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Asensio-Lopez MDC, Lax A, Fernandez Del Palacio MJ, Sassi Y, Hajjar RJ, Pascual-Figal DA. Pharmacological inhibition of the mitochondrial NADPH oxidase 4/PKCα/Gal-3 pathway reduces left ventricular fibrosis following myocardial infarction. Transl Res 2018; 199:4-23. [PMID: 29753686 DOI: 10.1016/j.trsl.2018.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/30/2022]
Abstract
Although the initial reparative fibrosis after myocardial infarction (MI) is crucial for preventing rupture of the ventricular wall, an exaggerated fibrotic response and reactive fibrosis outside the injured area are detrimental. Although metformin prevents adverse cardiac remodeling, as well as provides glycemic control, the underlying mechanisms remain poorly documented. This study describes the effect of mitochondrial NADPH oxidase 4 (mitoNox) and protein kinase C-alpha (PKCα) on the cardiac fibrosis and galectin 3 (Gal-3) expression. Randomly rats underwent MI, received metformin or saline solution. A model of biomechanical strain and co-culturewas used to enable cross talk between cardiomyocytes and fibroblasts. Long-term metformin treatment after MIwas associated with (1) a reduction in myocardial fibrosis and Gal-3 levels; (2) an increase in adenosine monophosphate-activated protein kinase (AMPK) α1/α2 levels; and (3) an inhibition of both mRNA expression and enzymatic activities of mitoNox and PKCα. These findings were replicated in the cellular model, where the silencing of AMPK expression blocked the ability of metformin to protect cardiomyocytes from strain. The use of specific inhibitors or small interference RNA provided evidence that PKCα is downstream of mitoNox, and that the activation of this pathway results in Gal-3 upregulation.The Gal-3 secreted by cardiomyocytes has a paracrine effect on cardiac fibroblasts, inducing their activation. In conclusion, a metformin-induced increase in AMPK improves myocardial remodeling post-MI, which is related to the inhibition of the mitoNox/PKCα/Gal-3 pathway. Manipulation of this pathway might offer new therapeutic options against adverse cardiac remodeling, in terms of preventing the activation of the present fibroblast population.
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Affiliation(s)
| | - Antonio Lax
- Biomedical Research Institute Virgen de la Arrixaca (IMIB-Arrixaca), University of Murcia, Murcia, Spain.
| | | | - Yassine Sassi
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Roger J Hajjar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Domingo A Pascual-Figal
- Cardiology Department, Clinic and Universitary Hospital Virgen de la Arrixaca, Murcia, Spain; CIBER in Cardiovascular Diseases (CIBERCV), Madrid, Spain
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Yang Q, Wu FR, Wang JN, Gao L, Jiang L, Li HD, Ma Q, Liu XQ, Wei B, Zhou L, Wen J, Ma TT, Li J, Meng XM. Nox4 in renal diseases: An update. Free Radic Biol Med 2018; 124:466-472. [PMID: 29969717 DOI: 10.1016/j.freeradbiomed.2018.06.042] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 01/14/2023]
Abstract
Reactive oxygen species derived from NADPH oxidase contribute to a wide variety of renal diseases. Nox4, the major NADPH isoform in kidney, produces mainly H2O2 that regulates physiological functions. Nox4 contributes to redox processes involved in diabetic nephropathy, acute kidney injury, obstructive nephropathy, hypertensive nephropathy, renal cell carcinoma and other renal diseases by activating multiple signaling pathways. Although Nox4 is found in a variety of cell types, including epithelial cells, podocytes, mesangial cells, endothelial cells and fibroblasts, its role is not clear and even controversial. In some conditions, Nox4 protects cells by promoting cell survival in response to harmful stimuli. In other scenarios it induces cell apoptosis, inflammation or fibrogenesis. This functional variability may be attributed to distinct cell types, subcellular localization, molecular concentrations, disease type or stage, and other factors yet unexplored. In this setting, we reviewed the function and mechanism of Nox4 in renal diseases, highlighted the contradictions in Nox4 literature, and discussed promising therapeutic strategies targeting Nox4 in the treatment of certain types of renal diseases.
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Affiliation(s)
- Qin Yang
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Fan-Rong Wu
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Jia-Nan Wang
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Li Gao
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Ling Jiang
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Hai-Di Li
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Qiuying Ma
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Xue-Qi Liu
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Biao Wei
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Luyu Zhou
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China
| | - Jiagen Wen
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China; Anhui Institute of Innovative Drugs, Anhui, China; Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui, 230032, China
| | - Tao Tao Ma
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China; Anhui Institute of Innovative Drugs, Anhui, China; Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui, 230032, China
| | - Jun Li
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China; Anhui Institute of Innovative Drugs, Anhui, China; Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui, 230032, China
| | - Xiao-Ming Meng
- School of Pharmacy, Anhui Medical University, Hefei, Anhui, China; Anhui Institute of Innovative Drugs, Anhui, China; Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui, 230032, China.
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Bai X, Geng J, Li X, Wan J, Liu J, Zhou Z, Liu X. Long Noncoding RNA LINC01619 Regulates MicroRNA-27a/Forkhead Box Protein O1 and Endoplasmic Reticulum Stress-Mediated Podocyte Injury in Diabetic Nephropathy. Antioxid Redox Signal 2018; 29:355-376. [PMID: 29334763 DOI: 10.1089/ars.2017.7278] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
AIMS Altered activities of long noncoding RNAs (lncRNAs) have been implicated in the regulation of microRNAs. microRNA-27a (miR-27a) upregulation has been shown to induce endoplasmic reticulum (ER) stress podocyte injury in diabetic nephropathy (DN). Herein, we aim to interrogate the mutually regulated network of miR-27a with long intergenic noncoding RNA 1619 (LINC01619) and the target gene. RESULTS LINC01619 downregulation was found in human DN renal biopsy tissues and contributed to proteinuria and diminished renal function. LINC01619 was expressed in podocyte cytoplasm and involved in ER stress signaling pathway. LINC01619 exerted biological function by serving as a "sponge" for miR-27a, which negatively targeted forkhead box protein O1 (FOXO1) and activated ER stress. In diabetic rats and high-glucose cultured podocytes, LINC01619 triggered oxidative stress and podocyte injuries as demonstrated by increased apoptosis, diffuse podocyte foot process effacement, and decreased renal function. Innovation and Conclusion: This study demonstrates that LINC01619 functions as a competing endogenous RNA and regulates miR-27a/FOXO1-mediated ER stress and podocyte injury in DN. Antioxid. Redox Signal. 29, 355-376.
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Affiliation(s)
- Xiaoyan Bai
- 1 Division of Nephrology, State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Jian Geng
- 2 Department of Pathology, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Xiao Li
- 3 Department of Emergency, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Jiao Wan
- 1 Division of Nephrology, State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Jixing Liu
- 1 Division of Nephrology, State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Zhanmei Zhou
- 1 Division of Nephrology, State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Guangdong Provincial Institute of Nephrology, Nanfang Hospital, Southern Medical University , Guangzhou, People's Republic of China
| | - Xiaoting Liu
- 4 Department of Pathology, King Medical Diagnostics Center , Guangzhou, People's Republic of China
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Gurukar MSA, Chilkunda ND. Morus alba Leaf Bioactives Modulate Peroxisome Proliferator Activated Receptor γ in the Kidney of Diabetic Rat and Impart Beneficial Effect. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:7923-7934. [PMID: 29969905 DOI: 10.1021/acs.jafc.8b01357] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Peroxisome proliferator activated receptor gamma (PPARγ) is a ligand-activated nuclear receptor that can be activated or repressed by several exogenous and endogenous ligands and acts by modulating genes that regulate lipid, glucose, and insulin homeostasis. In kidney, PPARγ is involved in normal kidney development and other physiological functions. In our earlier report, we showed that feeding Morus alba leaves to experimental diabetic rats ameliorated diabetic nephropathy and significantly decreased microalbuminuria. In this paper, we have attempted to look into the molecular mechanism involving PPARγ modulation by mulberry leaf bioactive compounds by in vitro and in vivo methods and its impact on key inflammatory markers. In vitro assay by TR-FRET suggested that mulberry leaf extracts can serve as a putative modulator of PPARγ. High glucose conditions in vitro and in vivo increased PPARγ levels, which were ameliorated by mulberry leaves or their extracts. Interestingly, PPARγ was significantly phosphorylated at Ser112 by upstream kinases ERK42/44 in kidney of diabetic animals on feeding mulberry leaves. In vitro studies using MDCK cell line revealed that increased Ser112 phosphorylation was observed when cells were treated with bound phenolic acid rich extract but not with free phenolic acid rich extracts. HPLC analysis and bioassay-guided activity revealed that coumaric acid was the bioactive molecule within bound phenolic acid rich extract that was responsible for increased ERK42/44-mediated phosphorylation at Ser112. Furthermore, mulberry leaf bioactive compounds showed beneficial effect on the tested inflammatory markers.
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Affiliation(s)
- Mulluru Somasundara Abignan Gurukar
- Department of Molecular Nutrition , CSIR-CFTRI Mysuru , 570 020 Karnataka India
- Academy of Scientific and Innovative Research (AcSIR) , CSIR-CFTRI campus , Mysuru , 570 020 , Karnataka India
| | - Nandini D Chilkunda
- Department of Molecular Nutrition , CSIR-CFTRI Mysuru , 570 020 Karnataka India
- Academy of Scientific and Innovative Research (AcSIR) , CSIR-CFTRI campus , Mysuru , 570 020 , Karnataka India
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Qiao X, Wang L, Wang Y, Su X, Qi Y, Fan Y, Peng Z. Intermedin inhibits unilateral ureteral obstruction-induced oxidative stress via NADPH oxidase Nox4 and cAMP-dependent mechanisms. Ren Fail 2018; 39:652-659. [PMID: 28805491 PMCID: PMC6447914 DOI: 10.1080/0886022x.2017.1361839] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
NADPH oxidase Nox4-derived reactive oxygen species (ROS) play important roles in renal fibrosis. Our previous study demonstrated that intermedin (IMD) alleviated unilateral ureteral obstruction (UUO)-induced renal fibrosis by inhibition of ROS. However, the precise mechanisms remain unclear. Herein, we investigated the effect of IMD on Nox4 expression and NADPH oxidase activity in rat UUO model, and explored if these effect were achieved through cAMP-PKA pathway, the important post-receptor signal transduction pathway of IMD, in TGF-β1-stimulated rat proximal tubular cell (NRK-52E). Renal fibrosis was induced by UUO. NRK-52E was exposed to rhTGF-β1 to establish an in vitro model of fibrosis. IMD was overexpressed in the kidney and in NRK-52E by IMD gene transfer. We studied UUO-induced ROS by measuring dihydroethidium levels and lipid peroxidation end-product 4-hydroxynonenal expression. Nox4 expression in the obstructed kidney of UUO rat or in TGF-β1-stimulated NRK-52E was measured by quantitative RT-PCR and Western blotting. We analyzed NADPH oxidase activity using a lucigenin-enhanced chemiluminescence system. We showed that UUO-stimulated ROS production was remarkably attenuated by IMD gene transfer. IMD overexpression inhibited UUO-induced up-regulation of Nox4 and activation of NADPH oxidase. Consistent with in vivo results, TGF-β1-stimulated increase in Nox4 expression and NADPH oxidase activity was blocked by IMD. In NRK-52E, these beneficial effects of IMD were abolished by pretreatment with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide hydrochloride (H-89), a PKA inhibitor, and mimicked by a cell-permeable cAMP analog dibutyl-cAMP. Our results indicate that IMD exerts anti-oxidant effects by inhibition of Nox4, and the effect can be mediated by cAMP-PKA pathway.
