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Zhang L, Wu M, Zhang J, Liu T, Fu S, Wang Y, Xu Z. The pivotal role of glucose transporter 1 in diabetic kidney disease. Life Sci 2024; 353:122932. [PMID: 39067659 DOI: 10.1016/j.lfs.2024.122932] [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: 04/05/2024] [Revised: 07/12/2024] [Accepted: 07/20/2024] [Indexed: 07/30/2024]
Abstract
Diabetes mellitus (DM) is a significant public health problem. Diabetic kidney disease (DKD) is the most common complication of DM, and its incidence has been increasing with the increasing prevalence of DM. Given the association between DKD and mortality in patients with DM, DKD is a significant burden on public health resources. Despite its significance in DM progression, the pathogenesis of DKD remains unclear. Aberrant glucose uptake by cells is an important pathophysiological mechanism underlying DKD renal injury. Glucose is transported across the bilayer cell membrane by a glucose transporter (GLUT) located on the cell membrane. Multiple GLUT proteins have been identified in the kidney, and GLUT1 is one of the most abundantly expressed isoforms. GLUT1 is a crucial regulator of intracellular glucose metabolism and plays a key pathological role in the phenotypic changes in DKD mesangial cells. In an attempt to understand the pathogenesis of DKD better, we here present a review of studies on the role of GLUT1 in the development and progression of DKD.
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Affiliation(s)
- Li Zhang
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Meiyan Wu
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Jizhou Zhang
- Department of Biochemistry, College of Basic Medical Sciences, Jilin University, Changchun 130021, China
| | - Tingting Liu
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Shaojie Fu
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Yue Wang
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Zhonggao Xu
- Department of Nephrology, The First Hospital of Jilin University, Changchun, 130021, China.
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2
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Żołnierkiewicz O, Rogacka D. Hyperglycemia - A culprit of podocyte pathology in the context of glycogen metabolism. Arch Biochem Biophys 2024; 753:109927. [PMID: 38350532 DOI: 10.1016/j.abb.2024.109927] [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: 10/26/2023] [Revised: 01/31/2024] [Accepted: 02/10/2024] [Indexed: 02/15/2024]
Abstract
Prolonged disruption in the balance of glucose can result in metabolic disorders. The kidneys play a significant role in regulating blood glucose levels. However, when exposed to chronic hyperglycemia, the kidneys' ability to handle glucose metabolism may be impaired, leading to an accumulation of glycogen. Earlier studies have shown that there can be a significant increase in glucose storage in the form of glycogen in the kidneys in diabetes. Podocytes play a crucial role in maintaining the integrity of filtration barrier. In diabetes, exposure to elevated glucose levels can lead to significant metabolic and structural changes in podocytes, contributing to kidney damage and the development of diabetic kidney disease. The accumulation of glycogen in podocytes is not a well-established phenomenon. However, a recent study has demonstrated the presence of glycogen granules in podocytes. This review delves into the intricate connections between hyperglycemia and glycogen metabolism within the context of the kidney, with special emphasis on podocytes. The aberrant storage of glycogen has the potential to detrimentally impact podocyte functionality and perturb their structural integrity. This review provides a comprehensive analysis of the alterations in cellular signaling pathways that may potentially lead to glycogen overproduction in podocytes.
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Affiliation(s)
- Olga Żołnierkiewicz
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
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3
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Guo C, He J, Deng X, Wang D, Yuan G. Potential therapeutic value of melatonin in diabetic nephropathy: improvement beyond anti-oxidative stress. Arch Physiol Biochem 2023; 129:1250-1261. [PMID: 34048666 DOI: 10.1080/13813455.2021.1933539] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 05/18/2021] [Indexed: 12/23/2022]
Abstract
Diabetic nephropathy (DN) is a common complication of diabetes, and it is also the main cause of chronic renal failure. Physiological/pathological changes mediated by high glucose are the main factors causing injury of DN, including the enhancement of polyol pathway, the accumulation of advanced glycation products (AGEs), and the activation of protein kinase C (PKC) and transforming growth factor-β (TGF-β) signals. In addition, the abnormal activation of renin-angiotensin system (RAS) and oxidative stress are also involved. Melatonin is a physiological hormone mainly secreted by the pineal gland which has been proved to be related to diabetes. Studies have shown that exogenous melatonin intervention can reduce blood glucose and alleviate high glucose mediated pathological damage. At the same time, melatonin also has a strong antioxidant effect, and can inhibit the activation of RAS. Therefore, it is of great significance to explore the therapeutic effect and value of melatonin on DN.
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Affiliation(s)
- Chang Guo
- Department of Nephrology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Jianqiang He
- Department of Nephrology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Xia Deng
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Dong Wang
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
| | - Guoyue Yuan
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, China
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4
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Rogacka D, Rachubik P, Audzeyenka I, Kulesza T, Szrejder M, Myślińska D, Angielski S, Piwkowska A. Inhibition of phosphodiesterase 5A by tadalafil improves SIRT1 expression and activity in insulin-resistant podocytes. Cell Signal 2023; 105:110622. [PMID: 36754339 DOI: 10.1016/j.cellsig.2023.110622] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/13/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023]
Abstract
A decrease in intracellular levels of 3',5'-cyclic guanosine monophosphate (cGMP) has been implicated in the progression of diabetic nephropathy. Hyperglycemia significantly inhibits cGMP-dependent pathway activity in the kidney, leading to glomerular damage and proteinuria. The enhancement of activity of this pathway that is associated with an elevation of cGMP levels may be achieved by inhibition of the cGMP specific phosphodiesterase 5A (PDE5A) using selective inhibitors, such as tadalafil. Hyperglycemia decreased the insulin responsiveness of podocytes and impaired podocyte function. These effects were associated with lower protein amounts and activity of the protein deacetylase sirtuin 1 (SIRT1) and a decrease in the phosphorylation of adenosine monophosphate-dependent protein kinase (AMPK). We found that PDE5A protein levels increased in hyperglycemia, and PDE5A downregulation improved the insulin responsiveness of podocytes with reestablished SIRT1 expression and activity. PDE5A inhibitors potentiate nitric oxide (NO)/cGMP signaling, and NO modulates the activity and expression of SIRT1. Therefore, we investigated the effects of tadalafil on SIRT1 and AMPK in the context of improving the insulin sensitivity in podocytes and podocyte function in hyperglycemia. Our study revealed that tadalafil restored SIRT1 expression and activity and activated AMPK by increasing its phosphorylation. Tadalafil also restored stimulating effect of insulin on glucose transport in podocytes with high glucose-induced insulin resistance. Additionally, tadalafil improved the function of podocytes that were exposed to high glucose concentrations. Our results display novel mechanisms involved in the pathogenesis of glomerulopathies in diabetes, which may contribute to the development of more effective treatment strategies for diabetic nephropathy.
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Affiliation(s)
- Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Dorota Myślińska
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, Gdansk 80-308, Poland.
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland.
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland.
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5
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Szrejder M, Typiak M, Pikul P, Audzeyenka I, Rachubik P, Rogacka D, Narajczyk M, Piwkowska A. Role of L-lactate as an energy substrate in primary rat podocytes under physiological and glucose deprivation conditions. Eur J Cell Biol 2023; 102:151298. [PMID: 36805821 DOI: 10.1016/j.ejcb.2023.151298] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
Lactate has long been acknowledged to be a metabolic waste product, but it has more recently been found as a fuel energy source in mammalian cells. Podocytes are an important component of the glomerular filter, and their role in maintaining the structural integrity of this structure was established. These cells rely on a constant energy supply and reservoir. The utilization of alternative energy substrates to preserve energetic homeostasis is a subject of extensive research, and lactate appears to be one such candidate. Therefore, we investigated the role of lactate as an energy substrate and characterize the lactate transport system in cultured rat podocytes during sufficient and insufficient glucose supplies. The present study, for the first time, demonstrated the presence of lactate transporters in podocytes. Moreover, we observed modified the amount of these transporters in response to limited glucose availability and after l-lactate supplementation. Simultaneously, exposure to l-lactate preserved cell survival during insufficient glucose supply. Interestingly, during glucose deprivation, lactate exposure allowed the steady flow of glycolysis and prevented glycogen reserves depletion. Summarizing, podocytes utilize lactate as an energy substrate and possess a developed system that controls lactate homeostasis, suggesting that it plays an essential role in podocyte metabolism, especially during fluctuations of energy availability.
