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Piwkowska A, Rachubik P, Typiak M, Kulesza T, Audzeyenka I, Saleem MA, Gruba N, Wysocka M, Lesner A, Rogacka D. ADAM10 as a major activator of reactive oxygen species production and klotho shedding in podocytes under diabetic conditions. Biochem Pharmacol 2024; 225:116328. [PMID: 38815628 DOI: 10.1016/j.bcp.2024.116328] [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: 11/13/2023] [Revised: 05/14/2024] [Accepted: 05/28/2024] [Indexed: 06/01/2024]
Abstract
Early stages of diabetes are characterized by elevations of insulin and glucose concentrations. Both factors stimulate reactive oxygen species (ROS) production, leading to impairments in podocyte function and disruption of the glomerular filtration barrier. Podocytes were recently shown to be an important source of αKlotho (αKL) expression. Low blood Klotho concentrations are also associated with an increase in albuminuria, especially in patients with diabetes. We investigated whether ADAM10, which is known to cleave αKL, is activated in glomeruli and podocytes under diabetic conditions and the potential mechanisms by which ADAM10 mediates ROS production and disturbances of the glomerular filtration barrier. In cultured human podocytes, high glucose increased ADAM10 expression, shedding, and activity, NADPH oxidase activity, ROS production, and albumin permeability. These effects of glucose were inhibited when cells were pretreated with an ADAM10 inhibitor or transfected with short-hairpin ADAM10 (shADAM10) or after the addition soluble Klotho. We also observed increases in ADAM10 activity, NOX4 expression, NADPH oxidase activity, and ROS production in αKL-depleted podocytes. This was accompanied by an increase in albumin permeability in shKL-expressing podocytes. The protein expression and activity of ADAM10 also increased in isolated glomeruli and urine samples from diabetic rats. Altogether, these results reveal a new mechanism by which hyperglycemia in diabetes increases albumin permeability through ADAM10 activation and an increase in oxidative stress via NOX4 enzyme activation. Moreover, αKlotho downregulates ADAM10 activity and supports redox balance, consequently protecting the slit diaphragm of podocyteσ under hyperglycemic conditions.
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Affiliation(s)
- 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.
| | - Patrycja Rachubik
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Marlena Typiak
- University of Gdansk, Faculty of Biology, Gdansk, Poland
| | - Tomasz Kulesza
- 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
| | - Moin A Saleem
- Bristol Renal, University of Bristol, Bristol, United Kingdom
| | - Natalia Gruba
- University of Gdansk, Faculty of Chemistry, Gdańsk, Poland
| | | | - Adam Lesner
- University of Gdansk, Faculty of Chemistry, 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
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Gong L, Wang R, Wang X, Liu J, Han Z, Li Q, Jin Y, Liao H. Research progress of natural active compounds on improving podocyte function to reduce proteinuria in diabetic kidney disease. Ren Fail 2023; 45:2290930. [PMID: 38073545 PMCID: PMC11001328 DOI: 10.1080/0886022x.2023.2290930] [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: 08/29/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Diabetic kidney disease (DKD) is a primary cause of end-stage renal disease. Proteinuria is a clinical indicator of the different stages of DKD, and podocyte injury is a major cause of proteinuria. Podocyte-specific proteins (PSPs) play important roles in the normal filtration of podocytes. Studies have shown that natural active compounds (NACs) can ameliorate proteinuria; however, the mechanism related to PSPs needs to be explored. In this study, the five stages of DKD related to proteinuria and the functions of PSPs are displayed separately. Mechanisms for ameliorating proteinuria and improving the PSPs of the 15 NACs are summarized. The in vitro and in vivo mechanistic research showed that five compounds, astragaloside IV, ligustrazine, berberine, emodin and resveratrol, exerted renal protective effects via AMPK signaling, icariin and berberine via TLR4 signaling, hirudin and baicalin via MAPK signaling, curcumin and baicalin via NF-κB signaling, and emodin via protein kinase RNA-like endoplasmic reticulum kinase signaling. The 13 PSPs were divided into five categories: actin cytoskeleton, basal domain, apical domain, slit diaphragm, and others. In conclusion, anti-inflammatory effects, anti-oxidative stress, and enhanced autophagy are the main mechanisms underlying the ameliorative effects of NACs. Podocyte apoptosis is mainly related to nephrin and podocin, which are the most studied slit diaphragm PSPs.