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Affiliation(s)
- Xi Qiao
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Lihua Wang
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yanhong Wang
- c Department of Microbiology and Immunology , Shanxi Medical University , Taiyuan , Shanxi , China
| | - Xiaole Su
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yue Qi
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Yun Fan
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
| | - Zhiqiang Peng
- a Department of Nephrology , Second Hospital of Shanxi Medical University , Shanxi , China.,b Shanxi Kidney Disease Institute , Shanxi , China
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Comprehensive renoprotective effects of ipragliflozin on early diabetic nephropathy in mice. Sci Rep 2018; 8:4029. [PMID: 29507299 PMCID: PMC5838225 DOI: 10.1038/s41598-018-22229-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/19/2018] [Indexed: 12/20/2022] Open
Abstract
Clinical and experimental studies have shown that sodium glucose co-transporter 2 inhibitors (SGLT2i) contribute to the prevention of diabetic kidney disease progression. In order to clarify its pharmacological effects on the molecular mechanisms underlying the development of diabetic kidney disease, we administered different doses of the SGLT2i, ipragliflozin, to type 2 diabetic mice. A high-dose ipragliflozin treatment for 8 weeks lowered blood glucose levels and reduced urinary albumin excretion. High- and low-dose ipragliflozin both inhibited renal and glomerular hypertrophy, and reduced NADPH oxidase 4 expression and subsequent oxidative stress. Analysis of glomerular phenotypes using glomeruli isolation demonstrated that ipragliflozin preserved podocyte integrity and reduced oxidative stress. Regarding renal tissue hypoxia, a short-term ipragliflozin treatment improved oxygen tension in the kidney cortex, in which SGLT2 is predominantly expressed. We then administered ipragliflozin to type 1 diabetic mice and found that high- and low-dose ipragliflozin both reduced urinary albumin excretion. In conclusion, we confirmed dose-dependent differences in the effects of ipragliflozin on early diabetic nephropathy in vivo. Even low-dose ipragliflozin reduced renal cortical hypoxia and abnormal hemodynamics in early diabetic nephropathy. In addition to these effects, high-dose ipragliflozin exerted renoprotective effects by reducing oxidative stress in tubular epithelia and glomerular podocytes.
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Yu SMW, Bonventre JV. Acute Kidney Injury and Progression of Diabetic Kidney Disease. Adv Chronic Kidney Dis 2018; 25:166-180. [PMID: 29580581 DOI: 10.1053/j.ackd.2017.12.005] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/15/2017] [Accepted: 12/22/2017] [Indexed: 12/23/2022]
Abstract
Diabetic kidney disease, commonly termed diabetic nephropathy (DN), is the most common cause of end-stage kidney disease (ESKD) worldwide. The characteristic histopathology of DN includes glomerular basement membrane thickening, mesangial expansion, nodular glomerular sclerosis, and tubulointerstitial fibrosis. Diabetes is associated with a number of metabolic derangements, such as reactive oxygen species overproduction, hypoxic state, mitochondrial dysfunction, and inflammation. In the past few decades, our knowledge of DN has advanced considerably although much needs to be learned. The traditional paradigm of glomerulus-centered pathophysiology has expanded to the tubule-interstitium, the immune response and inflammation. Biomarkers of proximal tubule injury have been shown to correlate with DN progression, independent of traditional glomerular injury biomarkers such as albuminuria. In this review, we summarize mechanisms of increased susceptibility to acute kidney injury in diabetes mellitus and the roles played by many kidney cell types to facilitate maladaptive responses leading to chronic and end-stage kidney disease.
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Abstract
The mechanism by which TSC2 inactivation or deficiency contributes to the pathology of tuberous sclerosis complex (TSC) is not fully clear. We show that renal angiomyolipomas from TSC patients and kidney cortex from Tsc2+/− mice exhibit elevated levels of reactive oxygen species (ROS). Downregulation of tuberin (protein encoded by TSC2 gene) in renal proximal tubular epithelial cells significantly increased ROS concomitant with enhanced Nox4. Similarly, we found elevated levels of Nox4 in the renal cortex of Tsc2+/− mice and in the renal angiomyolipomas from TSC patients. Tuberin deficiency is associated with activation of mTORC1. Rapamycin, shRNAs targeting raptor, or inhibition of S6 kinase significantly inhibited the expression of Nox4, resulting in attenuation of production of ROS in tuberin-downregulated proximal tubular epithelial cells. In contrast, activation of mTORC1 increased Nox4 and ROS. These results indicate that Nox4 may be a potential target for tuberin-deficiency-derived diseases. Using a xenograft model from tuberin-null tubular cells in nude mice, both anti-sense Nox4 and GKT137831, a specific inhibitor of Nox1/4, significantly inhibited the tumor growth. Thus, our results demonstrate the presence of an antagonistic relationship between tuberin and Nox4 to drive oncogenesis in the tuberin deficiency syndrome and identify Nox4 as a target to develop a therapy for TSC.
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Maity S, Bera A, Ghosh-Choudhury N, Das F, Kasinath BS, Choudhury GG. microRNA-181a downregulates deptor for TGFβ-induced glomerular mesangial cell hypertrophy and matrix protein expression. Exp Cell Res 2018; 364:5-15. [PMID: 29397070 DOI: 10.1016/j.yexcr.2018.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/16/2018] [Indexed: 02/06/2023]
Abstract
TGFβ contributes to mesangial cell hypertrophy and matrix protein increase in various kidney diseases including diabetic nephropathy. Deptor is an mTOR-interacting protein and suppresses mTORC1 and mTORC2 activities. We have recently shown that TGFβ-induced inhibition of deptor increases the mTOR activity. The mechanism by which TGFβ regulates deptor expression is not known. Here we identify deptor as a target of the microRNA-181a. We show that in mesangial cells, TGFβ increases the expression of miR-181a to downregulate deptor. Decrease in deptor augments mTORC2 activity, resulting in phosphorylation/activation of Akt kinase. Akt promotes inactivating phosphorylation of PRAS40 and tuberin, leading to stimulation of mTORC1. miR-181a-mimic increased mTORC1 and C2 activities, while anti-miR-181a inhibited them. mTORC1 controls protein synthesis via phosphorylation of translation initiation and elongation suppressors 4EBP-1 and eEF2 kinase. TGFβ-stimulated miR-181a increased the phosphorylation of 4EBP-1 and eEF2 kinase, resulting in their inactivation. miR-181a-dependent inactivation of eEF2 kinase caused dephosphorylation of eEF2. Consequently, miR-181a-mimic increased protein synthesis and hypertrophy of mesangial cells similar to TGFβ. Anti-miR-181a blocked these events in a deptor-dependent manner. Finally, TGFβ-miR-181a-driven deptor downregulation increased the expression of fibronectin. Our results identify a novel mechanism involving miR-181a-driven deptor downregulation, which contributes to mesangial cell pathologies in renal complications.
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Affiliation(s)
- Soumya Maity
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Amit Bera
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, UT Health San Antonio, TX, United States
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Research Center, South Texas Veterans Health Care System, San Antonio, TX, United States.
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Hu F, Xue M, Li Y, Jia YJ, Zheng ZJ, Yang YL, Guan MP, Sun L, Xue YM. Early Growth Response 1 (Egr1) Is a Transcriptional Activator of NOX4 in Oxidative Stress of Diabetic Kidney Disease. J Diabetes Res 2018; 2018:3405695. [PMID: 29854821 PMCID: PMC5944279 DOI: 10.1155/2018/3405695] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/11/2017] [Accepted: 11/21/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND NADPH oxidase 4 (NOX4) plays a major role in renal oxidative stress of diabetic kidney disease (DKD). NOX4 was significantly increased in Egr1-expressing fibroblasts, but the relationship between Egr1 and NOX4 in DKD is unclear. METHODS For the evaluation of the potential relationship between Egr1 and NOX4, both were detected in HFD/STZ-induced mice and HK-2 cells treated with TGF-β1. Then, changes in NOX4 expression were detected in HK-2 cells and mice with overexpression and knockdown of Egr1. The direct relationship between Egr1 and NOX4 was explored via chromatin immunoprecipitation (ChIP). RESULTS We found increased levels of Egr1, NOX4, and α-SMA in the kidney cortices of diabetic mice and in TGF-β1-treated HK-2 cells. Overexpression or silencing of Egr1 in HK-2 cells could upregulate or downregulate NOX4 and α-SMA. ChIP assays revealed that TGF-β1 induced Egr1 to bind to the NOX4 promoter. Finally, Egr1 overexpression or knockdown in diabetic mice could upregulate or downregulate the expression of NOX4 and ROS, and α-SMA was also changed. CONCLUSION Our study provides strong evidence that Egr1 is a transcriptional activator of NOX4 in oxidative stress of DKD. Egr1 contributes to DKD by enhancing EMT, in part by targeting NOX4.