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Affiliation(s)
- Maria Szrejder
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland.
| | - Marlena Typiak
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdansk, Faculty of Biology, Gdansk, Poland
| | - Piotr Pikul
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Irena Audzeyenka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdansk, Faculty of Chemistry, Gdańsk, Poland
| | - Patrycja Rachubik
- 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; University of Gdansk, Faculty of Chemistry, Gdańsk, Poland
| | | | - Agnieszka Piwkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdansk, Faculty of Chemistry, Gdańsk, Poland
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Zha D, Wu X. Nutrient sensing, signaling transduction, and autophagy in podocyte injury: implications for kidney disease. J Nephrol 2023; 36:17-29. [PMID: 35704261 DOI: 10.1007/s40620-022-01365-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/05/2022] [Indexed: 02/07/2023]
Abstract
Podocytes are terminally differentiated epithelial cells of the renal glomerular tuft and these highly specialized cells are essential for the integrity of the slit diaphragm. The biological function of podocytes is primarily based on a complex ramified structure that requires sufficient nutrients and a large supply of energy in support of their unique structure and function in the glomeruli. Of note, the dysregulation of nutrient signaling and energy metabolic pathways in podocytes has been associated with a range of kidney diseases i.e., diabetic nephropathy. Therefore, nutrient-related and energy metabolic signaling pathways are critical to maintaining podocyte homeostasis and the pathogenesis of podocyte injury. Recently, a growing body of evidence has indicated that nutrient starvation induces autophagy, which suggests crosstalk between nutritional signaling with the modulation of autophagy for podocytes to adapt to nutrient deprivation. In this review, the current knowledge and advancement in the understanding of nutrient sensing, signaling, and autophagy in the podocyte biology, injury, and pathogenesis of kidney diseases is summarized. Based on the existing findings, the implications and perspective to target these signaling pathways and autophagy in podocytes during the development of novel preventive and therapeutic strategies in patients with podocyte injury-associated kidney diseases are discussed.
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Affiliation(s)
- Dongqing Zha
- Division of Nephrology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430070, Hubei, China
| | - Xiaoyan Wu
- Division of Nephrology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430070, Hubei, China.
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Rogacka D, Rachubik P, Audzeyenka I, Szrejder M, Kulesza T, Myślińska D, Angielski S, Piwkowska A. Enhancement of cGMP-dependent pathway activity ameliorates hyperglycemia-induced decrease in SIRT1-AMPK activity in podocytes: Impact on glucose uptake and podocyte function. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119362. [PMID: 36152759 DOI: 10.1016/j.bbamcr.2022.119362] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/01/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Hyperglycemia significantly decreases 3',5'-cyclic guanosine monophosphate (cGMP)-dependent pathway activity in the kidney. A well-characterized downstream signaling effector of cGMP is cGMP-dependent protein kinase G (PKG), exerting a wide range of downstream effects, including vasodilation and vascular smooth muscle cells relaxation. In podocytes that are exposed to high glucose concentrations, crosstalk between the protein deacetylase sirtuin 1 (SIRT1) and adenosine monophosphate-dependent protein kinase (AMPK) decreased, attenuating insulin responsiveness and impairing podocyte function. The present study examined the effect of enhancing cGMP-dependent pathway activity on SIRT1-AMPK crosstalk in podocytes under hyperglycemic conditions. We found that enhancing cGMP-dependent pathway activity using a cGMP analog was associated with increases in SIRT1 protein levels and activity, with a concomitant increase in the degree of AMPK phosphorylation. The beneficial effects of enhancing cGMP-dependent pathway activity on SIRT1-AMPK crosstalk also included improvements in podocyte function. Based on our findings, we postulate an important role for SIRT1-AMPK crosstalk in the regulation of albumin permeability in hyperglycemia that is strongly associated with activity of the cGMP-dependent pathway.
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Affiliation(s)
- 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.
| | - 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
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Dorota Myślińska
- Department of Animal and Human Physiology, Faculty of Biology, 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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Mindukshev I, Fock E, Dobrylko I, Sudnitsyna J, Gambaryan S, Panteleev MA. Platelet Hemostasis Reactions at Different Temperatures Correlate with Intracellular Calcium Concentration. Int J Mol Sci 2022; 23:ijms231810667. [PMID: 36142580 PMCID: PMC9505593 DOI: 10.3390/ijms231810667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/05/2022] [Accepted: 09/05/2022] [Indexed: 11/22/2022] Open
Abstract
Hypo- and hyperthermia affect both primary and secondary hemostasis; however, there are controversial data concerning platelet activation and the underlying mechanisms under hypo- and hyperthermia. The discrepancies in the data could be partly explained by different approaches to hemostatic reactions analysis. We applied a new LaSca-TMF laser particle analyzer for a simultaneous fluorescence and laser scattering analysis of platelet responses at different temperatures. Human platelets were activated by ADP in a wide range of temperatures, and platelet transformations (e.g., a shape change reaction, aggregation and clot formation) and the intracellular calcium concentration ([Ca2+]i) were analyzed by LaSca-TMF and confocal microscopy. The platelet shape change reaction gradually increased with a rising temperature. The platelet aggregation strongly decreased at low ADP concentrations with the augmentation of the temperature and was independent of the temperature at high ADP concentrations. In contrast, the clotting time decreased with a temperature increase. Similar to the aggregation response, a rise in [Ca2+]i triggered by low ADP concentrations was higher under hypothermic conditions and the differences were independent of the temperature at high ADP concentrations. We showed that the key reactions of cellular hemostasis are differentially regulated by temperature and demonstrated for the first time that an accelerated aggregation under hypothermic conditions directly correlated with an increased level in [Ca2+]i in platelets.
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Affiliation(s)
- Igor Mindukshev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Ave., 194223 Saint Petersburg, Russia
| | - Ekaterina Fock
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Ave., 194223 Saint Petersburg, Russia
| | - Irina Dobrylko
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Ave., 194223 Saint Petersburg, Russia
| | - Julia Sudnitsyna
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Ave., 194223 Saint Petersburg, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya St., 109029 Moscow, Russia
| | - Stepan Gambaryan
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 44 Thorez Ave., 194223 Saint Petersburg, Russia
- Correspondence: (S.G.); (M.A.P.)
| | - Mikhail A. Panteleev
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya St., 109029 Moscow, Russia
- Correspondence: (S.G.); (M.A.P.)
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Sinha S, Haque M. Insulin Resistance and Type 2 Diabetes Mellitus: An Ultimatum to Renal Physiology. Cureus 2022; 14:e28944. [PMID: 36111327 PMCID: PMC9462660 DOI: 10.7759/cureus.28944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2022] [Indexed: 11/24/2022] Open
Abstract
Insulin resistance (IR) is stated as diminished insulin action regardless of hyperinsulinemia. The usual target organs for insulin activities are the liver, skeletal muscle, and adipose tissue. Hence, the vasculature and kidneys are nonconventional target organs as the impacts of insulin on these are comparatively separate from other conventional target organs. Vasodilation is achieved by raising endothelial nitric oxide (NO) generation by initiating the phosphoinositide 3-kinase (PI3K) pathway. In insulin-nonresponsive conditions, this process is defective, and there is increased production of endothelin-1 through the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway, which predominates the NO effects, causing vasoconstriction. Renal tubular cells and podocytes have insulin receptors, and their purposeful importance has been studied, which discloses critical acts of insulin signaling in podocyte survivability and tubular action. Diabetic nephropathy (DN) is a prevalent problem in individuals with hypertension, poor glycemic management, hereditary susceptibility, or glomerular hyperfiltration. DN could be a significant contributing factor to end-stage renal disease (ESRD) that results from chronic kidney disease (CKD). IR and diabetes mellitus (DM) are the constituents of syndrome X and are accompanied by CKD progression. IR performs a key part in syndrome X leading to CKD. However, it is indistinct whether IR individually participates in enhancing the threat to CKD advancement rather than CKD complexity. CKD is an extensive public health problem affecting millions of individuals worldwide. The tremendous spread of kidney disease intensifies people’s health impacts related to communicable and noncommunicable diseases. Chronic disease regulator policies do not include CKD at global, local, and/or general levels. Improved knowledge of the character of CKD-associated problems might aid in reforming diagnosis, prevention, and management.