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Affiliation(s)
- Le Gong
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Rui Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Xinyu Wang
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Jing Liu
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Zhaodi Han
- Drug Clinical Trial Institution, Fifth Hospital of Shanxi Medical University (Shanxi Provincial People’s Hospital), Taiyuan, China
| | - Qian Li
- Drug Clinical Trial Institution, Fifth Hospital of Shanxi Medical University (Shanxi Provincial People’s Hospital), Taiyuan, China
| | - Yi Jin
- Drug Clinical Trial Institution, Fifth Hospital of Shanxi Medical University (Shanxi Provincial People’s Hospital), Taiyuan, China
| | - Hui Liao
- Drug Clinical Trial Institution, Fifth Hospital of Shanxi Medical University (Shanxi Provincial People’s Hospital), Taiyuan, China
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Rachubik P, Rogacka D, Audzeyenka I, Typiak M, Wysocka M, Szrejder M, Lesner A, Piwkowska A. Role of lysosomes in insulin signaling and glucose uptake in cultured rat podocytes. Biochem Biophys Res Commun 2023; 679:145-159. [PMID: 37696068 DOI: 10.1016/j.bbrc.2023.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/30/2023] [Accepted: 09/05/2023] [Indexed: 09/13/2023]
Abstract
Podocytes are sensitive to insulin, which governs the functional and structural integrity of podocytes that are essential for proper function of the glomerular filtration barrier. Lysosomes are acidic organelles that are implicated in regulation of the insulin signaling pathway. Cathepsin D (CTPD) and lysosome-associated membrane protein 1 (LAMP1) are major lysosomal proteins that reflect the functional state of lysosomes. However, the effect of insulin on lysosome activity and role of lysosomes in the regulation of insulin-dependent glucose uptake in podocytes are unknown. Our studies showed that the short-term incubation of podocytes with insulin decreased LAMP1 and CTPD mRNA levels. Insulin and bafilomycin A1 reduced both the amounts of LAMP1 and CTPD proteins and activity of CTPD, which were associated with a decrease in the fluorescence intensity of lysosomes that were labeled with LysoTracker. Bafilomycin A1 inhibited insulin-dependent endocytosis of the insulin receptor and increased the amounts of the insulin receptor and glucose transporter 4 on the cell surface of podocytes. Bafilomycin A1 also inhibited insulin-dependent glucose uptake despite an increase in the amount of glucose transporter 4 in the plasma membrane of podocytes. These results suggest that lysosomes are signaling hubs that may be involved in the coupling of insulin signaling with the regulation of glucose uptake in podocytes. The dysregulation of this mechanism can lead to the dysfunction of podocytes and development of insulin resistance.
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Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Marlena Typiak
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59 St, Gdansk, 80-308, Poland.
| | - Magdalena Wysocka
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Adam Lesner
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St, Gdansk, 80-308, Poland; Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St, Gdansk, 80-308, Poland.
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Rachubik P, Rogacka D, Audzeyenka I, Szrejder M, Topolewska A, Rychłowski M, Piwkowska A. The Role of PKGIα and AMPK Signaling Interplay in the Regulation of Albumin Permeability in Cultured Rat Podocytes. Int J Mol Sci 2023; 24:ijms24043952. [PMID: 36835364 PMCID: PMC9964913 DOI: 10.3390/ijms24043952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
The permeability of the glomerular filtration barrier (GFB) is mainly regulated by podocytes and their foot processes. Protein kinase G type Iα (PKGIα) and adenosine monophosphate-dependent kinase (AMPK) affect the contractile apparatus of podocytes and influence the permeability of the GFB. Therefore, we studied the interplay between PKGIα and AMPK in cultured rat podocytes. The glomerular permeability to albumin and transmembrane FITC-albumin flux decreased in the presence of AMPK activators and increased in the presence of PKG activators. The knockdown of PKGIα or AMPK with small-interfering RNA (siRNA) revealed a mutual interaction between PKGIα and AMPK and influenced podocyte permeability to albumin. Moreover, PKGIα siRNA activated the AMPK-dependent signaling pathway. AMPKα2 siRNA increased basal levels of phosphorylated myosin phosphate target subunit 1 and decreased the phosphorylation of myosin light chain 2. Podocytes that were treated with AMPK or PKG activators were characterized by the different organization of actin filaments within the cell. Our findings suggest that mutual interactions between PKGIα and AMPKα2 regulate the contractile apparatus and permeability of the podocyte monolayer to albumin. Understanding this newly identified molecular mechanism in podocytes provides further insights into the pathogenesis of glomerular disease and novel therapeutic targets for glomerulopathies.