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Affiliation(s)
- Fang Hu
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Department of Endocrinology and Metabolism, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Meng Xue
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Department of Endocrinology and Metabolism, Shenzhen People's Hospital, Second Affiliated Hospital of Jinan University, Shenzhen, Guangdong, China
| | - Yang Li
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
- Department of Geriatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yi-Jie Jia
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zong-Ji Zheng
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yan-Lin Yang
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Mei-Ping Guan
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Liao Sun
- Department of Endocrinology and Metabolism, The Fifth Affiliated Hospital Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Yao-Ming Xue
- Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
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Bera A, Das F, Ghosh-Choudhury N, Mariappan MM, Kasinath BS, Ghosh Choudhury G. Reciprocal regulation of miR-214 and PTEN by high glucose regulates renal glomerular mesangial and proximal tubular epithelial cell hypertrophy and matrix expansion. Am J Physiol Cell Physiol 2017; 313:C430-C447. [PMID: 28701356 PMCID: PMC5668576 DOI: 10.1152/ajpcell.00081.2017] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 02/06/2023]
Abstract
Aberrant expression of microRNAs (miRs) contributes to diabetic renal complications, including renal hypertrophy and matrix protein accumulation. Reduced expression of phosphatase and tensin homolog (PTEN) by hyperglycemia contributes to these processes. We considered involvement of miR in the downregulation of PTEN. In the renal cortex of type 1 diabetic mice, we detected increased expression of miR-214 in association with decreased levels of PTEN and enhanced Akt phosphorylation and fibronectin expression. Mesangial and proximal tubular epithelial cells exposed to high glucose showed augmented expression of miR-214. Mutagenesis studies using 3'-UTR of PTEN in a reporter construct revealed PTEN as a direct target of miR-214, which controls its expression in both of these cells. Overexpression of miR-214 decreased the levels of PTEN and increased Akt activity similar to high glucose and lead to phosphorylation of its substrates glycogen synthase kinase-3β, PRAS40, and tuberin. In contrast, quenching of miR-214 inhibited high-glucose-induced Akt activation and its substrate phosphorylation; these changes were reversed by small interfering RNAs against PTEN. Importantly, respective expression of miR-214 or anti-miR-214 increased or decreased the mammalian target of rapamycin complex 1 (mTORC1) activity induced by high glucose. Furthermore, mTORC1 activity was controlled by miR-214-targeted PTEN via Akt activation. In addition, neutralization of high-glucose-stimulated miR-214 expression significantly inhibited cell hypertrophy and expression of the matrix protein fibronectin. Finally, the anti-miR-214-induced inhibition of these processes was reversed by the expression of constitutively active Akt kinase and hyperactive mTORC1. These results uncover a significant role of miR-214 in the activation of mTORC1 that contributes to high-glucose-induced mesangial and proximal tubular cell hypertrophy and fibronectin expression.
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Affiliation(s)
- Amit Bera
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Department of Pathology, UT Health San Antonio, San Antonio, Texas; and
| | | | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, San Antonio, Texas;
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas
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Dlamini Z, Mokoena F, Hull R. Abnormalities in alternative splicing in diabetes: therapeutic targets. J Mol Endocrinol 2017; 59:R93-R107. [PMID: 28716821 DOI: 10.1530/jme-17-0049] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 05/30/2017] [Indexed: 12/19/2022]
Abstract
Diabetes mellitus (DM) is a non-communicable, metabolic disorder that affects 416 million individuals worldwide. Type 2 diabetes contributes to a vast 85-90% of the diabetes incidences while 10-15% of patients suffer from type 1 diabetes. These two predominant forms of DM cause a significant loss of functional pancreatic β-cell mass causing different degrees of insulin deficiency, most likely, due to increased β-cell apoptosis. Treatment options involve the use of insulin sensitisers, α-glucosidase inhibitors, and β-cell secretagogues which are often expensive, limited in efficacy and carry detrimental adverse effects. Cost-effective options for treatment exists in the form of herbal drugs, however, scientific validations of these widely used medicinal plants are still underway. Alternative splicing (AS) is a co-ordinated post-transcriptional process in which a single gene generates multiple mRNA transcripts which results in increased amounts of functionally different protein isoforms and in some cases aberrant splicing leads to metabolic disease. In this review, we explore the association of AS with metabolic alterations in DM and the biological significance of the abnormal splicing of some pathogenic diabetes-related genes. An understanding of the molecular mechanism behind abnormally spliced transcripts will aid in the development of new diagnostic, prognostic and therapeutic tools.
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Affiliation(s)
- Zodwa Dlamini
- ResearchInnovation & Engagements Portfolio, Mangosuthu University of Technology, Durban, South Africa
| | - Fortunate Mokoena
- ResearchInnovation & Engagements Portfolio, Mangosuthu University of Technology, Durban, South Africa
| | - Rodney Hull
- ResearchInnovation & Engagements Portfolio, Mangosuthu University of Technology, Durban, South Africa
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63
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Zhang L, Zhang Q, Liu S, Chen Y, Li R, Lin T, Yu C, Zhang H, Huang Z, Zhao X, Tan X, Li Z, Ye Z, Ma J, Zhang B, Wang W, Shi W, Liang X. DNA methyltransferase 1 may be a therapy target for attenuating diabetic nephropathy and podocyte injury. Kidney Int 2017; 92:140-153. [PMID: 28318634 DOI: 10.1016/j.kint.2017.01.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/21/2016] [Accepted: 01/05/2017] [Indexed: 01/19/2023]
Affiliation(s)
- Li Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | | | - Shuangxin Liu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yuanhan Chen
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ruizhao Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ting Lin
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Chunping Yu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Hong Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhongshun Huang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xinchen Zhao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China; Southern Medical University, Guangzhou, China
| | - Xiaofan Tan
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhuo Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zhiming Ye
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jianchao Ma
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Bin Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Wenjian Wang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Wei Shi
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Xinling Liang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
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64
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Wan J, Hou X, Zhou Z, Geng J, Tian J, Bai X, Nie J. WT1 ameliorates podocyte injury via repression of EZH2/β-catenin pathway in diabetic nephropathy. Free Radic Biol Med 2017; 108:280-299. [PMID: 28315733 DOI: 10.1016/j.freeradbiomed.2017.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/26/2017] [Accepted: 03/13/2017] [Indexed: 10/20/2022]
Abstract
Epigenetic modulation of podocyte injury plays a pivotal role in diabetic nephropathy (DN). Wilm's tumor 1 (WT1) has been found to have opposing roles with β-catenin in podocyte biology. Herein, we asked whether the histone methyltransferase enzyme enhancer of zeste homolog 2 (EZH2) promotes WT1-induced podocyte injury via β-catenin activation and the underlying mechanisms. We found that WT1 antagonized EZH2 and ameliorated β-catenin-mediated podocyte injury as demonstrated by attenuated podocyte mesenchymal transition, maintenance of podocyte architectural integrity, decreased podocyte apoptosis and oxidative stress. Further, we provided mechanistical evidence that EZH2 was required in WT1-mediated β-catenin inactivation via repression of secreted frizzled-related protein 1 (SFRP-1), a Wnt antagonist. Moreover, EZH2-mediated silencing of SFRP-1 was due to increased histone 3 lysine 27 trimethylation (H3K27me3) on its promoter region. WT1 favored renal function and decreased podocyte injury in diabetic rats and DN patients. Notably, WT1 exhibited clinical and biological relevance as it was linked to dropped serum creatinine, decreased proteinuria and elevated estimated glomerular filtration rate (eGFR). We propose an epigenetic process via the WT1/EZH2/β-catenin axis in attenuating podocyte injury in DN. Targeting WT1 and EZH2 could be potential therapeutic approaches for DN.
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Affiliation(s)
- Jiao Wan
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China
| | - Xiaoyan Hou
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China
| | - Zhanmei Zhou
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China
| | - Jian Geng
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, PR China
| | - Jianwei Tian
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China
| | - Xiaoyan Bai
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China.
| | - Jing Nie
- Division of Nephrology, Nanfang Hospital, Southern Medical University, National Clinical Research Center for Kidney Disease, State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Guangzhou, Guangdong, PR China.
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65
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Hernández-Saavedra D, Sanders L, Perez MJ, Kosmider B, Smith LP, Mitchell JD, Yoshida T, Tuder RM. RTP801 Amplifies Nicotinamide Adenine Dinucleotide Phosphate Oxidase-4-Dependent Oxidative Stress Induced by Cigarette Smoke. Am J Respir Cell Mol Biol 2017; 56:62-73. [PMID: 27556956 DOI: 10.1165/rcmb.2016-0144oc] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Tobacco smoke (TS) causes chronic obstructive pulmonary disease, including chronic bronchitis, emphysema, and asthma. Rtp801, an inhibitor of mechanistic target of rapamycin, is induced by oxidative stress triggered by TS. Its up-regulation drives lung susceptibility to TS injury by enhancing inflammation and alveolar destruction. We postulated that Rtp801 is not only increased by reactive oxygen species (ROS) in TS but also instrumental in creating a feedforward process leading to amplification of endogenous ROS generation. We used cigarette smoke extract (CSE) to model the effect of TS in wild-type (Wt) and knockout (KO-Rtp801) mouse lung fibroblasts (MLF). The production of superoxide anion in KO-Rtp801 MLF was lower than that in Rtp801 Wt cells after CSE treatment, and it was inhibited in Wt MLF by silencing nicotinamide adenine dinucleotide phosphate oxidase-4 (Nox4) expression with small interfering Nox4 RNA. We observed a cytoplasmic location of ROS formation by real-time redox changes using reduction-oxidation-sensitive green fluorescent protein profluorescent probes. Both the superoxide production and the increase in the cytoplasmic redox were inhibited by apocynin. Reduction in the activity of Sod and decreases in the expression of Sod2 and Gpx1 genes were associated with Rtp801 CSE induction. The ROS produced by Nox4 in conjunction with the decrease in cellular antioxidant enzymatic defenses may account for the observed cytoplasmic redox changes and cellular damage caused by TS.
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Affiliation(s)
- Daniel Hernández-Saavedra
- 1 Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine.,2 Cardiovascular Pulmonary Research Laboratories, Department of Pediatrics, and
| | - Linda Sanders
- 1 Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine
| | - Mario J Perez
- 1 Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine
| | - Beata Kosmider
- 3 Department of Medicine, National Jewish Health, Denver, Colorado; and
| | - Lynelle P Smith
- 1 Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine
| | - John D Mitchell
- 4 Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Toshinori Yoshida
- 5 Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Rubin M Tuder
- 1 Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine
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66
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Zhang X, Lerman LO. The metabolic syndrome and chronic kidney disease. Transl Res 2017; 183:14-25. [PMID: 28025032 PMCID: PMC5393937 DOI: 10.1016/j.trsl.2016.12.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/22/2016] [Accepted: 12/02/2016] [Indexed: 02/07/2023]
Abstract
The metabolic syndrome (MetS) is a cluster of cardiovascular risk factors including insulin resistance (IR), dyslipidemia, and hypertension, which may also foster development of chronic kidney disease. The mechanisms of MetS-induced kidney disease are not fully understood. The purpose of this review is to summarize recent discoveries regarding the impact of MetS on the kidney, particularly on the renal microvasculature and cellular mitochondria. Fundamental manifestations of MetS include IR and adipose tissue expansion, the latter promoting chronic inflammation and oxidative stress that exacerbate IR. Those in turn can elicit various kidney injurious events through endothelial dysfunction, activation of the renin-angiotensin-aldosterone system, and adipokine imbalance. Inflammation and IR are also major contributors to microvascular remodeling and podocyte injury. Hence, these events may result in hypertension, albuminuria, and parenchymal damage. In addition, dyslipidemia and excessive nutrient availability may impair mitochondrial function and thereby promote progression of kidney cell damage. Elucidation of the link between MetS and kidney injury may help develop preventative measures and possibly novel therapeutic targets to alleviate and avert development of renal manifestations.
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Affiliation(s)
- Xin Zhang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn.
