tumor, thus controlling the homeostatic reprogramming of the myeloma in the bone marrow. In this context, adenosine assumes the role of a local hormone: cell metabolism is adjusted via low- or high-affinity purinergic receptors expressed by immune and bone cells as well as by tumor cells. The result is immunosuppression, which contributes to the failure of immune surveillance in cancer. A similar metabolic strategy silences immune effectors during the progression of indolent gammopathies to symptomatic overt multiple myeloma disease. Plasma from myeloma aspirates contains elevated levels of adenosine resulting from interactions between myeloma and other cells lining the niche and adenosine concentrations are known to increase as the disease progresses. This is statistically reflected in the International Staging System for multiple myeloma. Along with the ability to deplete CD38+ malignant plasma cell populations which has led to their widespread therapeutic use, anti-CD38 antibodies are involved in the polarization and release of microvesicles characterized by the expression of multiple adenosine-producing molecules. These adenosinergic pathways provide new immune checkpoints for improving immunotherapy protocols by helping to restore the depressed immune response.
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Affiliation(s)
- Alberto L Horenstein
- Laboratory of Immunogenetics, Department of Medical Sciences, Turin, Italy.,CeRMS, University of Torino, Turin, Italy
| | - Cristiano Bracci
- Laboratory of Immunogenetics, Department of Medical Sciences, Turin, Italy.,CeRMS, University of Torino, Turin, Italy
| | - Fabio Morandi
- Stem Cell Laboratory and Cell Therapy Center, Istituto Giannina Gaslini, Genova, Italy
| | - Fabio Malavasi
- Laboratory of Immunogenetics, Department of Medical Sciences, Turin, Italy.,CeRMS, University of Torino, Turin, Italy
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12
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Packer M. Augmentation of glucagon-like peptide-1 receptor signalling by neprilysin inhibition: potential implications for patients with heart failure. Eur J Heart Fail 2018; 20:973-977. [PMID: 29603541 DOI: 10.1002/ejhf.1185] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/23/2018] [Accepted: 02/26/2018] [Indexed: 01/18/2023] Open
Abstract
Augmentation of glucagon-like peptide-1 (GLP-1) receptor signalling is an established approach to the treatment of type 2 diabetes. However, endogenous GLP-1 and long-acting GLP-1 receptor analogues are degraded not only by dipeptidyl peptidase-4, but also by neprilysin. This observation raises the possibilities that endogenous GLP-1 contributes to the clinical effects of neprilysin inhibition and that patients concurrently treated with sacubitril/valsartan and incretin-based drugs may experience important drug-drug interactions. Specifically, potentiation of GLP-1 receptor signalling may underlie the antihyperglycaemic actions of sacubitril/valsartan. Neprilysin inhibitors may also be able to augment the effects of long-acting GLP-1 analogues to increase heart rate and myocardial cyclic AMP, and thus, potentiate these deleterious actions; if so, concomitant treatment with GLP-1 receptor agonists may limit the efficacy of neprilysin inhibitors in patients with both heart failure and diabetes. For patients not concurrently treated with GLP-1 analogues, the action of neprilysin to enhance the effects of GLP-1 may be particularly relevant in the brain, where augmentation of GLP-1 and other endogenous peptides may act to inhibit amyloid-induced neuroinflammation and cytotoxicity and improve memory formation and executive functioning. Experimentally, neprilysin inhibitors may also potentiate the effects of endogenous GLP-1 and GLP-1 receptor agonists on blood vessels and the kidney. The role of neprilysin in the metabolism of endogenous GLP-1 and long-acting GLP-1 analogues points to a range of potential pathophysiological effects that may be clinically relevant to patients with heart failure, with or without diabetes.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX, USA
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13
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Abstract
Globally, diabetes is the leading cause of chronic kidney disease and end-stage renal disease, which are major risk factors for cardiovascular disease and death. Despite this burden, the factors that precipitate the development and progression of diabetic kidney disease (DKD) remain to be fully elucidated. Mitochondrial dysfunction is associated with kidney disease in nondiabetic contexts, and increasing evidence suggests that dysfunctional renal mitochondria are pathological mediators of DKD. These complex organelles have a broad range of functions, including the generation of ATP. The kidneys are mitochondrially rich, highly metabolic organs that require vast amounts of ATP for their normal function. The delivery of metabolic substrates for ATP production, such as fatty acids and oxygen, is altered by diabetes. Changes in metabolic fuel sources in diabetes to meet ATP demands result in increased oxygen consumption, which contributes to renal hypoxia. Inherited factors including mutations in genes that impact mitochondrial function and/or substrate delivery may also be important risk factors for DKD. Hence, we postulate that the diabetic milieu and inherited factors that underlie abnormalities in mitochondrial function synergistically drive the development and progression of DKD.