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Rogacka D. Insulin resistance in glomerular podocytes: Potential mechanisms of induction. Arch Biochem Biophys 2021; 710:109005. [PMID: 34371008 DOI: 10.1016/j.abb.2021.109005] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/19/2021] [Accepted: 08/05/2021] [Indexed: 01/15/2023]
Abstract
Glomerular podocytes are a target for the actions of insulin. Accumulating evidence indicates that exposure to nutrient overload induces insulin resistance in these cells, manifested by abolition of the stimulatory effect of insulin on glucose uptake. Numerous recent studies have investigated potential mechanisms of the induction of insulin resistance in podocytes. High glucose concentrations stimulated reactive oxygen species production through NADPH oxidase activation, decreased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, and reduced deacetylase sirtuin 1 (SIRT1) protein levels and activity. Calcium signaling involving transient receptor potential cation channel C, member 6 (TRPC6) also was demonstrated to play an essential role in the regulation of insulin-dependent signaling and glucose uptake in podocytes. Furthermore, podocytes exposed to diabetic environment, with elevated insulin levels become insulin resistant as a result of degradation of insulin receptor (IR), resulting in attenuation of insulin signaling responsiveness. Also elevated levels of palmitic acid appear to be an important factor and contributor to podocytes insulin resistance. This review summarizes cellular and molecular alterations that contribute to the development of insulin resistance in glomerular podocytes.
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Affiliation(s)
- Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
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11
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Rogacka D, Piwkowska A. Beneficial effects of metformin on glomerular podocytes in diabetes. Biochem Pharmacol 2021; 192:114687. [PMID: 34274355 DOI: 10.1016/j.bcp.2021.114687] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 01/15/2023]
Abstract
Podocytes and their foot processes form an important cellular layer of the glomerular barrier involved in regulating glomerular permeability. Disturbances in podocyte function play a central role in the development of proteinuria in diabetic nephropathy. The retraction of podocyte foot processes forming a slit diaphragm is a common feature of proteinuria. Metformin is an oral antidiabetic agent of the biguanide class that is widely recommended for the treatment of high blood glucose in patients with type 2 diabetes mellitus. In addition to lowering glucose, several recent studies have reported potential beneficial effects of metformin on diabetic kidney function. Furthermore, a key molecule of the antidiabetic mechanism of action of metformin is adenosine 5'-monophospate-activated protein kinase (AMPK), as the metformin-induced activation of AMPK is well documented. The present review summarizes current knowledge on the protective effects of metformin against pathological changes in podocytes that are induced by hyperglycemia.
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Affiliation(s)
- Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland.
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12
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Rogacka D, Audzeyenka I, Rachubik P, Szrejder M, Typiak M, Angielski S, Piwkowska A. Involvement of nitric oxide synthase/nitric oxide pathway in the regulation of SIRT1-AMPK crosstalk in podocytes: Impact on glucose uptake. Arch Biochem Biophys 2021; 709:108985. [PMID: 34252390 DOI: 10.1016/j.abb.2021.108985] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/23/2021] [Accepted: 07/08/2021] [Indexed: 01/01/2023]
Abstract
The protein deacetylase sirtuin 1 (SIRT1) and adenosine monophosphate-dependent protein kinase (AMPK) play important roles in the development of insulin resistance. In glomerular podocytes, crosstalk between these two enzymes may be altered under hyperglycemic conditions. SIRT1 protein levels and activity and AMPK phosphorylation decrease under hyperglycemic conditions, with concomitant inhibition of the effect of insulin on glucose uptake into these cells. Nitric oxide (NO)-dependent regulatory signaling pathways have been shown to be downregulated under diabetic conditions. The present study examined the involvement of the NO synthase (NOS)/NO pathway in the regulation of SIRT1-AMPK signaling and glucose uptake in podocytes. We examined the effects of NOS/NO pathway alterations on SIRT1/AMPK signaling and glucose uptake using pharmacological tools and a small-interfering transfection approach. We also examined the ability of the NOS/NO pathway to protect podocytes against high glucose-induced alterations of SIRT1/AMPK signaling and insulin-dependent glucose uptake. Inhibition of the NOS/NO pathway reduced SIRT1 protein levels and activity, leading to a decrease in AMPK phosphorylation and blockade of the effect of insulin on glucose uptake. Treatment with the NO donor S-nitroso-N-acetylpenicillamine (SNAP) prevented high glucose-induced decreases in SIRT1 and AMPK activity and increased GLUT4 protein expression, thereby improving glucose uptake in podocytes. These findings suggest that inhibition of the NOS/NO pathway may result in alterations of the effects of insulin on glucose uptake in podocytes. In turn, the enhancement of NOS/NO pathway activity may prevent these deleterious effects of high glucose concentrations, thus bidirectionally stimulating the SIRT1-AMPK reciprocal activation loop.
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Affiliation(s)
- 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.
| | - 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.
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.
| | - Maria Szrejder
- 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.
| | - 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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13
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Lepa C, Hoppe S, Stöber A, Skryabin BV, Sievers LK, Heitplatz B, Ciarimboli G, Neugebauer U, Lindenmeyer MT, Cohen CD, Drexler HC, Boor P, Weide T, Pavenstädt H, George B. TrkC Is Essential for Nephron Function and Trans-Activates Igf1R Signaling. J Am Soc Nephrol 2021; 32:357-374. [PMID: 33380522 PMCID: PMC8054883 DOI: 10.1681/asn.2020040424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/03/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Injury to kidney podocytes often results in chronic glomerular disease and consecutive nephron malfunction. For most glomerular diseases, targeted therapies are lacking. Thus, it is important to identify novel signaling pathways contributing to glomerular disease. Neurotrophic tyrosine kinase receptor 3 (TrkC) is expressed in podocytes and the protein transmits signals to the podocyte actin cytoskeleton. METHODS Nephron-specific TrkC knockout (TrkC-KO) and nephron-specific TrkC-overexpressing (TrkC-OE) mice were generated to dissect the role of TrkC in nephron development and maintenance. RESULTS Both TrkC-KO and TrkC-OE mice exhibited enlarged glomeruli, mesangial proliferation, basement membrane thickening, albuminuria, podocyte loss, and aspects of FSGS during aging. Igf1 receptor (Igf1R)-associated gene expression was dysregulated in TrkC-KO mouse glomeruli. Phosphoproteins associated with insulin, erb-b2 receptor tyrosine kinase (Erbb), and Toll-like receptor signaling were enriched in lysates of podocytes treated with the TrkC ligand neurotrophin-3 (Nt-3). Activation of TrkC by Nt-3 resulted in phosphorylation of the Igf1R on activating tyrosine residues in podocytes. Igf1R phosphorylation was increased in TrkC-OE mouse kidneys while it was decreased in TrkC-KO kidneys. Furthermore, TrkC expression was elevated in glomerular tissue of patients with diabetic kidney disease compared with control glomerular tissue. CONCLUSIONS Our results show that TrkC is essential for maintaining glomerular integrity. Furthermore, TrkC modulates Igf-related signaling in podocytes.