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67
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Das F, Ghosh-Choudhury N, Venkatesan B, Kasinath BS, Ghosh Choudhury G. PDGF receptor-β uses Akt/mTORC1 signaling node to promote high glucose-induced renal proximal tubular cell collagen I (α2) expression. Am J Physiol Renal Physiol 2017; 313:F291-F307. [PMID: 28424212 DOI: 10.1152/ajprenal.00666.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/11/2017] [Accepted: 04/12/2017] [Indexed: 01/28/2023] Open
Abstract
Increased expression of PDGF receptor-β (PDGFRβ) has been shown in renal proximal tubules in mice with diabetes. The core molecular network used by high glucose to induce proximal tubular epithelial cell collagen I (α2) expression is poorly understood. We hypothesized that activation of PDGFRβ by high glucose increases collagen I (α2) production via the Akt/mTORC1 signaling pathway in proximal tubular epithelial cells. Using biochemical and molecular biological techniques, we investigated this hypothesis. We show that high glucose increases activating phosphorylation of the PDGFRβ, resulting in phosphorylation of phosphatidylinositol 3-kinase. A specific inhibitor, JNJ-10198409, and small interfering RNAs targeting PDGFRβ blocked this phosphorylation without having any effect on MEK/Erk1/2 activation. We also found that PDGFRβ regulates high glucose-induced Akt activation, its targets tuberin and PRAS40 phosphorylation, and finally, mTORC1 activation. Furthermore, inhibition of PDGFRβ suppressed high glucose-induced expression of collagen I (α2) in proximal tubular cells. Importantly, expression of constitutively active Akt or mTORC1 reversed these processes. As a mechanism, we found that JNJ and PDGFRβ knockdown inhibited high glucose-stimulated Hif1α expression. Furthermore, overexpression of Hif1α restored expression of collagen I (α2) that was inhibited by PDGFRβ knockdown in high glucose-stimulated cells. Finally, we show increased phosphorylation of PDGFRβ and its association with Akt/mTORC1 activation, Hif1α expression, and elevated collagen I (α2) levels in the renal cortex of mice with diabetes. Our results identify PDGFRβ as a driver in activating Akt/mTORC1 nexus for high glucose-mediated expression of collagen I (α2) in proximal tubular epithelial cells, which contributes to tubulointerstitial fibrosis in diabetic nephropathy.
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Affiliation(s)
- Falguni Das
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas.,Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Balachandar Venkatesan
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Balakuntalam S Kasinath
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas.,VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; .,VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas.,Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas; and
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68
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Salatto CT, Miller RA, Cameron KO, Cokorinos E, Reyes A, Ward J, Calabrese MF, Kurumbail RG, Rajamohan F, Kalgutkar AS, Tess DA, Shavnya A, Genung NE, Edmonds DJ, Jatkar A, Maciejewski BS, Amaro M, Gandhok H, Monetti M, Cialdea K, Bollinger E, Kreeger JM, Coskran TM, Opsahl AC, Boucher GG, Birnbaum MJ, DaSilva-Jardine P, Rolph T. Selective Activation of AMPK β1-Containing Isoforms Improves Kidney Function in a Rat Model of Diabetic Nephropathy. J Pharmacol Exp Ther 2017; 361:303-311. [PMID: 28289077 DOI: 10.1124/jpet.116.237925] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 03/06/2017] [Indexed: 12/16/2022] Open
Abstract
Diabetic nephropathy remains an area of high unmet medical need, with current therapies that slow down, but do not prevent, the progression of disease. A reduced phosphorylation state of adenosine monophosphate-activated protein kinase (AMPK) has been correlated with diminished kidney function in both humans and animal models of renal disease. Here, we describe the identification of novel, potent, small molecule activators of AMPK that selectively activate AMPK heterotrimers containing the β1 subunit. After confirming that human and rodent kidney predominately express AMPK β1, we explore the effects of pharmacological activation of AMPK in the ZSF1 rat model of diabetic nephropathy. Chronic administration of these direct activators elevates the phosphorylation of AMPK in the kidney, without impacting blood glucose levels, and reduces the progression of proteinuria to a greater degree than the current standard of care, angiotensin-converting enzyme inhibitor ramipril. Further analyses of urine biomarkers and kidney tissue gene expression reveal AMPK activation leads to the modulation of multiple pathways implicated in kidney injury, including cellular hypertrophy, fibrosis, and oxidative stress. These results support the need for further investigation into the potential beneficial effects of AMPK activation in kidney disease.
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Affiliation(s)
- Christopher T Salatto
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Russell A Miller
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Kimberly O Cameron
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Emily Cokorinos
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Allan Reyes
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Jessica Ward
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Matthew F Calabrese
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Ravi G Kurumbail
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Francis Rajamohan
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Amit S Kalgutkar
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - David A Tess
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Andre Shavnya
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Nathan E Genung
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - David J Edmonds
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Aditi Jatkar
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Benjamin S Maciejewski
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Marina Amaro
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Harmeet Gandhok
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Mara Monetti
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Katherine Cialdea
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Eliza Bollinger
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - John M Kreeger
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Timothy M Coskran
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Alan C Opsahl
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Germaine G Boucher
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Morris J Birnbaum
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Paul DaSilva-Jardine
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Tim Rolph
- CVMET Research Unit (C.T.S., R.A.M., E.C., A.R., J.W., A.J., B.S.M., M.A., H.G., M.M., K.C., E.B., M.J.B., P.D.-J., T.R.), Worldwide Medicinal Chemistry (K.O.C., D.J.E.), and Pharmacokinetics, Dynamics, & Metabolism (A.S.K., D.A.T.), Pfizer Worldwide Research and Development, Cambridge, Massachusetts; and Worldwide Medicinal Chemistry (M.C., R.K., F.R., A.S., N.E.G.), and Drug Safety Research and Development (J.M.K., T.M.C., A.C.O., G.G.B.), Pfizer Worldwide Research and Development, Groton, Connecticut
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69
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Zschiedrich S, Bork T, Liang W, Wanner N, Eulenbruch K, Munder S, Hartleben B, Kretz O, Gerber S, Simons M, Viau A, Burtin M, Wei C, Reiser J, Herbach N, Rastaldi MP, Cohen CD, Tharaux PL, Terzi F, Walz G, Gödel M, Huber TB. Targeting mTOR Signaling Can Prevent the Progression of FSGS. J Am Soc Nephrol 2017; 28:2144-2157. [PMID: 28270414 DOI: 10.1681/asn.2016050519] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 01/16/2017] [Indexed: 01/04/2023] Open
Abstract
Mammalian target of rapamycin (mTOR) signaling is involved in a variety of kidney diseases. Clinical trials administering mTOR inhibitors to patients with FSGS, a prototypic podocyte disease, led to conflicting results, ranging from remission to deterioration of kidney function. Here, we combined complex genetic titration of mTOR complex 1 (mTORC1) levels in murine glomerular disease models, pharmacologic studies, and human studies to precisely delineate the role of mTOR in FSGS. mTORC1 target genes were significantly induced in microdissected glomeruli from both patients with FSGS and a murine FSGS model. Furthermore, a mouse model with constitutive mTORC1 activation closely recapitulated human FSGS. Notably, the complete knockout of mTORC1 by induced deletion of both Raptor alleles accelerated the progression of murine FSGS models. However, lowering mTORC1 signaling by deleting just one Raptor allele ameliorated the progression of glomerulosclerosis. Similarly, low-dose treatment with the mTORC1 inhibitor rapamycin efficiently diminished disease progression. Mechanistically, complete pharmacologic inhibition of mTOR in immortalized podocytes shifted the cellular energy metabolism toward reduced rates of oxidative phosphorylation and anaerobic glycolysis, which correlated with increased production of reactive oxygen species. Together, these data suggest that podocyte injury and loss is commonly followed by adaptive mTOR activation. Prolonged mTOR activation, however, results in a metabolic podocyte reprogramming leading to increased cellular stress and dedifferentiation, thus offering a treatment rationale for incomplete mTOR inhibition.
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Affiliation(s)
- Stefan Zschiedrich
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Tillmann Bork
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Wei Liang
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany.,Division of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Nicola Wanner
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Kristina Eulenbruch
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Stefan Munder
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Björn Hartleben
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Oliver Kretz
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, and
| | - Simon Gerber
- Imagine Institute, Institut national de la santé et de la recherche médicale (INSERM) U1163, Paris Descartes University-Sorbonne Paris Cité, Paris, France
| | - Matias Simons
- Imagine Institute, Institut national de la santé et de la recherche médicale (INSERM) U1163, Paris Descartes University-Sorbonne Paris Cité, Paris, France
| | - Amandine Viau
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Martine Burtin
- Institut national de la santé et de la recherche médicale (INSERM) U1151, Université Paris Descartes, Institut Necker Enfants Malades, Hopital Necker, Paris, France
| | - Changli Wei
- Department of Medicine, Rush University Medical Center, Chicago, IL
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL
| | - Nadja Herbach
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Munich, Germany
| | - Maria-Pia Rastaldi
- Renal Research Laboratory, Fondazione Istituto di ricovero e cura a carattere scientifico (IRCCS) Ospedale Maggiore Policlinico and Fondazione D'Amico, Milan, Italy
| | - Clemens D Cohen
- Division of Nephrology, Hypertension and Clinical Immunology, Städtisches Klinikum München, Munich, Germany
| | - Pierre-Louis Tharaux
- Paris Cardiovascular Research Centre (PARCC), Institut National de la Santé et de la Recherche Médicale, Paris, France; and
| | - Fabiola Terzi
- Institut national de la santé et de la recherche médicale (INSERM) U1151, Université Paris Descartes, Institut Necker Enfants Malades, Hopital Necker, Paris, France
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Markus Gödel
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany
| | - Tobias B Huber
- Department of Medicine IV, Faculty of Medicine, University of Freiburg, Germany; .,BIOSS Centre for Biological Signalling Studies, and.,Center for Systems Biology (ZBSA), Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Department of Medicine III, Faculty of Medicine University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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70
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Svegliati S, Amico D, Spadoni T, Fischetti C, Finke D, Moroncini G, Paolini C, Tonnini C, Grieco A, Rovinelli M, Funaro A, Gabrielli A. Agonistic Anti-PDGF Receptor Autoantibodies from Patients with Systemic Sclerosis Impact Human Pulmonary Artery Smooth Muscle Cells Function In Vitro. Front Immunol 2017; 8:75. [PMID: 28228756 PMCID: PMC5296309 DOI: 10.3389/fimmu.2017.00075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/17/2017] [Indexed: 01/12/2023] Open
Abstract
One of the earliest events in the pathogenesis of systemic sclerosis (SSc) is microvasculature damage with intimal hyperplasia and accumulation of cells expressing PDGF receptor. Stimulatory autoantibodies targeting PDGF receptor have been detected in SSc patients and demonstrated to induce fibrosis in vivo and convert in vitro normal fibroblasts into SSc-like cells. Since there is no evidence of the role of anti-PDGF receptor autoantibodies in the pathogenesis of SSc vascular lesions, we investigated the biologic effect of agonistic anti-PDGF receptor autoantibodies from SSc patients on human pulmonary artery smooth muscle cells and the signaling pathways involved. The synthetic (proliferation, migration, and type I collagen gene α1 chain expression) and contractile (smooth muscle-myosin heavy chain and smooth muscle-calponin expression) profiles of human pulmonary artery smooth muscle cells were assessed in vitro after incubation with SSc anti-PDGF receptors stimulatory autoantibodies. The role of reactive oxygen species, NOX isoforms, and mammalian target of rapamycin (mTOR) was investigated. Human pulmonary artery smooth muscle cells acquired a synthetic phenotype characterized by higher growth rate, migratory activity, gene expression of type I collagen α1 chain, and less expression of markers characteristic of the contractile phenotype such as smooth muscle-myosin heavy chain and smooth muscle-calponin when stimulated with PDGF and autoantibodies against PDGF receptor, but not with normal IgG. This phenotypic profile is mediated by increased generation of reactive oxygen species and expression of NOX4 and mTORC1. Our data indicate that agonistic anti-PDGF receptor autoantibodies may contribute to the pathogenesis of SSc intimal hyperplasia.