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Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Correspondence: ; Tel.: +48-585235486
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Anna Topolewska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Michał Rychłowski
- Intercollegiate Faculty of Biotechnology, University of Gdansk, Medical University of Gdansk, Abrahama 58 St., 80-307 Gdansk, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
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Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
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6
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Rachubik P, Szrejder M, Rogacka D, Typiak M, Audzeyenka I, Kasztan M, Pollock DM, Angielski S, Piwkowska A. Insulin controls cytoskeleton reorganization and filtration barrier permeability via the PKGIα-Rac1-RhoA crosstalk in cultured rat podocytes. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119301. [PMID: 35642843 DOI: 10.1016/j.bbamcr.2022.119301] [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: 01/11/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Podocyte foot processes are an important cellular layer of the glomerular barrier that regulates glomerular permeability. Insulin via the protein kinase G type Iα (PKGIα) signaling pathway regulates the balance between contractility and relaxation (permeability) of the podocyte barrier by regulation of the actin cytoskeleton. This mechanism was shown to be disrupted in diabetes. Rho family guanosine-5'-triphosphates (GTPases) are dynamic modulators of the actin cytoskeleton and expressed in cells that form the glomerular filtration barrier. Thus, changes in Rho GTPase activity may affect glomerular permeability to albumin. The present study showed that Rho family GTPases control podocyte migration and permeability. Moreover these processes are regulated by insulin in PKGIα-dependent manner. Modulation of the PKGI-dependent activity of Rac1 and RhoA GTPases with inhibitors or small-interfering RNA impair glomerular permeability to albumin. We also demonstrated this mechanism in obese, insulin-resistant Zucker rats. We propose that PKGIα-Rac1-RhoA crosstalk is necessary in proper organization of the podocyte cytoskeleton and consequently the stabilization of glomerular architecture and regulation of filtration barrier permeability.
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Affiliation(s)
- Patrycja Rachubik
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Maria Szrejder
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland
| | - Marlena Typiak
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Biology, Department of General and Medical Biochemistry, Gdańsk, Poland
| | - Irena Audzeyenka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland
| | - Małgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Stefan Angielski
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland.
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7
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PTEN-induced kinase 1 deficiency alters albumin permeability and insulin signaling in podocytes. J Mol Med (Berl) 2022; 100:903-915. [PMID: 35534645 DOI: 10.1007/s00109-022-02204-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/20/2022] [Accepted: 04/28/2022] [Indexed: 10/18/2022]
Abstract
Alterations of insulin signaling in diabetes are associated with podocyte injury, proteinuria, and renal failure. Insulin stimulates glucose transport to cells and regulates other intracellular processes that are linked to cellular bioenergetics, such as autophagy, gluconeogenesis, fatty acid metabolism, and mitochondrial homeostasis. The dysfunction of mitochondrial dynamics, including mitochondrial fusion, fission, and mitophagy, has been observed in high glucose-treated podocytes and renal cells from patients with diabetes. Previous studies showed that prolonged hyperglycemia is associated with the development of insulin resistance in podocytes, and high glucose-treated podocytes exhibit an increase in mitochondrial fission and decrease in markers of mitophagy. In the present study, we found that deficiency of the main mitophagy protein PTEN-induced kinase 1 (PINK1) significantly increased albumin permeability and hampered glucose uptake to podocytes. We suggest that PINK1 inhibition impairs the insulin signaling pathway, in which lower levels of phosphorylated Akt and membrane fractions of the insulin receptor and glucose transporter-4 were observed. Moreover, PINK1-depleted podocytes exhibited lower podocin and nephrin expression, thus identifying a potential mechanism whereby albumin leakage increases under hyperglycemic conditions when mitophagy is inhibited. In conclusion, we found that PINK1 plays an essential role in insulin signaling and the maintenance of proper permeability in podocytes. Therefore, PINK1 may be a potential therapeutic target for the treatment or prevention of diabetic nephropathy.