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Affiliation(s)
- Carolin Lepa
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Sascha Hoppe
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Antje Stöber
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Boris V. Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), Westfälische-Wilhelms-University, Münster, Germany
| | | | - Barbara Heitplatz
- Gerhard-Domagk Institute for Pathology, University Hospital Münster, Münster, Germany
| | | | - Ute Neugebauer
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | - Maja T. Lindenmeyer
- III. Medizinische Klinik und Poliklinik, University Hospital Hamburg-Eppendorf, Germany
| | - Clemens D. Cohen
- Klinik für Nieren-, Hochdruck- und Rheumaerkrankungen, München Klinik Harlaching, Germany
| | - Hannes C.A. Drexler
- Mass Spectrometry Unit, Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Peter Boor
- Institute of Pathology and Department of Nephrology, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany
| | - Thomas Weide
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
| | | | - Britta George
- Medizinische Klinik D, University Hospital Münster, Münster, Germany
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14
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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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15
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Rogacka D, Audzeyenka I, Piwkowska A. Regulation of podocytes function by AMP-activated protein kinase. Arch Biochem Biophys 2020; 692:108541. [PMID: 32781053 DOI: 10.1016/j.abb.2020.108541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/23/2020] [Accepted: 08/06/2020] [Indexed: 01/08/2023]
Abstract
Podocytes are unique, highly specialized, terminally differentiated cells that form an essential, integral part of the glomerular filter. These cells limit the outside border of the glomerular basement membrane, forming a tight barrier that prevents significant protein loss from the capillary space. The slit diaphragm formed by podocytes is crucial for maintaining glomerular integrity and function. They are the target of injury in many glomerular diseases, including hypertension and diabetes mellitus. Accumulating studies have revealed that AMP-activated protein kinase (AMPK), an essential cellular energy sensor, might play a fundamental role in regulating podocyte metabolism and function. AMPK participates in insulin signaling, therefore controls glucose uptake and podocytes insulin sensitivity. It is also involved in insulin-dependent cytoskeleton reorganization in podocytes, mediating glomerular albumin permeability. AMPK plays an important role in the regulation of autophagy/apoptosis processes, which influence podocytes viability. The present review aimed to highlight the molecular mechanisms associated with AMPK that are involved in the regulation of podocyte function in health and disease states.
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Affiliation(s)
- Dorota Rogacka
- Mossakowski Medical Research Centre Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
| | - Irena Audzeyenka
- Mossakowski Medical Research Centre Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
| | - Agnieszka Piwkowska
- Mossakowski Medical Research Centre Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
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16
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Mitrofanova A, Sosa MA, Fornoni A. Lipid mediators of insulin signaling in diabetic kidney disease. Am J Physiol Renal Physiol 2019; 317:F1241-F1252. [PMID: 31545927 PMCID: PMC6879940 DOI: 10.1152/ajprenal.00379.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/19/2019] [Accepted: 09/19/2019] [Indexed: 12/30/2022] Open
Abstract
Diabetic kidney disease (DKD) affects ∼40% of patients with diabetes and is associated with high mortality rates. Among different cellular targets in DKD, podocytes, highly specialized epithelial cells of the glomerular filtration barrier, are injured in the early stages of DKD. Both clinical and experimental data support the role of preserved insulin signaling as a major contributor to podocyte function and survival. However, little is known about the key modulators of podocyte insulin signaling. This review summarizes the novel knowledge that intracellular lipids such as cholesterol and sphingolipids are major determinants of podocyte insulin signaling. In particular, the implications of these lipids on DKD development, progression, and treatment will be addressed.
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Affiliation(s)
- Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, Miller School of Medicine, University of Miami, Miami, Florida
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, Florida
| | - Marie Anne Sosa
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, Miller School of Medicine, University of Miami, Miami, Florida
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17
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Abstract
Finding new therapeutic targets of glomerulosclerosis treatment is an ongoing quest. Due to a living environment of various stresses and pathological stimuli, podocytes are prone to injuries; moreover, as a cell without proliferative potential, loss of podocytes is vital in the pathogenesis of glomerulosclerosis. Thus, sufficient understanding of factors and underlying mechanisms of podocyte injury facilitates the advancement of treating and prevention of glomerulosclerosis. The clinical symptom of podocyte injury is proteinuria, sometimes with loss of kidney functions progressing to glomerulosclerosis. Injury-induced changes in podocyte physiology and function are actually not a simple passive process, but a complex interaction of proteins that comprise the anatomical structure of podocytes at molecular levels. This chapter lists several aspects of podocyte injuries along with potential mechanisms, including glucose and lipid metabolism disorder, hypertension, RAS activation, micro-inflammation, immune disorder, and other factors. These aspects are not technically separated items, but intertwined with each other in the pathogenesis of podocyte injuries.
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18
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Cassis P, Locatelli M, Cerullo D, Corna D, Buelli S, Zanchi C, Villa S, Morigi M, Remuzzi G, Benigni A, Zoja C. SGLT2 inhibitor dapagliflozin limits podocyte damage in proteinuric nondiabetic nephropathy. JCI Insight 2018; 3:98720. [PMID: 30089717 DOI: 10.1172/jci.insight.98720] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/21/2018] [Indexed: 12/21/2022] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors have pleiotropic properties beyond blood glucose-lowering effects and modify important nonglycemic pathways, leading to end-organ protection. SGLT2 inhibitors display renoprotective effects in diabetic kidney disease, which creates a rationale for testing the therapeutic potential of this drug class in nondiabetic chronic kidney disease. Here, we have shown that dapagliflozin provided glomerular protection in mice with protein-overload proteinuria induced by bovine serum albumin (BSA), to a similar extent as an ACE inhibitor used as standard therapy for comparison. Dapagliflozin limited proteinuria, glomerular lesions, and podocyte dysfunction and loss. We provide the observation that SGLT2 was expressed in podocytes and upregulated after BSA injections. Through in vitro studies with cultured podocytes loaded with albumin we have identified what we believe to be a novel mechanism of action for SGLT2 inhibitor that directly targets podocytes and relies on the maintenance of actin cytoskeleton architecture. Whether SGLT2 inhibitors represent a possible future therapeutic option for some patients with proteinuric glomerular disease who do not have as yet an effective treatment will require ad hoc clinical studies.
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Affiliation(s)
- Paola Cassis
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Monica Locatelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Domenico Cerullo
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Simona Buelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Cristina Zanchi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Sebastian Villa
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Marina Morigi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.,Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
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19
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Zhong Y, Motavalli M, Wang KC, Caplan AI, Welter JF, Baskaran H. Dynamics of Intrinsic Glucose Uptake Kinetics in Human Mesenchymal Stem Cells During Chondrogenesis. Ann Biomed Eng 2018; 46:1896-1910. [PMID: 29948374 DOI: 10.1007/s10439-018-2067-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 06/04/2018] [Indexed: 01/25/2023]
Abstract
Chondrogenesis of human mesenchymal stem cells (hMSCs) is an important biological process in many applications including cartilage tissue engineering. We investigated the glucose uptake characteristics of aggregates of hMSCs undergoing chondrogenesis over a 3-week period both experimentally and by using a mathematical model. Initial concentrations of glucose in the medium were varied from 1 to 4.5 g/L to mimic limiting conditions and glucose uptake profiles were obtained. A reaction-diffusion mathematical model was implemented and solved to estimate kinetic parameters. Experimental glucose uptake rates increased with culture time for aggregates treated with higher initial glucose concentrations (3 and 4.5 g/L), whereas they decreased or remained constant for those treated with lower initial glucose concentrations (1 and 2 g/L). Lactate production rate increased by as much as 40% for aggregates treated with higher initial glucose concentrations (2, 3 and 4.5 g/L), whereas it remained constant for those treated with 1 g/L initial glucose concentration. The estimated DNA-normalized maximum glucose uptake rate decreased by a factor of 9 from day 0-2 (12.5 mmol/s/g DNA) to day 6-8 (1.5 mmol/s/g DNA), after which it started to increase. On day 18-20, its value (17.5 mmol/s/g DNA) was about 11 times greater than its lowest value. Further, the extracellular matrix levels of aggregates at day 14 and day 21 correlated with their overall glucose uptake and lactate production. The results suggest that during chondrogenesis, for optimal results, cells require increasing amounts of glucose. Our results also suggest that diffusion limitations play an important role in glucose uptake even in the smaller size aggregate model of chondrogenesis. Further, the results indicate that glucose uptake or lactate production can be a tool for predicting the end quality of tissue during the process of chondrogenesis. The estimated kinetic parameters can be used to model glucose requirements in cartilage tissue engineering applications.
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Affiliation(s)
- Yi Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA.,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Mostafa Motavalli
- Department of Biology, The Skeletal Research Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kuo-Chen Wang
- Department of Biology, The Skeletal Research Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Arnold I Caplan
- Department of Biology, The Skeletal Research Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Jean F Welter
- Department of Biology, The Skeletal Research Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Harihara Baskaran
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, 141C, A.W. Smith Building, 2102 Adelbert Road, Cleveland, OH, 44106-7217, USA. .,Case Center for Multimodal Evaluation of Engineered Cartilage, Case Western Reserve University, Cleveland, OH, 44106, USA.