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Affiliation(s)
- Silvia Svegliati
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Donatella Amico
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Tatiana Spadoni
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Colomba Fischetti
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Doreen Finke
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Gianluca Moroncini
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Chiara Paolini
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Cecilia Tonnini
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Antonella Grieco
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Marina Rovinelli
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
| | - Ada Funaro
- Dipartimento di Scienze Mediche, Università di Torino, Torino, Italy
| | - Armando Gabrielli
- Clinica Medica, Dipartimento di Scienze Cliniche e Molecolari, Università Politecnica delle Marche , Ancona , Italy
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71
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Lesniewski LA, Seals DR, Walker AE, Henson GD, Blimline MW, Trott DW, Bosshardt GC, LaRocca TJ, Lawson BR, Zigler MC, Donato AJ. Dietary rapamycin supplementation reverses age-related vascular dysfunction and oxidative stress, while modulating nutrient-sensing, cell cycle, and senescence pathways. Aging Cell 2017; 16:17-26. [PMID: 27660040 PMCID: PMC5242306 DOI: 10.1111/acel.12524] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2016] [Indexed: 12/21/2022] Open
Abstract
Inhibition of mammalian target of rapamycin, mTOR, extends lifespan and reduces age-related disease. It is not known what role mTOR plays in the arterial aging phenotype or if mTOR inhibition by dietary rapamycin ameliorates age-related arterial dysfunction. To explore this, young (3.8 ± 0.6 months) and old (30.3 ± 0.2 months) male B6D2F1 mice were fed a rapamycin supplemented or control diet for 6-8 weeks. Although there were few other notable changes in animal characteristics after rapamycin treatment, we found that glucose tolerance improved in old mice, but was impaired in young mice, after rapamycin supplementation (both P < 0.05). Aging increased mTOR activation in arteries evidenced by elevated S6K phosphorylation (P < 0.01), and this was reversed after rapamycin treatment in old mice (P < 0.05). Aging was also associated with impaired endothelium-dependent dilation (EDD) in the carotid artery (P < 0.05). Rapamycin improved EDD in old mice (P < 0.05). Superoxide production and NADPH oxidase expression were higher in arteries from old compared to young mice (P < 0.05), and rapamycin normalized these (P < 0.05) to levels not different from young mice. Scavenging superoxide improved carotid artery EDD in untreated (P < 0.05), but not rapamycin-treated, old mice. While aging increased large artery stiffness evidenced by increased aortic pulse-wave velocity (PWV) (P < 0.01), rapamycin treatment reduced aortic PWV (P < 0.05) and collagen content (P < 0.05) in old mice. Aortic adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and expression of the cell cycle-related proteins PTEN and p27kip were increased with rapamycin treatment in old mice (all P < 0.05). Lastly, aging resulted in augmentation of the arterial senescence marker, p19 (P < 0.05), and this was ameliorated by rapamycin treatment (P < 0.05). These results demonstrate beneficial effects of rapamycin treatment on arterial function in old mice and suggest these improvements are associated with reduced oxidative stress, AMPK activation and increased expression of proteins involved in the control of the cell cycle.
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Affiliation(s)
- Lisa A. Lesniewski
- Division of GeriatricsDepartment of Internal MedicineSalt Lake CityUTUSA
- Veteran's Affairs Medical Center‐Salt Lake CityGeriatrics Research Education and Clinical CenterSalt Lake CityUTUSA
- Department of Exercise and Sports ScienceUniversity of UtahSalt Lake CityUTUSA
| | - Douglas R. Seals
- Department of Integrative PhysiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Ashley E. Walker
- Division of GeriatricsDepartment of Internal MedicineSalt Lake CityUTUSA
| | - Grant D. Henson
- Department of Exercise and Sports ScienceUniversity of UtahSalt Lake CityUTUSA
| | - Mark W. Blimline
- Department of Integrative PhysiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Daniel W. Trott
- Division of GeriatricsDepartment of Internal MedicineSalt Lake CityUTUSA
| | - Gary C. Bosshardt
- Division of GeriatricsDepartment of Internal MedicineSalt Lake CityUTUSA
| | - Thomas J. LaRocca
- Department of Integrative PhysiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Brooke R. Lawson
- Department of Integrative PhysiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Melanie C. Zigler
- Department of Integrative PhysiologyUniversity of Colorado BoulderBoulderCOUSA
| | - Anthony J. Donato
- Division of GeriatricsDepartment of Internal MedicineSalt Lake CityUTUSA
- Veteran's Affairs Medical Center‐Salt Lake CityGeriatrics Research Education and Clinical CenterSalt Lake CityUTUSA
- Department of Exercise and Sports ScienceUniversity of UtahSalt Lake CityUTUSA
- Department of BiochemistryUniversity of UtahSalt Lake CityUTUSA
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72
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Sweetwyne MT, Pippin JW, Eng DG, Hudkins KL, Chiao YA, Campbell MD, Marcinek DJ, Alpers CE, Szeto HH, Rabinovitch PS, Shankland SJ. The mitochondrial-targeted peptide, SS-31, improves glomerular architecture in mice of advanced age. Kidney Int 2017; 91:1126-1145. [PMID: 28063595 DOI: 10.1016/j.kint.2016.10.036] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 10/09/2016] [Accepted: 10/27/2016] [Indexed: 01/12/2023]
Abstract
Although age-associated changes in kidney glomerular architecture have been described in mice and man, the mechanisms are unknown. It is unclear if these changes can be prevented or even reversed by systemic therapies administered at advanced age. Using light microscopy and transmission electron microscopy, our results showed glomerulosclerosis with injury to mitochondria in glomerular epithelial cells in mice aged 26 months (equivalent to a 79-year-old human). To test the hypothesis that reducing mitochondrial damage in late age would result in lowered glomerulosclerosis, we administered the mitochondrial targeted peptide, SS-31, to aged mice. Baseline (24-month-old) mice were randomized to receive 8 weeks of SS-31, or saline, and killed at 26 months of age. SS-31 treatment improved age-related mitochondrial morphology and glomerulosclerosis. Assessment of glomeruli revealed that SS-31 reduced senescence (p16, senescence-associated-ß-Gal) and increased the density of parietal epithelial cells. However, SS-31 treatment reduced markers of parietal epithelial cell activation (Collagen IV, pERK1/2, and α-smooth muscle actin). SS-31 did not impact podocyte density, but it reduced markers of podocyte injury (desmin) and improved cytoskeletal integrity (synaptopodin). This was accompanied by higher glomerular endothelial cell density (CD31). Thus, despite initiating therapy in late-age mice, a short course of SS-31 has protective benefits on glomerular mitochondria, accompanied by temporal changes to the glomerular architecture. This systemic pharmacological intervention in old-aged animals limits glomerulosclerosis and senescence, reduces parietal epithelial cell activation, and improves podocyte and endothelial cell integrity.
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Affiliation(s)
| | - Jeffrey W Pippin
- Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Diana G Eng
- Division of Nephrology, University of Washington, Seattle, WA, USA
| | - Kelly L Hudkins
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Ying Ann Chiao
- Department of Pathology, University of Washington, Seattle, WA, USA
| | | | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, WA, USA
| | - Charles E Alpers
- Department of Pathology, University of Washington, Seattle, WA, USA
| | - Hazel H Szeto
- Department of Pharmacology, Weill Cornell Medical College, New York, NY, USA
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73
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NADPH oxidase 4 deficiency increases tubular cell death during acute ischemic reperfusion injury. Sci Rep 2016; 6:38598. [PMID: 27924932 PMCID: PMC5141508 DOI: 10.1038/srep38598] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 11/10/2016] [Indexed: 12/13/2022] Open
Abstract
NADPH oxidase 4 (NOX4) is highly expressed in kidney proximal tubular cells. NOX4 constitutively produces hydrogen peroxide, which may regulate important pro-survival pathways. Renal ischemia reperfusion injury (IRI) is a classical model mimicking human ischemic acute tubular necrosis. We hypothesized that NOX4 plays a protective role in kidney IRI. In wild type (WT) animals subjected to IRI, NOX4 protein expression increased after 24 hours. NOX4 KO (knock-out) and WT littermates mice were subjected to IRI. NOX4 KO mice displayed decreased renal function and more severe tubular apoptosis, decreased Bcl-2 expression and higher histologic damage scores compared to WT. Activation of NRF2 was decreased in NOX4 KO mice in response to IRI. This was related to decreased KEAP1 oxidation leading to decreased NRF2 stabilization. This resulted in decreased glutathione levels. In vitro silencing of NOX4 in cells showed an enhanced propensity to apoptosis, with reduced expression of NRF2, glutathione content and Bcl-2 expression, similar to cells derived from NOX4 KO mice. Overexpression of a constitutively active form of NRF2 (caNRF2) in NOX4 depleted cells rescued most of this phenotype in cultured cells, implying that NRF2 regulation by ROS issued from NOX4 may play an important role in its anti-apoptotic property.
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74
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Jonderian A, Maalouf R. Formulation and In vitro Interaction of Rhodamine-B Loaded PLGA Nanoparticles with Cardiac Myocytes. Front Pharmacol 2016; 7:458. [PMID: 27999542 PMCID: PMC5138196 DOI: 10.3389/fphar.2016.00458] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 11/14/2016] [Indexed: 01/29/2023] Open
Abstract
This study aims to characterize rhodamine B (Rh B) loaded poly(D,L-lactide-co-glycolide; PLGA) nanoparticles (NPs) and their interactions with cardiac myocytes. PLGA NPs were formulated using single emulsion solvent evaporation technique. The influence of varying parameters such as the stabilizer concentration, the sonication time, and the organic to aqueous ratio were investigated. The diameter, the dispersity, the encapsulation efficiency and the zeta potential of the optimized NPs were about 184 nm, 0.19, 40% and -21.7 mV, respectively. In vitro release showed that 29% of the Rh B was released within the first 8 h. Scanning electron microscopy measurements performed on the optimized NPs showed smooth surface and spherical shapes. No significant cytotoxic or apoptotic effects were observed on cardiac myocytes after 24 and 48 h of exposure with concentrations up to 200 μg/mL. The kinetic of the intracellular uptake was confirmed by confocal microscopy and cells took up PLGA NPs within the 1st hours. Interestingly, our data show an increase in the NPs' uptake with time of exposure. Taken together, we demonstrate for the first time that the designed NPs can be used as potential probes for drug delivery in cardiac myocytes.