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Kulesza T, Typiak M, Rachubik P, Audzeyenka I, Rogacka D, Angielski S, Saleem MA, Piwkowska A. Hyperglycemic environment disrupts phosphate transporter function and promotes calcification processes in podocytes and isolated glomeruli. J Cell Physiol 2022; 237:2478-2491. [PMID: 35150131 DOI: 10.1002/jcp.30700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/20/2022] [Accepted: 02/02/2022] [Indexed: 11/10/2022]
Abstract
Soft tissue calcification is a pathological phenomenon that often occurs in end-stage chronic kidney disease (CKD), which is caused by diabetic nephropathy, among other factors. Hyperphosphatemia present during course of CKD contributes to impairments in kidney function, particularly damages in the glomerular filtration barrier (GFB). Essential elements of the GFB include glomerular epithelial cells, called podocytes. In the present study, we found that human immortalized podocytes express messenger RNA and protein of phosphate transporters, including NaPi 2c (SLC34A3), Pit 1 (SLC20A1), and Pit 2 (SLC20A2), which are sodium-dependent and mediate intracellular phosphate (Pi) transport, and XPR1, which is responsible for extracellular Pi transport. We found that cells that were grown in a medium with a high glucose (HG) concentration (30 mM) expressed less Pit 1 and Pit 2 protein than podocytes that were cultured in a standard glucose medium (11 mM). We found that exposure of the analyzed transporters in the cell membrane of the podocyte is altered by HG conditions. We also found that the activity of tissue nonspecific alkaline phosphatase increased in HG, causing a rise in Pi generation. Additionally, HG led to a reduction of the amount of ectonucleotide pyrophosphatase/phosphodiesterase 1 in the cell membrane of podocytes. The extracellular concentration of pyrophosphate also decreased under HG conditions. These data suggest that a hyperglycemic environment enhances the production of Pi in podocytes and its retention in the extracellular space, which may induce glomerular calcification.
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Affiliation(s)
- Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | | | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland.,Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
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9
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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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10
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Audzeyenka I, Rogacka D, Rachubik P, Typiak M, Rychłowski M, Angielski S, Piwkowska A. The PKGIα-Rac1 pathway is a novel regulator of insulin-dependent glucose uptake in cultured rat podocytes. J Cell Physiol 2021; 236:4655-4668. [PMID: 33244808 DOI: 10.1002/jcp.30188] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 11/09/2022]
Abstract
Insulin plays a major role in regulating glucose homeostasis in podocytes. Protein kinase G type Iα (PKGIα) plays an important role in regulating glucose uptake in these cells. Rac1 signaling plays an essential role in the reorganization of the actin cytoskeleton and is also essential for insulin-stimulated glucose transport. The experiments were conducted using primary rat podocytes. We performed western blot analysis, evaluated small GTPases activity assays, measured radioactive glucose uptake, and performed immunofluorescence imaging to analyze the role of PKGIα-Rac1 signaling in regulating podocyte function. We also utilized a small-interfering RNA-mediated approach to determine the role of PKGIα and Rac1 in regulating glucose uptake in podocytes. The present study investigated the influence of the PKGI pathway on the insulin-dependent regulation of activity and cellular localization of small guanosine triphosphatases in podocytes. We found that the PKGIα-dependent activation of Rac1 signaling induced activation of the PAK/cofilin pathway and increased insulin-mediated glucose uptake in podocytes. The downregulation of PKGIα or Rac1 expression abolished this effect. Rac1 silencing prevented actin remodeling and GLUT4 translocation close to the cell membrane. These data provide evidence that PKGIα-dependent activation of the Rac1 signaling pathways is a novel regulator of insulin-mediated glucose uptake in cultured rat podocytes.