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20
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Rogacka D, Audzeyenka I, Rychłowski M, Rachubik P, Szrejder M, Angielski S, Piwkowska A. Metformin overcomes high glucose-induced insulin resistance of podocytes by pleiotropic effects on SIRT1 and AMPK. Biochim Biophys Acta Mol Basis Dis 2018; 1864:115-125. [DOI: 10.1016/j.bbadis.2017.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/08/2017] [Accepted: 10/11/2017] [Indexed: 01/09/2023]
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21
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Wasik AA, Lehtonen S. Glucose Transporters in Diabetic Kidney Disease-Friends or Foes? Front Endocrinol (Lausanne) 2018; 9:155. [PMID: 29686650 PMCID: PMC5900043 DOI: 10.3389/fendo.2018.00155] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/22/2018] [Indexed: 12/16/2022] Open
Abstract
Diabetic kidney disease (DKD) is a major microvascular complication of diabetes and a common cause of end-stage renal disease worldwide. DKD manifests as an increased urinary protein excretion (albuminuria). Multiple studies have shown that insulin resistance correlates with the development of albuminuria in non-diabetic and diabetic patients. There is also accumulating evidence that glomerular epithelial cells or podocytes are insulin sensitive and that insulin signaling in podocytes is essential for maintaining normal kidney function. At the cellular level, the mechanisms leading to the development of insulin resistance include mutations in the insulin receptor gene, impairments in the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway, or perturbations in the trafficking of glucose transporters (GLUTs), which mediate the uptake of glucose into cells. Podocytes express several GLUTs, including GLUT1, GLUT2, GLUT3, GLUT4, and GLUT8. Of these, the most studied ones are GLUT1 and GLUT4, both shown to be insulin responsive in podocytes. In the basal state, GLUT4 is preferentially located in perinuclear and cytosolic vesicular structures and to a lesser extent at the plasma membrane. After insulin stimulation, GLUT4 is sorted into GLUT4-containing vesicles (GCVs) that translocate to the plasma membrane. GCV trafficking consists of several steps, including approaching of the GCVs to the plasma membrane, tethering, and docking, after which the lipid bilayers of the GCVs and the plasma membrane fuse, delivering GLUT4 to the cell surface for glucose uptake into the cell. Studies have revealed novel molecular regulators of the GLUT trafficking in podocytes and unraveled unexpected roles for GLUT1 and GLUT4 in the development of DKD, summarized in this review. These findings pave the way for better understanding of the mechanistic pathways associated with the development and progression of DKD and aid in the development of new treatments for this devastating disease.
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22
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Lewko B, Maryn A, Latawiec E, Daca A, Rybczynska A. Angiotensin II Modulates Podocyte Glucose Transport. Front Endocrinol (Lausanne) 2018; 9:418. [PMID: 30087656 PMCID: PMC6066665 DOI: 10.3389/fendo.2018.00418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 07/02/2018] [Indexed: 11/27/2022] Open
Abstract
Podocytes play a central role in the maintenance of the glomerular filtration barrier and are cellular targets of angiotensin II (AngII). Non-hemodynamic pathways of AngII signaling regulate cellular function and mediate podocyte abnormalities that are associated with various glomerulopathies, including diabetic kidney disease. In this study we investigated the capacity of AngII to modulate glucose uptake in mouse podocytes expressing the human AT1 receptor (AT1R+) after 5 days of exposure to normal (NG, 5.6 mmol/L) or to high (HG, 30 mmol/L) glucose. Short (30 min) as well as long-term (24 h) incubations with AngII markedly enhanced glucose transport in both NG and HG cells. In podocytes cultured under NG conditions, AngII inhibited insulin-stimulated glucose uptake. Regardless of the presence or absence of AngII, no effect of insulin on glucose uptake was observed in HG cells. Stimulation of glucose transport by AngII was mediated by protein kinase C and by phosphoinositide 3-kinase. Glucose dependent surface expression of the glucose transporters GLUT1, GLUT2, and GLUT4 was modulated by AngII in a time and glucose concentration dependent manner. Furthermore, despite its inhibitory effect on insulin's action, AngII elevated the number of podocyte insulin receptors in both NG and HG cultured cells. These findings demonstrate that AngII modulates podocyte basal, as well as insulin-dependent glucose uptake by regulating glucose transporters and insulin signaling.
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Affiliation(s)
- Barbara Lewko
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
- *Correspondence: Barbara Lewko
| | - Anna Maryn
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
| | - Elzbieta Latawiec
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
| | - Agnieszka Daca
- Department of Pathology and Experimental Rheumatology, Faculty of Medicine, Medical University of Gdansk, Gdańsk, Poland
| | - Apolonia Rybczynska
- Department of Pathophysiology Faculty of Pharmacy, Medical University of Gdansk, Gdańsk, Poland
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23
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Guo H, Wang B, Li H, Ling L, Niu J, Gu Y. Glucagon-like peptide-1 analog prevents obesity-related glomerulopathy by inhibiting excessive autophagy in podocytes. Am J Physiol Renal Physiol 2017; 314:F181-F189. [PMID: 29070572 DOI: 10.1152/ajprenal.00302.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To investigate the role of glucagon-like peptide-1 analog (GLP-1) in high-fat diet-induced obesity-related glomerulopathy (ORG). Male C57BL/6 mice fed a high-fat diet for 12 wk were treated with GLP-1 (200 μg/kg) or 0.9% saline for 4 wk. Fasting blood glucose and insulin and the expression of podocin, nephrin, phosphoinositide 3-kinase (PI3K), glucose transporter type (Glut4), and microtubule-associated protein 1A/1B-light chain 3 (LC3) were assayed. Glomerular morphology and podocyte foot structure were evaluated by periodic acid-Schiff staining and electron microscopy. Podocytes were treated with 150 nM GLP-1 and incubated with 400 μM palmitic acid (PA) for 12 h. The effect on autophagy was assessed by podocyte-specific Glut4 siRNA. Insulin resistance and autophagy were assayed by immunofluorescence and Western blotting. The high-fat diet resulted in weight gain, ectopic glomerular lipid accumulation, increased insulin resistance, and fusion of podophyte foot processes. The decreased translocation of Glut4 to the plasma membrane and excess autophagy seen in mice fed a high-fat diet and in PA-treated cultured podocytes were attenuated by GLP-1. Podocyte-specific Glut4 siRNA promoted autophagy, and rapamycin-enhanced autophagy worsened the podocyte injury caused by PA. Excess autophagy in podocytes was induced by inhibition of Glut4 translocation to the plasma membrane and was involved in the pathology of ORG. GLP-1 restored insulin sensitivity and ameliorated renal injury by decreasing the level of autophagy.
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Affiliation(s)
- Honglei Guo
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University , Shanghai , China.,Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital), Nanjing, Jiangsu Province, China
| | - Bin Wang
- Department of Nephrology, Zhongda Hospital Southeast University, Nanjing, Jiangsu Province, China
| | - Hongmei Li
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University , Shanghai , China
| | - Lilu Ling
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University , Shanghai , China
| | - Jianying Niu
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University , Shanghai , China
| | - Yong Gu
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University , Shanghai , China.,Division of Nephrology, Huashan Hospital and Institute of Nephrology, Fudan University , Shanghai , China
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Rogacka D, Piwkowska A, Audzeyenka I, Angielski S, Jankowski M. SIRT1-AMPK crosstalk is involved in high glucose-dependent impairment of insulin responsiveness in primary rat podocytes. Exp Cell Res 2016; 349:328-338. [DOI: 10.1016/j.yexcr.2016.11.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/14/2016] [Accepted: 11/05/2016] [Indexed: 11/29/2022]
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25
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Insulin signaling: implications for podocyte biology in diabetic kidney disease. Curr Opin Nephrol Hypertens 2015; 24:104-10. [PMID: 25415617 DOI: 10.1097/mnh.0000000000000078] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Several key elements of the insulin signaling cascade contribute to podocyte function and survival. While it was initially thought that the consequences of altered insulin signaling to podocyte function was strictly related to altered glucose uptake, it has become clear that upstream signaling events involved in cell survival, lipid metabolism or nutrient sensing and modulated by insulin are strong independent contributors to podocyte function. RECENT FINDINGS Akt2, the major isoform of Akt activated following cellular insulin stimulation, protects against the progression of renal disease in nephron-deficient mice, and podocyte-specific deletion of Akt2 results in a more rapid progression of experimental glomerular disease. In diabetes, podocyte mammalian target of rapamycin activation clearly contributes to podocyte injury and regulated autophagy. Furthermore, podocyte-specific glucose transporter type 4 (GLUT4) deficiency protects podocytes by preventing mammalian target of rapamycin signaling independently of glucose uptake. Finally, intracellular lipids have been recently recognized as major modulators of podocyte insulin signaling and as a new therapeutic target. SUMMARY The identification of new contributors to podocyte insulin signaling is of extreme translational value as it may lead to new drug development strategies for diabetic kidney disease, as well as for other proteinuric kidney diseases.