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Affiliation(s)
| | - Rita Maalouf
- Department of Sciences, Notre Dame University – LouaizeZouk Mosbeh, Lebanon
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75
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Jin Y, Liu S, Ma Q, Xiao D, Chen L. Berberine enhances the AMPK activation and autophagy and mitigates high glucose-induced apoptosis of mouse podocytes. Eur J Pharmacol 2016; 794:106-114. [PMID: 27887947 DOI: 10.1016/j.ejphar.2016.11.037] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 11/19/2016] [Accepted: 11/21/2016] [Indexed: 12/15/2022]
Abstract
High glucose concentration can induce injury of podocytes and berberine has a potent activity against diabetic nephropathy. However, whether and how berberine can inhibit high glucose-mediated injury of podocytes have not been clarified. This study tested the effect of berberine on high glucose-mediated apoptosis and the AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) activation and autophagy in podocytes. The results indicated that berberine significantly mitigated high glucose-decreased cell viability, and nephrin and podocin expression as well as apoptosis in mouse podocytes. Berberine significantly increased the AMPK activation and mitigated high glucose and/or the AMPK inhibitor, compound C-mediated mTOR activation and apoptosis in podocytes. Berberine significantly enhanced the AMPK activation and protected from high glucose-induced apoptosis in the AMPK-silencing podocytes. Furthermore, berberine significantly increased the high glucose-elevated Unc-51-like autophagy-activating kinase 1 (ULK1) S317/S555 phosphorylation, Beclin-1 expression, the ratios of LC3II to LC3I expression and the numbers of autophagosomes, but reduced ULK1 S757 phosphorylation in podocytes. In addition, berberine significantly attenuated compound C-mediated inhibition of autophagy in podocytes. The protective effect of berberine on high glucose-induced podocyte apoptosis was significantly mitigated by pre-treatment with 3-methyladenine or bafilomycin A1. Collectively, berberine enhanced autophagy and protected from high glucose-induced injury in podocytes by promoting the AMPK activation. Our findings may provide new insights into the molecular mechanisms underlying the anti-diabetic nephropathy effect of berberine and may aid in design of new therapies for intervention of diabetic nephropathy.
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Affiliation(s)
- Yingli Jin
- Department of Pharmacology, College of Basic Medical Science, Jilin University, Xinmin Street 126, Changchun 130021, China
| | - Shuping Liu
- Department of Pharmacology, College of Basic Medical Science, Jilin University, Xinmin Street 126, Changchun 130021, China
| | - Qingshan Ma
- Department of Pediatrics, the First Bethune Hospital of Jilin University, Jilin University, Xinmin Street 71, Changchun 130021, China
| | - Dong Xiao
- Academy of Translational Medicine, the First Bethune Hospital of Jilin University, Jilin University, Xinmin Street 71, Changchun 130021, China
| | - Li Chen
- Department of Pharmacology, College of Basic Medical Science, Jilin University, Xinmin Street 126, Changchun 130021, China.
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76
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Eid S, Boutary S, Braych K, Sabra R, Massaad C, Hamdy A, Rashid A, Moodad S, Block K, Gorin Y, Abboud HE, Eid AA. mTORC2 Signaling Regulates Nox4-Induced Podocyte Depletion in Diabetes. Antioxid Redox Signal 2016; 25:703-719. [PMID: 27393154 PMCID: PMC5079418 DOI: 10.1089/ars.2015.6562] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIM Podocyte apoptosis is a critical mechanism for excessive loss of urinary albumin that eventuates in kidney fibrosis. Oxidative stress plays a critical role in hyperglycemia-induced glomerular injury. We explored the hypothesis that mammalian target of rapamycin complex 2 (mTORC2) mediates podocyte injury in diabetes. RESULTS High glucose (HG)-induced podocyte injury reflected by alterations in the slit diaphragm protein podocin and podocyte depletion/apoptosis. This was paralleled by activation of the Rictor/mTORC2/Akt pathway. HG also increased the levels of Nox4 and NADPH oxidase activity. Inhibition of mTORC2 using small interfering RNA (siRNA)-targeting Rictor in vitro decreased HG-induced Nox1 and Nox4, NADPH oxidase activity, restored podocin levels, and reduced podocyte depletion/apoptosis. Inhibition of mTORC2 had no effect on mammalian target of rapamycin complex 1 (mTORC1) activation, described by our group to be increased in diabetes, suggesting that the mTORC2 activation by HG could mediate podocyte injury independently of mTORC1. In isolated glomeruli of OVE26 mice, there was a similar activation of the Rictor/mTORC2/Akt signaling pathway with increase in Nox4 and NADPH oxidase activity. Inhibition of mTORC2 using antisense oligonucleotides targeting Rictor restored podocin levels, reduced podocyte depletion/apoptosis, and attenuated glomerular injury and albuminuria. INNOVATION Our data provide evidence for a novel function of mTORC2 in NADPH oxidase-derived reactive oxygen species generation and podocyte apoptosis that contributes to urinary albumin excretion in type 1 diabetes. CONCLUSION mTORC2 and/or NADPH oxidase inhibition may represent a therapeutic modality for diabetic kidney disease. Antioxid. Redox Signal. 25, 703-719.
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Affiliation(s)
- Stéphanie Eid
- 1 Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon .,2 UMR-S 1124 INSERM, Paris Descartes University, Sorbonne Paris Cite University , Centre Interdisciplinaire Chimie Biology, Paris, France
| | - Suzan Boutary
- 1 Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon
| | - Kawthar Braych
- 1 Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon
| | - Ramzi Sabra
- 3 Department of Pharmacology and Toxicology, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon
| | - Charbel Massaad
- 2 UMR-S 1124 INSERM, Paris Descartes University, Sorbonne Paris Cite University , Centre Interdisciplinaire Chimie Biology, Paris, France
| | - Ahmed Hamdy
- 4 Department of Nephrology, Hamad Medical Corporation , Doha, Qatar
| | - Awad Rashid
- 4 Department of Nephrology, Hamad Medical Corporation , Doha, Qatar
| | - Sarah Moodad
- 1 Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon
| | - Karen Block
- 5 Department of Medicine, South Texas Veterans Healthcare System and the University of Texas Health Science Center , San Antonio, Texas
| | - Yves Gorin
- 5 Department of Medicine, South Texas Veterans Healthcare System and the University of Texas Health Science Center , San Antonio, Texas
| | - Hanna E Abboud
- 5 Department of Medicine, South Texas Veterans Healthcare System and the University of Texas Health Science Center , San Antonio, Texas
| | - Assaad A Eid
- 1 Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut , Beirut, Lebanon
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He T, Xiong J, Nie L, Yu Y, Guan X, Xu X, Xiao T, Yang K, Liu L, Zhang D, Huang Y, Zhang J, Wang J, Sharma K, Zhao J. Resveratrol inhibits renal interstitial fibrosis in diabetic nephropathy by regulating AMPK/NOX4/ROS pathway. J Mol Med (Berl) 2016; 94:1359-1371. [PMID: 27488452 DOI: 10.1007/s00109-016-1451-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 07/01/2016] [Accepted: 07/24/2016] [Indexed: 02/07/2023]
Abstract
Renal interstitial fibrosis is a major pathologic feature of diabetic nephropathy, while the pathogenesis and therapeutic interventions of diabetic renal interstitial fibrosis are not well established. In this study, we first demonstrated that high glucose could induce renal fibroblast (NRK-49F) cell proliferation and activation to myofibroblasts, accompanied by a significant increase in the intracellular levels of reactive oxygen species (ROS) derived from nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). ROS-mediated ERK1/2 activation was found to play a crucial role in high glucose-induced fibroblast proliferation and activation. Resveratrol, like the NOX4-targeting small interfering RNA (siRNA), markedly inhibited high glucose-induced fibroblast proliferation and activation by reducing NOX4-derived ROS production. It was then revealed that the increase in the expression of NOX4 induced by high glucose was due to the inactivation of AMP-activated protein kinase (AMPK), which could be reversed by resveratrol. Further in vivo investigation demonstrated that resveratrol treatment significantly attenuated renal fibrosis in db/db mice, accompanied by an evident increase in phospho-AMPK and decrease in NOX4. In summary, our results suggest that high glucose can directly promote renal fibroblasts proliferation and activation in a ROS-dependent manner, and resveratrol is a potential therapeutic agent against diabetic renal fibrosis via regulation of AMPK/NOX4/ROS signaling. KEY MESSAGE Resveratrol inhibits high glucose-induced NRK cell activation by decreasing NOX4-derived ROS. Resveratrol inhibits high glucose-induced NOX4 expression in NRK cells via activation of AMPK. ROS-activated ERK1/2 signaling is involved in high glucose-induced NRK cell activation. Resveratrol attenuated renal fibrosis in db/db mice via regulation of AMPK/NOX4/ROS signaling.
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Affiliation(s)
- Ting He
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Jiachuan Xiong
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Ling Nie
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Yanlin Yu
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Xu Guan
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Xinli Xu
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Tangli Xiao
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Ke Yang
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Liang Liu
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Daohai Zhang
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Yunjian Huang
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Jingbo Zhang
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China
| | - Junping Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Third Military Medical University, Chongqing, 400038, People's Republic of China
| | - Kumar Sharma
- Center for Renal Translational Medicine, Division of Nephrology-Hypertension, University of California, La Jolla, CA, USA.,Veterans Administration San Diego HealthCare System, La Jolla, CA, USA
| | - Jinghong Zhao
- Department of Nephrology, Institute of Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, People's Republic of China.
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78
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Roles of mTOR complexes in the kidney: implications for renal disease and transplantation. Nat Rev Nephrol 2016; 12:587-609. [PMID: 27477490 DOI: 10.1038/nrneph.2016.108] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.