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Affiliation(s)
- Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Michał Rychłowski
- Laboratory of Virus Molecular Biology, University of Gdańsk, Intercollegiate Faculty of Biotechnology, Medical University of Gdańsk, , Gdańsk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Gdańsk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
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11
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Rachubik P, Szrejder M, Audzeyenka I, Rogacka D, Rychłowski M, Angielski S, Piwkowska A. The PKGIα/VASP pathway is involved in insulin- and high glucose-dependent regulation of albumin permeability in cultured rat podocytes. J Biochem 2021; 168:575-588. [PMID: 32484874 PMCID: PMC7763511 DOI: 10.1093/jb/mvaa059] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 05/23/2020] [Indexed: 12/15/2022] Open
Abstract
Podocytes, the principal component of the glomerular filtration barrier, regulate glomerular permeability to albumin via their contractile properties. Both insulin- and high glucose (HG)-dependent activation of protein kinase G type Iα (PKGIα) cause reorganization of the actin cytoskeleton and podocyte disruption. Vasodilator-stimulated phosphoprotein (VASP) is a substrate for PKGIα and involved in the regulation of actin cytoskeleton dynamics. We investigated the role of the PKGIα/VASP pathway in the regulation of podocyte permeability to albumin. We evaluated changes in high insulin- and/or HG-induced transepithelial albumin flux in cultured rat podocyte monolayers. Expression of PKGIα and downstream proteins was confirmed by western blot and immunofluorescence. We demonstrate that insulin and HG induce changes in the podocyte contractile apparatus via PKGIα-dependent regulation of the VASP phosphorylation state, increase VASP colocalization with PKGIα, and alter the subcellular localization of these proteins in podocytes. Moreover, VASP was implicated in the insulin- and HG-dependent dynamic remodelling of the actin cytoskeleton and, consequently, increased podocyte permeability to albumin under hyperinsulinaemic and hyperglycaemic conditions. These results indicate that insulin- and HG-dependent regulation of albumin permeability is mediated by the PKGIα/VASP pathway in cultured rat podocytes. This molecular mechanism may explain podocytopathy and albuminuria in diabetes.
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Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland.,Faculty of Chemistry, Department of Molecular Biotechnology, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland.,Faculty of Chemistry, Department of Molecular Biotechnology, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Michał Rychłowski
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Medical University of Gdańsk, Abrahama 58, 80-307 Gdańsk, Poland
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Wita Stwosza 63, 80-308 Gdańsk, Poland.,Faculty of Chemistry, Department of Molecular Biotechnology, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
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12
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Kulesza T, Piwkowska A. The impact of type III sodium-dependent phosphate transporters (Pit 1 and Pit 2) on podocyte and kidney function. J Cell Physiol 2021; 236:7176-7185. [PMID: 33738792 DOI: 10.1002/jcp.30368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/26/2021] [Accepted: 03/04/2021] [Indexed: 01/07/2023]
Abstract
The sodium-dependent phosphate transporters Pit 1 and Pit 2 belong to the solute carrier 20 (SLC20) family of membrane proteins. They are ubiquitously distributed in the human body. Their crucial function is the intracellular transport of inorganic phosphate (Pi) in the form of H2 PO4 - . They are one of the main elements in maintaining physiological phosphate homeostasis. Recent data have emerged that indicate novel roles of Pit 1 and Pit 2 proteins besides the well-known function of Pi transporters. These membrane proteins are believed to be precise phosphate sensors that mediate Pi-dependent intracellular signaling. They are also involved in insulin signaling and influence cellular insulin sensitivity. In diseases that are associated with hyperphosphatemia, such as diabetes and chronic kidney disease (CKD), disturbances in the function of Pit 1 and Pit 2 are observed. Phosphate transporters from the SLC20 family participate in the calcification of soft tissues, mainly blood vessels, during the course of CKD. The glomerulus and podocytes therein can also be a target of pathological calcification that damages these structures. A few studies have demonstrated the development of Pi-dependent podocyte injury that is mediated by Pit 1 and Pit 2. This paper discusses the role of Pit 1 and Pit 2 proteins in podocyte function, mainly in the context of the development of pathological calcification that disrupts permeability of the renal filtration barrier. We also describe the mechanisms that may contribute to podocyte damage by Pit 1 and Pit 2.