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Affiliation(s)
- Josephine M Forbes
- Glycation and Diabetes Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, Australia.,Mater Clinical School, School of Medicine, The University of Queensland, St Lucia, Queensland, Australia.,Departments of Medicine and Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - David R Thorburn
- Departments of Medicine and Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
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14
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Palygin O, Ilatovskaya DV, Levchenko V, Endres BT, Geurts AM, Staruschenko A. Nitric oxide production by glomerular podocytes. Nitric Oxide 2017; 72:24-31. [PMID: 29128399 DOI: 10.1016/j.niox.2017.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 09/27/2017] [Accepted: 11/07/2017] [Indexed: 01/18/2023]
Abstract
Nitric Oxide (NO), a potent vasodilator and vital signaling molecule, has been shown to contribute to the regulation of glomerular ultrafiltration. However, whether changes in NO occur in podocytes during the pathogenesis of salt-sensitive hypertension has not yet been thoroughly examined. We showed here that podocytes produce NO, and further hypothesized that hypertensive animals would exhibit reduced NO production in these cells in response to various paracrine factors, which might contribute to the damage of glomeruli filtration barrier and development of proteinuria. To test this, we isolated glomeruli from the kidneys of Dahl salt-sensitive (SS) rats fed a low salt (LS; 0.4% NaCl) or high salt (HS; 4% NaCl, 3 weeks) diets and loaded podocytes with either a combination of NO and Ca2+ fluorophores (DAF-FM and Fura Red, respectively) or DAF-FM alone. Changes in fluorescence were observed with confocal microscopy in response to adenosine triphosphate (ATP), angiotensin II (Ang II), and hydrogen peroxide (H2O2). Application of Ang II resulted in activation of both NO and intracellular calcium ([Ca2+]i) transients. In contrast, ATP promoted [Ca2+]i transients, but did not have any effects on NO production. SS rats fed a HS diet for 3 weeks demonstrated impaired NO production: the response to Ang II or H2O2 in podocytes of glomeruli isolated from SS rats fed a HS diet was significantly reduced compared to rats fed a LS diet. Therefore, glomerular podocytes from hypertensive rats showed a diminished NO release in response to Ang II or oxidative stress, suggesting that podocytic NO signaling is dysfunctional in this condition and likely contributes to the development of kidney injury.
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Affiliation(s)
- Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Bradley T Endres
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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15
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Kasztan M, Fox BM, Speed JS, De Miguel C, Gohar EY, Townes TM, Kutlar A, Pollock JS, Pollock DM. Long-Term Endothelin-A Receptor Antagonism Provides Robust Renal Protection in Humanized Sickle Cell Disease Mice. J Am Soc Nephrol 2017; 28:2443-2458. [PMID: 28348063 DOI: 10.1681/asn.2016070711] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 02/13/2017] [Indexed: 11/03/2022] Open
Abstract
Sickle cell disease (SCD)-associated nephropathy is a major source of morbidity and mortality in patients because of the lack of efficacious treatments targeting renal manifestations of the disease. Here, we describe a long-term treatment strategy with the selective endothelin-A receptor (ETA) antagonist, ambrisentan, designed to interfere with the development of nephropathy in a humanized mouse model of SCD. Ambrisentan preserved GFR at the level of nondisease controls and prevented the development of proteinuria, albuminuria, and nephrinuria. Microscopy studies demonstrated prevention of podocyte loss and structural alterations, the absence of vascular congestion, and attenuation of glomerulosclerosis in treated mice. Studies in isolated glomeruli showed that treatment reduced inflammation and oxidative stress. At the level of renal tubules, ambrisentan treatment prevented the increased excretion of urinary tubular injury biomarkers. Additionally, the treatment strategy prevented tubular brush border loss, diminished tubular iron deposition, blocked the development of interstitial fibrosis, and prevented immune cell infiltration. Furthermore, the prevention of albuminuria in treated mice was associated with preservation of cortical megalin expression. In a separate series of identical experiments, combined ETA and ETB receptor antagonism provided only some of the protection observed with ambrisentan, highlighting the importance of exclusively targeting the ETA receptor in SCD. Our results demonstrate that ambrisentan treatment provides robust protection from diverse renal pathologies in SCD mice, and suggest that long-term ETA receptor antagonism may provide a strategy for the prevention of renal complications of SCD.