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79
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"Inflammaging" as a Druggable Target: A Senescence-Associated Secretory Phenotype-Centered View of Type 2 Diabetes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1810327. [PMID: 27340505 PMCID: PMC4908264 DOI: 10.1155/2016/1810327] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/09/2016] [Indexed: 12/22/2022]
Abstract
Aging is a complex phenomenon driven by a variety of molecular alterations. A relevant feature of aging is chronic low-grade inflammation, termed “inflammaging.” In type 2 diabetes mellitus (T2DM), many elements of aging appear earlier or are overrepresented, including consistent inflammaging. T2DM patients have an increased death rate, associated with an incremented inflammatory score. The source of this inflammation is debated. Recently, the senescence-associated secretory phenotype (SASP) has been proposed as the main origin of inflammaging in both aging and T2DM. Different pathogenic mechanisms linked to T2DM progression and complications development have been linked to senescence and SASP, that is, oxidative stress and endoplasmic reticulum (ER) stress. Here we review the latest data connecting oxidative and ER stress with the SASP in the context of aging and T2DM, with emphasis on endothelial cells (ECs) and endothelial dysfunction. Moreover, since current medical practice is insufficient to completely suppress the increased death rate of diabetic patients, we propose a SASP-centered view of T2DM as a futuristic therapeutic option, possibly opening new prospects by moving the attention from one-organ studies of diabetes complications to a wider targeting of the aging process.
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80
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Abstract
Diabetes is increasing in prevalence and is the leading cause of end-stage renal disease in the United States. Diabetic kidney disease is considered a proteinuric glomerular disease. Although the glomerulus is composed of various cell types, research suggests that podocytes are critical to overall glomerular health. Podocyte injury has been identified as a pivotal event resulting in proteinuric kidney disease, glomerulosclerosis, and loss of renal function. Thus, understanding the signaling mechanisms that trigger podocyte injury in diabetic kidney disease might allow for the development of targeted therapeutics to prevent or ameliorate progression to end-stage renal failure. This review focuses on the role of podocytes in diabetic kidney disease.
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Affiliation(s)
- Jamie S Lin
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Katalin Susztak
- Renal-Electrolyte and Hypertension Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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81
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Nayak BK, Shanmugasundaram K, Friedrichs WE, Cavaglierii RC, Patel M, Barnes J, Block K. HIF-1 Mediates Renal Fibrosis in OVE26 Type 1 Diabetic Mice. Diabetes 2016; 65:1387-97. [PMID: 26908870 PMCID: PMC4839204 DOI: 10.2337/db15-0519] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 01/19/2016] [Indexed: 12/19/2022]
Abstract
Hypoxia-inducible factor (HIF)-1 mediates hypoxia- and chronic kidney disease-induced fibrotic events. Here, we assessed whether HIF-1 blockade attenuates the manifestations of diabetic nephropathy in a type 1 diabetic animal model, OVE26. YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole], an HIF-1 inhibitor, reduced whole kidney glomerular hypertrophy, mesangial matrix expansion, extracellular matrix accumulation, and urinary albumin excretion as well as NOX4 protein expression and NADPH-dependent reactive oxygen species production, while blood glucose levels remained unchanged. The role of NOX oxidases in HIF-1-mediated extracellular matrix accumulation was explored in vitro using glomerular mesangial cells. Through a series of genetic silencing and adenoviral overexpression studies, we have defined GLUT1 as a critical downstream target of HIF-1α mediating high glucose-induced matrix expression through the NADPH oxidase isoform, NOX4. Together, our data suggest that pharmacological inhibition of HIF-1 may improve clinical manifestations of diabetic nephropathy.
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Affiliation(s)
- Bijaya K Nayak
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | | | - William E Friedrichs
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Rita C Cavaglierii
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Mandakini Patel
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Jeffrey Barnes
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX Audie L. Murphy Memorial VA Hospital Division, South Texas Veterans Health Care System, San Antonio, TX
| | - Karen Block
- Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX Audie L. Murphy Memorial VA Hospital Division, South Texas Veterans Health Care System, San Antonio, TX
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82
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Yao Y, Wang J, Yoshida S, Nada S, Okada M, Inoki K. Role of Ragulator in the Regulation of Mechanistic Target of Rapamycin Signaling in Podocytes and Glomerular Function. J Am Soc Nephrol 2016; 27:3653-3665. [PMID: 27032892 DOI: 10.1681/asn.2015010032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 02/17/2016] [Indexed: 02/03/2023] Open
Abstract
Aberrant activation of mechanistic target of rapamycin complex 1 (mTORC1) in glomerular podocytes leads to glomerular insufficiency and may contribute to the development of glomerular diseases, including diabetic nephropathy. Thus, an approach for preventing mTORC1 activation may allow circumvention of the onset and progression of mTORC1-dependent podocyte injury and glomerular diseases. mTORC1 activation requires inputs from both growth factors and nutrients that inactivate the tuberous sclerosis complex (TSC), a key suppressor of mTORC1, on the lysosome. Previous studies in mice revealed that the growth factor-phosphatidylinositol 3-kinase pathway and mTORC1 are essential for maintaining normal podocyte function, suggesting that direct inhibition of the phosphatidylinositol 3-kinase pathway or mTORC1 may not be an ideal approach to sustaining physiologic podocyte functions under certain disease conditions. Here, we report the role of the Ragulator complex, which recruits mTORC1 to lysosomes in response to nutrient availability in podocytes. Notably, podocytes lacking Ragulator maintain basal mTORC1 activity. Unlike podocyte-specific mTORC1-knockout mice, mice lacking functional Ragulator in podocytes did not show abnormalities in podocyte or glomerular function. However, aberrant mTORC1 activation induced by active Rheb in podocyte-specific TSC1-knockout (podo-TSC1 KO) mice did require Ragulator. Moreover, ablation of Ragulator in the podocytes of podo-TSC1 KO mice or streptozotocin-induced diabetic mice significantly blocked the development of pathologic renal phenotypes. These observations suggest that the blockade of mTORC1 recruitment to lysosomes may be a useful clinical approach to attenuate aberrant mTORC1 activation under certain disease conditions.
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Affiliation(s)
| | | | - Sei Yoshida
- Life Sciences Institute.,Department of Microbiology and Immunology
| | - Shigeyuki Nada
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Masato Okada
- Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Ken Inoki
- Life Sciences Institute, .,Department of Molecular and Integrative Physiology, and.,Department of Internal Medicine, Division of Nephrology, University of Michigan, Ann Arbor, Michigan; and
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83
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Langer S, Kreutz R, Eisenreich A. Metformin modulates apoptosis and cell signaling of human podocytes under high glucose conditions. J Nephrol 2016; 29:765-773. [PMID: 26733332 DOI: 10.1007/s40620-015-0258-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 12/15/2015] [Indexed: 12/22/2022]
Abstract
Diabetic nephropathy, which is associated with loss of human (h) podocytes (PC), is a major complication in diabetes mellitus. High-glucose modulates AMP-activated protein kinase (AMPK) signaling and cell apoptosis. Metformin has been demonstrated to reduce apoptosis and albuminuria in type 2 diabetes. Here, we examined the effect of metformin on cell apoptosis and on pro-/anti-apoptotic signaling in hPC. Expression analyses were done by real-time polymerase chain reaction and western blotting. Moreover, a functional apoptosis assay was performed in hPC. Determination of kinase activation by phosphorylation was done via immunodetection analyses and digital quantification. We found that hPC express organic cation transporter 1 which is the major uptake transporter of metformin. High-glucose reduced AMPK phosphorylation and induced mammalian target of rapamycin (mTOR) activation in podocytes, which was abolished and reversed by pre-treatment with metformin. Furthermore, metformin reduced high-glucose-induced podocytes apoptosis in a concentration-dependent manner. In summary, metformin exhibits an anti-apoptotic impact on podocytes under high-glucose conditions via activation of AMPK and inhibition of mTOR signaling. These data support a beneficial effect of metformin in diabetic nephropathy.
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Affiliation(s)
- Sebastian Langer
- Klinische Pharmakologie und Toxikologie, CC04, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Reinhold Kreutz
- Klinische Pharmakologie und Toxikologie, CC04, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Andreas Eisenreich
- Klinische Pharmakologie und Toxikologie, CC04, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
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84
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Gong Q, Hou F. Silencing of angiotensin II type-1 receptor inhibits high glucose-induced epithelial–mesenchymal transition in human renal proximal tubular epithelial cells via inactivation of mTOR/p70S6K signaling pathway. Biochem Biophys Res Commun 2016; 469:183-8. [DOI: 10.1016/j.bbrc.2015.11.092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/20/2015] [Indexed: 12/18/2022]
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85
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Bhatti AB, Usman M. Drug Targets for Oxidative Podocyte Injury in Diabetic Nephropathy. Cureus 2015; 7:e393. [PMID: 26798569 PMCID: PMC4699926 DOI: 10.7759/cureus.393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 11/30/2015] [Indexed: 12/19/2022] Open
Abstract
Diabetic nephropathy (DN) is one the most prevalent chronic complications of diabetes mellitus that affects as much as one-third of diabetic patients irrespective of the type of diabetes. Hyperglycemia is the key trigger for DN that initiates a number of microscopic and ultramicroscopic changes in kidney architecture. Microscopic changes include thickening of the glomerular basement membrane (GBM), tubular basement membrane (TBM), mesangial proliferation, arteriosclerosis, and glomerulotubular junction abnormalities (GTJA). Among the ultramicroscopic changes, effacement of podocytes and decrease in their density seem to be the centerpiece of DN pathogenesis. These changes in kidney architecture then produce functional deficits, such as microalbuminuria and decreased glomerular filtration rate (GFR). Among several mechanisms involved in inflicting damage to podocytes, injuries sustained by increased oxidative stress turns out to be the most important mechanism. Different variables that are included in increased production of reactive oxygen species (ROS) include a hyperglycemia-induced reduction in glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation via hyperglycemia, advanced glycation end products (AGEs), protein kinase C (PKC), and renin-angiotensin-aldosterone system (RAAS). Unfortunately, control of podocyte injury hasn't received much attention as a treatment approach for DN. Therefore, this review article is mainly concerned with the exploration of various treatment options that might help in decreasing the podocyte injury, mainly by reducing the level of NADPH oxidase-mediated generation of ROS. This article concludes with a view that certain NADPH oxidase inhibitors, RAAS inhibitors, statins, antidiabetic drugs, and antioxidant vitamins might be useful in decreasing podocyte injury and resultant structural and functional kidney impairments in DN.