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Affiliation(s)
- Tomasz Kulesza
- 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
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13
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Wang Q, Tian X, Zhou W, Wang Y, Zhao H, Li J, Zhou X, Zhang H, Zhao T, Li P. Protective Role of Tangshen Formula on the Progression of Renal Damage in db/db Mice by TRPC6/Talin1 Pathway in Podocytes. J Diabetes Res 2020; 2020:3634974. [PMID: 33015191 PMCID: PMC7519445 DOI: 10.1155/2020/3634974] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 08/11/2020] [Accepted: 08/29/2020] [Indexed: 12/16/2022] Open
Abstract
Tangshen Formula (TSF) is a Chinese Medicine formula that has been reported to alleviate proteinuria and protect renal function in humans and animals with diabetic kidney disease (DKD). However, little is known about its mechanism in improving proteinuria. The dysregulation of podocyte cell-matrix adhesion has been demonstrated to play an important role in the pathogenesis and progression of proteinuric kidney diseases including DKD. In the present study, the underlying protective mechanism of TSF on podocytes was investigated using the murine model of type 2 DKD db/db mice in vivo and advanced glycation end products (AGEs)-stimulated primary mice podocytes in vitro. Results revealed that TSF treatment could significantly mitigate reduction of podocyte numbers and foot process effacement, reduce proteinuria, and protect renal function in db/db mice. There was a significant increase in expression of transient receptor potential canonical channel 6 (TRPC6) and a decrease in expression of talin1 in podocytes of db/db mice. The results of AGEs-stimulated primary mice podocytes showed increased cell migration and actin-cytoskeleton rearrangement. Moreover, primary mice podocytes stimulated by AGEs displayed an increase in TRPC6-dependent Ca2+ influx, a loss of talin1, and translocation of nuclear factor of activated T cell (NFATC) 2. These dysregulations in mice primary podocytes stimulated by AGEs could be significantly attenuated after TSF treatment. 1-Oleoyl-2-acetyl-sn-glycerol (OAG), a TRPC6 agonist, blocked the protective role of TSF on podocyte cell-matrix adherence. In conclusion, TSF could protect podocytes from injury and reduce proteinuria in DKD, which may be mediated by the regulation of the TRPC6/Talin1 pathway in podocytes.
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Affiliation(s)
- Qian Wang
- Beijing University of Chinese Medicine, Beijing 100029, China
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Wei'e Zhou
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Yan Wang
- Beijing Key Laboratory of Diabetes Research and Care, Center for Endocrine Metabolism and Immune Diseases, Lu He Hospital, Capital Medical University, Beijing 101149, China
| | - Hailing Zhao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jialin Li
- Beijing University of Chinese Medicine, Beijing 100029, China
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Xuefeng Zhou
- Beijing University of Chinese Medicine, Beijing 100029, China
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Haojun Zhang
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Tingting Zhao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Ping Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
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14
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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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15
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Wang Q, Tian X, Wang Y, Wang Y, Li J, Zhao T, Li P. Role of Transient Receptor Potential Canonical Channel 6 (TRPC6) in Diabetic Kidney Disease by Regulating Podocyte Actin Cytoskeleton Rearrangement. J Diabetes Res 2020; 2020:6897390. [PMID: 31998809 PMCID: PMC6964719 DOI: 10.1155/2020/6897390] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/17/2019] [Accepted: 12/23/2019] [Indexed: 01/19/2023] Open
Abstract
Podocyte injury is an important pathogenesis step causing proteinuric kidney diseases such as diabetic kidney disease (DKD). Actin cytoskeleton rearrangement in podocyte induced by multiple pathogenic factors is believed to be the key process resulting in glomerular injury. Many studies have recently shown that transient receptor potential canonical channel 6 (TRPC6) in podocyte plays a critical role in the development and progression of proteinuric kidney disease by regulating its actin cytoskeleton rearrangement. This review is aimed at summarizing the role of TRPC6 on DKD by regulating the podocyte actin cytoskeleton rearrangement, thereby help further broaden our views and understanding on the mechanism of DKD and provide a theoretic basis for exploring new therapeutic targets for DKD patients.