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Affiliation(s)
| | - Brandon M Fox
- Cardio-Renal Physiology and Medicine, Department of Medicine, and
| | - Joshua S Speed
- Cardio-Renal Physiology and Medicine, Department of Medicine, and
| | - Carmen De Miguel
- Cardio-Renal Physiology and Medicine, Department of Medicine, and
| | - Eman Y Gohar
- Cardio-Renal Physiology and Medicine, Department of Medicine, and
| | - Tim M Townes
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama; and
| | | | - Jennifer S Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, and.,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, and .,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia
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16
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Castrop H, Schießl IM. Novel routes of albumin passage across the glomerular filtration barrier. Acta Physiol (Oxf) 2017; 219:544-553. [PMID: 27452481 DOI: 10.1111/apha.12760] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/13/2016] [Accepted: 07/20/2016] [Indexed: 12/20/2022]
Abstract
Albuminuria is a hallmark of kidney diseases of various aetiologies and an unambiguous symptom of the compromised integrity of the glomerular filtration barrier. Furthermore, there is increasing evidence that albuminuria per se aggravates the development and progression of chronic kidney disease. This review covers new aspects of the movement of large plasma proteins across the glomerular filtration barrier in health and disease. Specifically, this review focuses on the role of endocytosis and transcytosis of albumin by podocytes, which constitutes a new pathway of plasma proteins across the filtration barrier. Thus, we summarize what is known about the mechanisms of albumin endocytosis by podocytes and address the fate of the endocytosed albumin, which is directed to lysosomal degradation or transcellular movement with subsequent vesicular release into the urinary space. We also address the functional consequences of overt albumin endocytosis by podocytes, such as the formation of pro-inflammatory cytokines, which might eventually result in a deterioration of podocyte function. Finally, we consider the diagnostic potential of podocyte-derived albumin-containing vesicles in the urine as an early marker of a compromised glomerular barrier function. In terms of new technical approaches, the review covers how our knowledge of the movement of albumin across the glomerular filtration barrier has expanded by the use of new intravital imaging techniques.
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Affiliation(s)
- H. Castrop
- Institute of Physiology; University of Regensburg; Regensburg Germany
| | - I. M. Schießl
- Institute of Physiology; University of Regensburg; Regensburg Germany
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17
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Ilatovskaya DV, Palygin O, Staruschenko A. Functional and therapeutic importance of purinergic signaling in polycystic kidney disease. Am J Physiol Renal Physiol 2016; 311:F1135-F1139. [PMID: 27654892 DOI: 10.1152/ajprenal.00406.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/20/2016] [Indexed: 12/12/2022] Open
Abstract
Polycystic kidney diseases (PKD) are a group of inherited nephropathies marked with the formation of fluid-filled cysts along the nephron. This renal disorder affects millions of people worldwide, but current treatment strategies are unfortunately limited to supportive therapy, dietary restrictions, and, eventually, renal transplantation. Recent advances in PKD management are aimed at targeting exaggerated cell proliferation and dedifferentiation to interfere with cyst growth. However, not nearly enough is known about the ion transport properties of the cystic cells, or specific signaling pathways modulating channels and transporters in this condition. There is growing evidence that abnormally elevated concentrations of adenosine triphosphate (ATP) in PKD may contribute to cyst enlargement; change in the profile of purinergic receptors may also result in promotion of cystogenesis. The current mini-review is focused on the role of ATP and associated signaling affecting ion transport properties of the renal cystic epithelia.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
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18
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Peired AJ, Bitzer M. Albumin: innocent bystander or culprit? Am J Physiol Renal Physiol 2016; 311:F409-10. [PMID: 27306981 DOI: 10.1152/ajprenal.00317.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/08/2016] [Indexed: 11/22/2022] Open
Affiliation(s)
- Anna J Peired
- Excellence Centre for Research, Transfer and High Education for the Development of De Novo Therapies, Florence, Italy; Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy; and
| | - Markus Bitzer
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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