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Wang W, Ding XQ, Gu TT, Song L, Li JM, Xue QC, Kong LD. Pterostilbene and allopurinol reduce fructose-induced podocyte oxidative stress and inflammation via microRNA-377. Free Radic Biol Med 2015; 83:214-26. [PMID: 25746774 DOI: 10.1016/j.freeradbiomed.2015.02.029] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/08/2015] [Accepted: 02/23/2015] [Indexed: 02/07/2023]
Abstract
High dietary fructose is an important causative factor in the development of metabolic syndrome-associated glomerular podocyte oxidative stress and injury. Here, we identified microRNA-377 (miR-377) as a biomarker of oxidative stress in renal cortex of fructose-fed rats, which correlated with podocyte injury and albuminuria in metabolic syndrome. Fructose feeding increased miR-377 expression, decreased superoxide dismutase (SOD) expression and activity, and caused O2(-) and H2O2 overproduction in kidney cortex or glomeruli of rats. This reactive oxygen species induction increased p38 MAPK phosphorylation and thioredoxin-interacting protein (TXNIP) expression and activated the NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome to produce interleukin-1β in kidney glomeruli of fructose-fed rats. These pathological processes were further evaluated in cultured differentiated podocytes exposed to 5mM fructose, or transfected with miR-377 mimic/inhibitor and TXNIP siRNA, or co-incubated with p38 MAPK inhibitor, demonstrating that miR-377 overexpression activates the O2(-)/p38 MAPK/TXNIP/NLRP3 inflammasome pathway to promote oxidative stress and inflammation in fructose-induced podocyte injury. Antioxidants pterostilbene and allopurinol were found to ameliorate fructose-induced hyperuricemia, podocyte injury, and albuminuria in rats. More importantly, pterostilbene and allopurinol inhibited podocyte miR-377 overexpression to increase SOD1 and SOD2 levels and suppress the O2(-)/p38 MAPK/TXNIP/NLRP3 inflammasome pathway activation in vivo and in vitro, consistent with the reduction of oxidative stress and inflammation. These findings suggest that miR-377 plays an important role in glomerular podocyte oxidative stress, inflammation, and injury driven by high fructose. Inhibition of miR-377 by antioxidants may be a promising therapeutic strategy for the prevention of metabolic syndrome-associated glomerular podocyte injury.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Xiao-Qin Ding
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Ting-Ting Gu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Lin Song
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Jian-Mei Li
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Qiao-Chu Xue
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China
| | - Ling-Dong Kong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, People׳s Republic of China.
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Involvement of the AMPK–PTEN pathway in insulin resistance induced by high glucose in cultured rat podocytes. Int J Biochem Cell Biol 2014; 51:120-30. [DOI: 10.1016/j.biocel.2014.04.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/28/2014] [Accepted: 04/09/2014] [Indexed: 11/17/2022]
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28
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Insulin stimulates glucose transport via protein kinase G type I alpha-dependent pathway in podocytes. Biochem Biophys Res Commun 2014; 446:328-34. [PMID: 24602613 DOI: 10.1016/j.bbrc.2014.02.108] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 02/24/2014] [Indexed: 01/09/2023]
Abstract
Podocyte resistance to the actions of insulin on glucose transport could contribute to the pathogenesis of diabetic podocytopathy (DP) via disturbances in cyclic-dependent protein kinase signaling. To determine whether cGMP-dependent protein kinase (PKG) is involved in the insulin regulation of glucose transport, we measured insulin-dependent glucose uptake into cultured rat podocytes under conditions of modified PKG activity using pharmacological (PKG activator or inhibitor) and biochemical (siRNA PKGIα, siRNA insulin receptor β) means. Our findings indicate the participation of PKG in insulin-stimulated transport and provide new insights into how PKG may trigger the resistance of glucose transport to insulin in DP.
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Guzman J, Jauregui AN, Merscher-Gomez S, Maiguel D, Muresan C, Mitrofanova A, Diez-Sampedro A, Szust J, Yoo TH, Villarreal R, Pedigo C, Molano RD, Johnson K, Kahn B, Hartleben B, Huber TB, Saha J, Burke GW, Abel ED, Brosius FC, Fornoni A. Podocyte-specific GLUT4-deficient mice have fewer and larger podocytes and are protected from diabetic nephropathy. Diabetes 2014; 63:701-14. [PMID: 24101677 PMCID: PMC3900538 DOI: 10.2337/db13-0752] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Podocytes are a major component of the glomerular filtration barrier, and their ability to sense insulin is essential to prevent proteinuria. Here we identify the insulin downstream effector GLUT4 as a key modulator of podocyte function in diabetic nephropathy (DN). Mice with a podocyte-specific deletion of GLUT4 (G4 KO) did not develop albuminuria despite having larger and fewer podocytes than wild-type (WT) mice. Glomeruli from G4 KO mice were protected from diabetes-induced hypertrophy, mesangial expansion, and albuminuria and failed to activate the mammalian target of rapamycin (mTOR) pathway. In order to investigate whether the protection observed in G4 KO mice was due to the failure to activate mTOR, we used three independent in vivo experiments. G4 KO mice did not develop lipopolysaccharide-induced albuminuria, which requires mTOR activation. On the contrary, G4 KO mice as well as WT mice treated with the mTOR inhibitor rapamycin developed worse adriamycin-induced nephropathy than WT mice, consistent with the fact that adriamycin toxicity is augmented by mTOR inhibition. In summary, GLUT4 deficiency in podocytes affects podocyte nutrient sensing, results in fewer and larger cells, and protects mice from the development of DN. This is the first evidence that podocyte hypertrophy concomitant with podocytopenia may be associated with protection from proteinuria.