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Affiliation(s)
- Qian Wang
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
- Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Yuyang Wang
- Department of Nephrology, Guang'anmen Hospital of China Academy of Traditional Chinese Medical Sciences, Beijing 100053, China
| | - Yan Wang
- Beijing Key Laboratory of Diabetes Research and Care, Center for Endocrine Metabolism and Immune Diseases, Luhe Hospital, Capital Medical University, Beijing 101149, China
| | - Jialin Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
- Beijing University of Chinese Medicine, Beijing 100029, China
| | - Tingting Zhao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Ping Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
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16
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Rachubik P, Piwkowska A. The role of vasodilator‐stimulated phosphoprotein in podocyte functioning. Cell Biol Int 2019; 43:1092-1101. [DOI: 10.1002/cbin.11149] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 04/06/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research CentrePolish Academy of Sciences Wita Stwosza 63, 80‐308 Gdańsk Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research CentrePolish Academy of Sciences Wita Stwosza 63, 80‐308 Gdańsk Poland
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17
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Dryer SE, Roshanravan H, Kim EY. TRPC channels: Regulation, dysregulation and contributions to chronic kidney disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1041-1066. [PMID: 30953689 DOI: 10.1016/j.bbadis.2019.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/13/2022]
Abstract
Mutations in the gene encoding canonical transient receptor potential-6 (TRPC6) channels result in severe nephrotic syndromes that typically lead to end-stage renal disease. Many but not all of these mutations result in a gain in the function of the resulting channel protein. Since those observations were first made, substantial work has supported the hypothesis that TRPC6 channels can also contribute to progression of acquired (non-genetic) glomerular diseases, including primary and secondary FSGS, glomerulosclerosis during autoimmune glomerulonephritis, and possibly in type-1 diabetes. Their regulation has been extensively studied, especially in podocytes, but also in mesangial cells and other cell types present in the kidney. More recent evidence has implicated TRPC6 in renal fibrosis and tubulointerstitial disease caused by urinary obstruction. Consequently TRPC6 is being extensively investigated as a target for drug discovery. Other TRPC family members are present in kidney. TRPC6 can form a functional heteromultimer with TRPC3, and it has been suggested that TRPC5 may also play a role in glomerular disease progression, although the evidence on this is contradictory. Here we review literature on the expression and regulation of TRPC6, TRPC3 and TRPC5 in various cell types of the vertebrate kidney, the evidence that these channels are dysregulated in disease models, and research showing that knock-out or pharmacological inhibition of these channels can reduce the severity of kidney disease. We also summarize several areas that remain controversial, and some of the large gaps of knowledge concerning the fundamental role of these proteins in regulation of renal function.
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Affiliation(s)
- Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Internal Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA.
| | - Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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18
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Rush BM, Small SA, Stolz DB, Tan RJ. An Efficient Sieving Method to Isolate Intact Glomeruli from Adult Rat Kidney. J Vis Exp 2018. [PMID: 30451231 DOI: 10.3791/58162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Preservation of glomerular structure and function is pivotal in the prevention of glomerulonephritis, a category of kidney disease characterized by proteinuria which can eventually lead to chronic and end-stage renal disease. The glomerulus is a complex apparatus responsible for the filtration of plasma from the body. In disease, structural integrity is lost and allows for the abnormal leakage of plasma contents into the urine. A method to isolate and examine glomeruli in culture is critical for the study of these diseases. In this protocol, an efficient method of retrieving intact glomeruli from adult rat kidneys while conserving structural and morphological characteristics is described. This process is capable of generating high yields of glomeruli per kidney with minimal contamination from other nephron segments. With these glomeruli, injury conditions can be mimicked by incubating them with a variety of chemical toxins, including protamine sulfate, which causes foot process effacement and proteinuria in animal models. Degree of injury can be assessed using transmission electron microscopy, immunofluorescence staining, and western blotting. Nephrin and Wilms Tumor 1 (WT1) levels can also be assessed from these cultures. Due to the ease and flexibility of this protocol, the isolated glomeruli can be utilized as described or in a way that best suits the needs of the researcher to help better study glomerular health and structure in diseased states.
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Affiliation(s)
- Brittney M Rush
- Division of Renal-Electrolyte, Department of Medicine, University of Pittsburgh
| | - Sarah A Small
- Division of Renal-Electrolyte, Department of Medicine, University of Pittsburgh
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh
| | - Roderick J Tan
- Division of Renal-Electrolyte, Department of Medicine, University of Pittsburgh;
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19
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Cuello F, Eaton P. Cysteine-Based Redox Sensing and Its Role in Signaling by Cyclic Nucleotide-Dependent Kinases in the Cardiovascular System. Annu Rev Physiol 2018; 81:63-87. [PMID: 30216743 DOI: 10.1146/annurev-physiol-020518-114417] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oxidant molecules are produced in biological systems and historically have been considered causal mediators of damage and disease. While oxidants may contribute to the pathogenesis of disease, evidence continues to emerge that shows these species also play important regulatory roles in health. A major mechanism of oxidant sensing and signaling involves their reaction with reactive cysteine thiols within proteins, inducing oxidative posttranslational modifications that can couple to altered function to enable homeostatic regulation. Protein kinase A and protein kinase G are regulated by oxidants in this way, and this review focuses on our molecular-level understanding of these events and their role in regulating cardiovascular physiology during health and disease.