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Affiliation(s)
- Johanna Guzman
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - Alexandra N. Jauregui
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Sandra Merscher-Gomez
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - Dony Maiguel
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Cristina Muresan
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - Alla Mitrofanova
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - Ana Diez-Sampedro
- Department of Physiology, Miller School of Medicine, University of Miami, Miami, FL
| | - Joel Szust
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Tae-Hyun Yoo
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL
| | - Rodrigo Villarreal
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - Christopher Pedigo
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
| | - R. Damaris Molano
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Kevin Johnson
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
| | - Barbara Kahn
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | | | - Tobias B. Huber
- Division of Nephrology, Freiburg University, Freiburg, Germany
| | - Jharna Saha
- Division of Nephrology, University of Michigan, Ann Arbor, MI
| | - George W. Burke
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL
| | - E. Dale Abel
- Division of Endocrinology, Metabolism and Diabetes and Program in Molecular Medicine, University of Utah, Salt Lake City, UT
| | | | - Alessia Fornoni
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL
- Department of Medicine, Division of Nephrology and Hypertension, Miller School of Medicine, University of Miami, Miami, FL
- Corresponding author: Alessia Fornoni,
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Piwkowska A, Rogacka D, Audzeyenka I, Angielski S, Jankowski M. High glucose increases glomerular filtration barrier permeability by activating protein kinase G type Iα subunits in a Nox4-dependent manner. Exp Cell Res 2013; 320:144-52. [PMID: 24041960 DOI: 10.1016/j.yexcr.2013.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 11/29/2022]
Abstract
Hyperglycemia is a primary factor that disturbs podocyte function in the glomerular filtration process; this disturbance leads to the development of diabetic nephropathy, and ultimately, renal failure. Podocyte function may also be altered by biological agents that modify protein kinase activity, including the cGMP-activated protein kinase type Iα (PKGIα). We hypothesized that hyperglycemia-induced podocyte protein hyperpermeability was dependent on PKGIα activation, and that PKGIα was activated via dimerization induced by reactive oxygen species. This hypothesis was investigated in rat podocytes cultured in high glucose (HG, 30 mM). Protein expression was measured with Western blot and immunofluorescence. Podocyte permeability was measured with a transmembrane albumin flux assay. We found that HG increased podocyte permeability in long-term incubations (1, 3, and 5 days); permeability was increased by 66% on day 5. This effect was abolished with apocynin, a NAD(P)H inhibitor, and Rp-8-Br-cGMPS, a PKG inhibitor. It was also abolished by introducing small interfering RNAs (siRNAs) against Nox4 and PKGIα into cultured podocytes. Furthermore, HG increased PKGIα dimerization by 138% (0.23 ± 0.04 vs. 0.54 ± 0.09; P<0.05); this effect was abolished with a siRNA against Nox4. Our observations suggested that HG could increase albumin permeability across the podocyte filtration barrier via Nox4-dependent PKGIα dimerization.
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Affiliation(s)
- Agnieszka Piwkowska
- Mossakowski Medical Research Centre Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology Dębinki 7, Gdańsk 80-211, Poland.
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31
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Piwkowska A, Rogacka D, Kasztan M, Angielski S, Jankowski M. Insulin increases glomerular filtration barrier permeability through dimerization of protein kinase G type Iα subunits. Biochim Biophys Acta Mol Basis Dis 2013; 1832:791-804. [DOI: 10.1016/j.bbadis.2013.02.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 02/04/2013] [Accepted: 02/06/2013] [Indexed: 12/11/2022]
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32
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Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes. Biochem Biophys Res Commun 2012; 428:167-72. [DOI: 10.1016/j.bbrc.2012.10.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 10/05/2012] [Indexed: 01/11/2023]
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33
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Sun L, Guo Y, Fu C, Li J, Li Z. Simultaneous separation and purification of total polyphenols, chlorogenic acid and phlorizin from thinned young apples. Food Chem 2012; 136:1022-9. [PMID: 23122158 DOI: 10.1016/j.foodchem.2012.09.036] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/11/2012] [Accepted: 09/06/2012] [Indexed: 01/07/2023]
Abstract
An efficient preparative separation of polyphenols from thinned young apples (TYA) has been developed in the present study. X-5 resin was verified to offer the best adsorption capacity and desorption ratio for total polyphenols among the eight macroporous resins investigated. Influential factors, such as pH value and concentration of feeding solution, strippant, and adsorption isotherm to the separation of total polyphenols, were successively investigated on X-5 resin. After one run treatment, the phenolic content was increased 2.12-fold from 35.17% to 74.64%, with a recovery yield of 89.35%. Chlorogenic acid and phlorizin were selectively purified using X-5 and polyamide resins. The contents of chlorogenic acid and phlorizin were 15.20% and 97.52% with recovery yields of 89.16% and 64.95%, respectively. The method developed will provide a potential approach for its wide industrial and pharmaceutical use.
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Affiliation(s)
- Lijun Sun
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, PR China
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34
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Piwkowska A, Rogacka D, Jankowski M, Kocbuch K, Angielski S. Hydrogen peroxide induces dimerization of protein kinase G type Iα subunits and increases albumin permeability in cultured rat podocytes. J Cell Physiol 2012; 227:1004-16. [PMID: 21520075 DOI: 10.1002/jcp.22810] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Podocytes help regulate filtration barrier permeability in the kidneys. They express contractile proteins that are characteristic of smooth muscle cells as well as receptors for vasoactive factors such as angiotensin II and atrial natriuretic peptide (ANP). The later one generates intracellular cGMP, with subsequent activation of cGMP-dependent protein kinase; PKG (isoform PKGIα and PKGIβ). In this study, we asked whether hydrogen peroxide (H(2)O(2)), a physiological vasorelaxing factor, affected podocyte permeability and the podoctye PKGIα signaling pathway. Expression of PKGIα was confirmed in cultured rat podocytes using RT-PCR, immunofluorescence, and Western blotting. Exposure of podocytes to exogenous H(2)O(2) (100 µM) in non-reducing conditions increased the formation of PKGIα interprotein disulfide bonds, affected the phosphorylation of PKG target proteins, namely MYPT1 (maximal increase of about 57% at 30 min) and MLC (maximal decrease of about 62% at 10 min). Furthermore, H(2)O(2) increased the permeability of a layer of podocytes to albumin: Transmembrane flux for albumin increased five-fold (106.6 ± 5.2 µg/ml vs. 20.2 ± 2.5 µg/ml, P < 0.05, n = 5), and the PKG inhibitor Rp-8-Br-cGMPS (100 µM) prevented the flux increase. These data suggest that oxidative modulation of PKGIα in podocytes plays an important
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Affiliation(s)
- Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre Polish Academy of Sciences, Gdańsk, Poland.
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35
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Stieger N, Worthmann K, Schiffer M. The role of metabolic and haemodynamic factors in podocyte injury in diabetes. Diabetes Metab Res Rev 2011; 27:207-15. [PMID: 21309047 DOI: 10.1002/dmrr.1164] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Podocyte loss is a common feature in human diabetes as well as in experimental diabetes in rodents. Almost all components of the diabetic milieu lead to serious podocyte stress, driving the cells towards cell cycle arrest and hypertrophy, detachment and apoptosis. Common pathway components induced by high glucose and advanced glycation end-products are reactive oxygen species, cyclin-dependent kinases (p27(Kip1)) and transforming growth factor-beta. In addition, mechanical stresses by stretch or shear forces, insulin deficiency or insulin resistance are independent components resulting in podocyte apoptosis and detachment. In this review, we discuss the common pathways leading to podocyte death as well as novel pathways and concepts of podocyte dedifferentiation and detachment that influence the progression of diabetic glomerulopathy.
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Affiliation(s)
- Nicole Stieger
- Division of Nephrology, Department of Medicine, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover, Germany
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36
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Karczewska J, Piwkowska A, Rogacka D, Stępiński J, Angielski S, Jankowski M. Purinergic modulation of glucose uptake into cultured rat podocytes: effect of diabetic milieu. Biochem Biophys Res Commun 2010; 404:723-7. [PMID: 21163251 DOI: 10.1016/j.bbrc.2010.12.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 12/09/2010] [Indexed: 11/29/2022]
Abstract
Extracellular purines act via P1 and P2 receptors on podocytes and may influence on their function. This action may be modified under various (patho)physiological conditions leading to development of podocytopathy. Aim of study was to investigate effects of diabetic milieu, represented by high glucose concentration (HG, 30 mM glucose) on purinergic-induced changes of 2-deoxy-D-glucose (2-DG) uptake and on extracellular purines metabolism in cultured rat podocytes. Basal 2-DG uptake was 2.7-fold enhanced in HG compared to normal glucose concentration, NG (1271 ± 86 vs. 477 ± 37 nmol/h/mg protein, P<0.001). ATP stimulated 2-DG uptake by 44 ± 4% and 29 ± 5% in NG and HG, respectively. ATP analogues, β, γ-methylene ATP and 2-methylthio ATP stimulated 2-DG uptake in range of 18-34% in NG and 16-17% in HG. Benzoylbenzoyl ATP increased 2-DG uptake about 24 ± 2% in NG however, its effect in HG reached 50 ± 1%. The antagonists of P2 receptors (suramin, reactive blue 2, PPADS) decreased basal 2-DG uptake in NG and HG; suramin and reactive blue 2 at average of 15 ± 4% in NG but in HG the effect was in following order: suramin 28 ± 3%; PPADS 20 ± 3% and RB-2 9 ± 0.9%. Extracellular adenosine concentration was higher in HG than in NG (0.48 ± 0.01 vs. 5.05 ± 0.39 μM, P < 0.05), however intracellular ATP content and extracellular ATP concentration were not affected. Neither ecto-ATPase nor ecto-5'-nucleotidase activities were affected in HG. In conclusion, diabetic milieu affects purinergic modulation of glucose transport into podocytes which may play a role in development of diabetic podocytopathy.
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Affiliation(s)
- Joanna Karczewska
- Laboratory of Molecular and Cellular Nephrology, M. Mossakowski Medical Research Centre, Polish Academy of Science, Medical University of Gdańsk, Poland
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37
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Rogacka D, Piwkowska A, Jankowski M, Kocbuch K, Dominiczak MH, Stępiński JK, Angielski S. Expression of GFAT1 and OGT in podocytes: Transport of glucosamine and the implications for glucose uptake into these cells. J Cell Physiol 2010; 225:577-84. [DOI: 10.1002/jcp.22242] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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38
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Zhang H, Schin M, Saha J, Burke K, Holzman LB, Filipiak W, Saunders T, Xiang M, Heilig CW, Brosius FC. Podocyte-specific overexpression of GLUT1 surprisingly reduces mesangial matrix expansion in diabetic nephropathy in mice. Am J Physiol Renal Physiol 2010; 299:F91-8. [PMID: 20375116 DOI: 10.1152/ajprenal.00021.2010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Increased expression of the facilitative glucose transporter, GLUT1, leads to glomerulopathy that resembles diabetic nephropathy, whereas prevention of enhanced GLUT1 expression retards nephropathy. While many of the GLUT1-mediated effects are likely due to mesangial cell effects, we hypothesized that increased GLUT1 expression in podocytes also contributes to the progression of diabetic nephropathy. Therefore, we generated two podocyte-specific GLUT1 transgenic mouse lines (driven by a podocin promoter) on a db/m C57BLKS background. Progeny of the two founders were used to generate diabetic db/db and control db/m littermate mice. Immunoblots of glomerular lysates showed that transgenic mice had a 3.5-fold (line 1) and 2.1-fold (line 2) increase in GLUT1 content compared with wild-type mice. Both lines showed similar increases in fasting blood glucose and body weights at 24 wk of age compared with wild-type mice. Mesangial index (percent PAS-positive material in the mesangial tuft) increased 88% (line 1) and 75% (line 2) in the wild-type diabetic mice but only 48% (line 1) and 39% (line 2) in the diabetic transgenic mice (P < 0.05, transgenic vs. wild-type mice). This reduction in mesangial expansion was accompanied by a reduction in fibronectin accumulation, and vascular endothelial growth factor (VEGF) levels increased only half as much in the transgenic diabetic mice as in wild-type diabetic mice. Levels of nephrin, neph1, CD2AP, podocin, and GLUT4 were not significantly different in transgenic compared with wild-type mice. Taken together, increased podocyte GLUT1 expression in diabetic mice does not contribute to early diabetic nephropathy; surprisingly, it protects against mesangial expansion and fibronectin accumulation possibly by blunting podocyte VEGF increases.
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Affiliation(s)
- Hongyu Zhang
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-0680, USA
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39
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Lewko B, Stepinski J. Hyperglycemia and mechanical stress: Targeting the renal podocyte. J Cell Physiol 2009; 221:288-95. [DOI: 10.1002/jcp.21856] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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40
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Phlorizin prevents glomerular hyperfiltration but not hypertrophy in diabetic rats. EXPERIMENTAL DIABETES RESEARCH 2008; 2008:305403. [PMID: 18769499 PMCID: PMC2522335 DOI: 10.1155/2008/305403] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 07/09/2008] [Indexed: 12/22/2022]
Abstract
The relationships of renal and glomerular hypertrophies to development of hyperfiltration and proteinuria early in streptozotocin-induced diabetes were explored. Control, diabetic, phlorizin-treated controls, and diabetic male Fischer rats were used. Phlorizin (an Na+-glucose cotransport inhibitor) was given at a dose sufficient to normalize blood glucose. Inulin clearance (Cinulin) and protein excretion rate (PER) were measured. For morphometry, kidney sections were stained with periodic acid Schiff. At one week, diabetes PER increased 2.8-folds (P < .001), Cinulin increased 80% (P < .01). Kidney wet and dry weights increased 10%–12% (P < .05), and glomerular tuft area increased 9.3% (P < .001). Phlorizin prevented proteinuria, hyperfiltration, and kidney hypertrophy, but not glomerular hypertrophy. Thus, hyperfiltration, proteinuria, and whole kidney hypertrophy were related to hyperglycemia but not to glomerular growth. Diabetic glomerular hypertrophy constitutes an early event in the progression of glomerular pathology which occurs in the absence of mesangial expansion and persists even after changes in protein excretion and GFR are reversed through glycemic control.
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41
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Saleem MA, Zavadil J, Bailly M, McGee K, Witherden IR, Pavenstadt H, Hsu H, Sanday J, Satchell SC, Lennon R, Ni L, Bottinger EP, Mundel P, Mathieson PW. The molecular and functional phenotype of glomerular podocytes reveals key features of contractile smooth muscle cells. Am J Physiol Renal Physiol 2008; 295:F959-70. [PMID: 18684887 PMCID: PMC2576149 DOI: 10.1152/ajprenal.00559.2007] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The glomerular podocyte is a highly specialized cell, with the ability to ultrafilter blood and support glomerular capillary pressures. However, little is known about either the genetic programs leading to this functionality or the final phenotype. We approached this question utilizing a human conditionally immortalized cell line, which differentiates from a proliferating epithelial phenotype to a differentiated form. We profiled gene expression during several time points during differentiation and grouped the regulated genes into major functional categories. A novel category of genes that was upregulated during differentiation was of smooth muscle-related molecules. We further examined the smooth muscle phenotype and showed that podocytes consistently express the differentiated smooth muscle markers smoothelin and calponin and the specific transcription factor myocardin, both in vitro and in vivo. The contractile contribution of the podocyte to the glomerular capillary is controversial. We demonstrated using two novel techniques that podocytes contract vigorously in vitro when differentiated and in real time were able to demonstrate that angiotensin II treatment decreases monolayer resistance, morphologically correlating with enhanced contractility. We conclude that the mature podocyte in vitro possesses functional apparatus of contractile smooth muscle cells, with potential implications for its in vivo ability to regulate glomerular dynamic and permeability characteristics.
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Affiliation(s)
- Moin A Saleem
- Academic and Children's Renal Unit, University of Bristol, Lifeline Bldg., Southmead Hospital, Bristol, BS10 5NB, United Kingdom.
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Coward RJM, Welsh GI, Yang J, Tasman C, Lennon R, Koziell A, Satchell S, Holman GD, Kerjaschki D, Tavaré JM, Mathieson PW, Saleem MA. The human glomerular podocyte is a novel target for insulin action. Diabetes 2005; 54:3095-102. [PMID: 16249431 DOI: 10.2337/diabetes.54.11.3095] [Citation(s) in RCA: 225] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Microalbuminuria is significant both as the earliest stage of diabetic nephropathy and as an independent cardiovascular risk factor in nondiabetic subjects, in whom it is associated with insulin resistance. The link between disorders of cellular insulin metabolism and albuminuria has been elusive. Here, we report using novel conditionally immortalized human podocytes in vitro and human glomeruli ex vivo that the podocyte, the principal cell responsible for prevention of urinary protein loss, is insulin responsive and able to approximately double its glucose uptake within 15 min of insulin stimulation. Conditionally immortalized human glomerular endothelial cells do not respond to insulin, suggesting that insulin has a specific effect on the podocyte in the glomerular filtration barrier. The insulin response of the podocyte occurs via the facilitative glucose transporters GLUT1 and GLUT4, and this process is dependent on the filamentous actin cytoskeleton. Insulin responsiveness in this key structural component of the glomerular filtration barrier may have central relevance for understanding of diabetic nephropathy and for the association of albuminuria with states of insulin resistance.
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Affiliation(s)
- Richard J M Coward
- Academic and Children's Renal Unit, University of Bristol, Southmead Hospital, Bristol, UK BS10 5NB
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