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Affiliation(s)
- Friederike Cuello
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany
| | - Philip Eaton
- King's College London, School of Cardiovascular Medicine and Sciences, The British Heart Foundation Centre of Excellence, The Rayne Institute, St. Thomas' Hospital, London SE1 7EH, United Kingdom;
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20
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Tang R, Li ZP, Li MX, Li DW, Ye HB, Su KM, Lin H, Zhang WT. Pro-inflammatory role of transient receptor potential canonical channel 6 in the pathogenesis of chronic rhinosinusitis with nasal polyps. Int Forum Allergy Rhinol 2018; 8:1334-1341. [PMID: 30216703 DOI: 10.1002/alr.22208] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 08/12/2018] [Accepted: 08/23/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND The pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) has not been fully elucidated. This study sought to explore the role and mechanism of transient receptor potential canonical channel 6 (TRPC6) in the pathogenesis of CRSwNP. METHODS Immunohistochemistry (IHC) was employed to evaluate TRPC6 immunolabeling. Real-time polymerase chain reaction (PCR) was conducted to assay TRPC6, stromal interaction molecule 1 (STIM1), and calcium release-activated calcium channel protein 1 (Orai1) messenger RNA (mRNA) levels in 70 patients with CRSwNP, including eosinophilic CRSwNP (ECRSwNP) or non-eosinophilic CRSwNP (nECRSwNP), and 28 control subjects. The concentrations of inflammatory mediators, including interleukin (IL)-1β, IL-5, and IL-25, were assayed by enzyme-linked immunosorbent assay (ELISA). In experiments on human nasal epithelial cell (HNEC) culture and stimulation, the mean fluorescence intensity (MFI) of intracellular Ca2+ was assayed by flow cytometry. Western blotting, real-time PCR, and ELISA were also conducted to assess the effects and mechanisms of TRPC6 activator 1-oleoyl-2-acetyl-glycerol (OAG) and TRPC6 inhibitor 1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl) propoxy]ethyl-1H-imidazole (SKF-96365) on HNECs. RESULTS Upregulation of TRPC6, STIM1, and Orai1 levels was found in CRSwNP patients, particularly in those with ECRSwNP. TRPC6-positive cells correlated positively with the numbers of eosinophils and neutrophils, respectively. Moreover, TRPC6 mRNA was positively correlated with STIM1 and Orai1 mRNA levels. The concentrations of inflammatory mediators, including IL-1β, IL-5, and IL-25, were elevated in CRSwNP, especially in ECRSwNP. In cultured HNECs, TRPC6, STIM1, Orai1, Ca2+ MFI levels, and inflammatory mediators were upregulated by lipopolysaccharide (LPS) and OAG but were inhibited by SKF-96365. CONCLUSION TRPC6 plays a pro-inflammatory role in the pathogenesis of CRSwNP via regulating Ca2+ flow.
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Affiliation(s)
- Ru Tang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Zhi-Peng Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Ming-Xian Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Da-Wei Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Hai-Bo Ye
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Kai-Ming Su
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Hai Lin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Wei-Tian Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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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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Lay AC, Coward RJM. The Evolving Importance of Insulin Signaling in Podocyte Health and Disease. Front Endocrinol (Lausanne) 2018; 9:693. [PMID: 30524379 PMCID: PMC6258712 DOI: 10.3389/fendo.2018.00693] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/05/2018] [Indexed: 12/17/2022] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide, occuring in approximately one-third of diabetic patients. One of the earliest hallmarks of DKD is albuminuria, often occurring following disruptions to the glomerular filtration barrier. Podocytes are highly specialized cells with a central role in filtration barrier maintenance; hence, podocyte dysfunction is a major cause of albuminuria in many settings, including DKD. Numerous studies over the last decade have highlighted the importance of intact podocyte insulin responses in the maintenance of podocyte function. This review summarizes our current perspectives on podocyte insulin signaling, highlighting evidence to support the notion that dysregulated podocyte insulin responses contribute toward podocyte damage, particularly during the pathogenesis of DKD.
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