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Affiliation(s)
- Adnan Bashir Bhatti
- Department of Medicine, Capital Development Authority Hospital, Islamabad, Pakistan
| | - Muhammad Usman
- Department of Medicine, Jinnah Hospital Lahore (JHL)/Allama Iqbal Medical College (AIMC), Lahore, Pakistan
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86
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Das R, Xu S, Nguyen TT, Quan X, Choi SK, Kim SJ, Lee EY, Cha SK, Park KS. Transforming Growth Factor β1-induced Apoptosis in Podocytes via the Extracellular Signal-regulated Kinase-Mammalian Target of Rapamycin Complex 1-NADPH Oxidase 4 Axis. J Biol Chem 2015; 290:30830-42. [PMID: 26565025 DOI: 10.1074/jbc.m115.703116] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Indexed: 02/04/2023] Open
Abstract
TGF-β is a pleiotropic cytokine that accumulates during kidney injuries, resulting in various renal diseases. We have reported previously that TGF-β1 induces the selective up-regulation of mitochondrial Nox4, playing critical roles in podocyte apoptosis. Here we investigated the regulatory mechanism of Nox4 up-regulation by mTORC1 activation on TGF-β1-induced apoptosis in immortalized podocytes. TGF-β1 treatment markedly increased the phosphorylation of mammalian target of rapamycin (mTOR) and its downstream targets p70S6K and 4EBP1. Blocking TGF-β receptor I with SB431542 completely blunted the phosphorylation of mTOR, p70S6K, and 4EBP1. Transient adenoviral overexpression of mTOR-WT and constitutively active mTORΔ augmented TGF-β1-treated Nox4 expression, reactive oxygen species (ROS) generation, and apoptosis, whereas mTOR kinase-dead suppressed the above changes. In addition, knockdown of mTOR mimicked the effect of mTOR-KD. Inhibition of mTORC1 by low-dose rapamycin or knockdown of p70S6K protected podocytes through attenuation of Nox4 expression and subsequent oxidative stress-induced apoptosis by TGF-β1. Pharmacological inhibition of the MEK-ERK cascade, but not the PI3K-Akt-TSC2 pathway, abolished TGF-β1-induced mTOR activation. Inhibition of either ERK1/2 or mTORC1 did not reduce the TGF-β1-stimulated increase in Nox4 mRNA level but significantly inhibited total Nox4 expression, ROS generation, and apoptosis induced by TGF-β1. Moreover, double knockdown of Smad2 and 3 or only Smad4 completely suppressed TGF-β1-induced ERK1/2-mTORactivation. Our data suggest that TGF-β1 increases translation of Nox4 through the Smad-ERK1/2-mTORC1 axis, which is independent of transcriptional regulation. Activation of this pathway plays a crucial role in ROS generation and mitochondrial dysfunction, leading to podocyte apoptosis. Therefore, inhibition of the ERK1/2-mTORC1 pathway could be a potential therapeutic and preventive target in proteinuric and chronic kidney diseases.
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Affiliation(s)
- Ranjan Das
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Shanhua Xu
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Tuyet Thi Nguyen
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Xianglan Quan
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Seong-Kyung Choi
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Soo-Jin Kim
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Eun Young Lee
- the Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan 330-721, Republic of Korea
| | - Seung-Kuy Cha
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
| | - Kyu-Sang Park
- From the Department of Physiology, Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Republic of Korea and
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87
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Okamura DM, Pennathur S. The balance of powers: Redox regulation of fibrogenic pathways in kidney injury. Redox Biol 2015; 6:495-504. [PMID: 26448394 PMCID: PMC4600846 DOI: 10.1016/j.redox.2015.09.039] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/22/2015] [Accepted: 09/22/2015] [Indexed: 01/13/2023] Open
Abstract
Oxidative stress plays a central role in the pathogenesis of diverse chronic inflammatory disorders including diabetic complications, cardiovascular disease, aging, and chronic kidney disease (CKD). Patients with moderate to advanced CKD have markedly increased levels of oxidative stress and inflammation that likely contribute to the unacceptable high rates of morbidity and mortality in this patient population. Oxidative stress is defined as an imbalance of the generation of reactive oxygen species (ROS) in excess of the capacity of cells/tissues to detoxify or scavenge them. Such a state of oxidative stress may alter the structure/function of cellular macromolecules and tissues that eventually leads to organ dysfunction. The harmful effects of ROS have been largely attributed to its indiscriminate, stochastic effects on the oxidation of protein, lipids, or DNA but in many instances the oxidants target particular amino acid residues or lipid moieties. Oxidant mechanisms are intimately involved in cell signaling and are linked to several key redox-sensitive signaling pathways in fibrogenesis. Dysregulation of antioxidant mechanisms and overproduction of ROS not only promotes a fibrotic milieu but leads to mitochondrial dysfunction and further exacerbates kidney injury. Our studies support the hypothesis that unique reactive intermediates generated in localized microenvironments of vulnerable tissues such as the kidney activate fibrogenic pathways and promote end-organ damage. The ability to quantify these changes and assess response to therapies will be pivotal in understanding disease mechanisms and monitoring efficacy of therapy.
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Affiliation(s)
- Daryl M Okamura
- Seattle Children's Research Institute, Department of Pediatrics, University of Washington, Seattle, WA, USA.
| | - Subramaniam Pennathur
- University of Michigan, Department of Medicine, Division of Nephrology, Ann Arbor, MI, USA
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88
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Zhang J, Hu X, Wang S, Zhang Y, Yang H. Protective effects of low-dose rapamycin combined with valsartan on podocytes of diabetic rats. Int J Clin Exp Med 2015; 8:13275-13281. [PMID: 26550253 PMCID: PMC4612938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/04/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to study the impacts and the mechanisms of low-dose rapamycin combined with valsartan on the renal functions of diabetic nephropathy (DN) rats. 50 SD rats were randomly divided into the normal control group (group A, n=10) and the DN model group (n=40), the DN model group was intraperitoneally injected streptozocin (STZ) for the modeling, which were then equally divided into the DN group (group B), the rapamycin group (group C, orally administrated rapamycin 1 mg/kg/d), the valsartan group (group D, orally administrated valsartan 30 mg/kg/d) and the combined therapy group (group E, orally administrated rapamycin 1 mg/kg/d + valsartan 30 mg/kg/d). Group A and group B were orally administrated the same amount of 0.5% carboxymethylcellulose. After 8-week treatment, the rats of each group were killed for the renal functional and pathological detection, as well as the expression detection of nephrin and podocin of kidney tissues. Compared with group A, the renal functions of the DN model groups were all decreased, and the pathological changes were significant. Meanwhile, the expressions of nephrin/podocin were reduced (P<0.05); among which group B exhibited the most serious changes, while the situations of group E were improved after the combined treatment, the expressions of nephrin/podocin were increased. Low-dose rapamycin and valsartan could enhance the expressions of nephrin and podocin, reduce kidney damages, thus achieving the protective effects towards the kidneys, and the effects of the combined therapy were superior to those of monotherapy.
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Affiliation(s)
- Jin Zhang
- Department of Nephrology, The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou 450052, Henan, China
| | - Xiaozhou Hu
- Department of Nephrology, The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou 450052, Henan, China
| | - Shaoting Wang
- Department of Nephrology, The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou 450052, Henan, China
| | - Yan Zhang
- Department of Nephrology, The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou 450052, Henan, China
| | - Hong Yang
- Department of Nephrology, The Fifth Affiliated Hospital of Zhengzhou University Zhengzhou 450052, Henan, China
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Abstract
PURPOSE OF REVIEW Nox-4 is a member of the NADPH oxidase (Nox) family of enzymes implicated in reactive oxygen species generation. Nox-4 is distributed in many tissues; however, its physiological functions remain poorly understood. In contrast to other Nox isoforms, it is unique in that it produces large amounts of hydrogen peroxide constitutively and does not require other cytosolic oxidase components for its activation. This review highlights the recent developments in Nox-4 research and progressive kidney disease as well as the potential of new Nox-4 inhibitors to reduce renal damage. RECENT FINDINGS Recently, Nox-4 was shown to be implicated in kidney diseases such as diabetic nephropathy. Nox-4 has been identified as playing a role in damage to the kidney induced by hyperglycaemia and other major pathways of renal damage, including advanced glycation end-products, the renin-angiotensin system, TGF-β and protein kinase C. SUMMARY The role of Nox-4 as a target for renoprotection remains controversial, although recent positive preclinical data have stimulated increased interest in inhibiting the enzyme in clinical trials of renal disease.
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90
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Dey N, Bera A, Das F, Ghosh-Choudhury N, Kasinath BS, Choudhury GG. High glucose enhances microRNA-26a to activate mTORC1 for mesangial cell hypertrophy and matrix protein expression. Cell Signal 2015; 27:1276-85. [PMID: 25797045 PMCID: PMC4437875 DOI: 10.1016/j.cellsig.2015.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/06/2015] [Accepted: 03/15/2015] [Indexed: 02/06/2023]
Abstract
High glucose milieu inhibits PTEN expression to activate Akt kinase and induces glomerular mesangial cell hypertrophy and matrix protein expression in diabetic nephropathy. Specific mechanism by which high glucose inhibits PTEN expression is not clear. We found that high glucose increased the expression of the microRNA-26a (miR-26a) in mesangial cells. Using a sensor plasmid with 3'UTR-driven luciferase, we showed PTEN as a target of miR-26a in response to high glucose. Overexpression of miR-26a reduced the PTEN protein levels resulting in increased Akt kinase activity similar to high glucose treatment. In contrast, anti-miR-26a reversed high glucose-induced suppression of PTEN with concomitant inhibition of Akt kinase activity. Akt-mediated phosphorylation of tuberin and PRAS40 regulates mTORC1, which is necessary for mesangial cell hypertrophy and matrix protein expression. Inhibition of high glucose-induced miR-26a blocked phosphorylation of tuberin and PRAS40, which lead to suppression of phosphorylation of S6 kinase and 4EBP-1, two substrates of mTORC1. Furthermore, we show that expression of miR-26a induced mesangial cell hypertrophy and increased fibronectin and collagen I (α2) expression similar to that observed with the cells incubated with high glucose. Anti-miR-26a inhibited these phenomena in response to high glucose. Together our results provide the first evidence for the involvement of miR-26a in high glucose-induced mesangial cell hypertrophy and matrix protein expression. These data indicate the potential therapeutic utility of anti-miR-26a for the complications of diabetic kidney disease.
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Affiliation(s)
- Nirmalya Dey
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Amit Bera
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Falguni Das
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Nandini Ghosh-Choudhury
- VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, University of Texas Health Science Center at San Antonio, Texas, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States; VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States; VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, United States.
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91
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Gorin Y, Wauquier F. Upstream regulators and downstream effectors of NADPH oxidases as novel therapeutic targets for diabetic kidney disease. Mol Cells 2015; 38:285-96. [PMID: 25824546 PMCID: PMC4400302 DOI: 10.14348/molcells.2015.0010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress has been linked to the pathogenesis of diabetic nephropathy, the complication of diabetes in the kidney. NADPH oxidases of the Nox family, and in particular the homologue Nox4, are a major source of reactive oxygen species in the diabetic kidney and are critical mediators of redox signaling in glomerular and tubulointerstitial cells exposed to the diabetic milieu. Here, we present an overview of the current knowledge related to the understanding of the role of Nox enzymes in the processes that control mesangial cell, podocyte and tubulointerstitial cell injury induced by hyperglycemia and other predominant factors enhanced in the diabetic milieu, including the renin-angiotensin system and transforming growth factor-β. The nature of the upstream modulators of Nox enzymes as well as the downstream targets of the Nox NADPH oxidases implicated in the propagation of the redox processes that alter renal biology in diabetes will be highlighted.
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Affiliation(s)
- Yves Gorin
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas,
USA
| | - Fabien Wauquier
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas,
USA
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92
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Axelsson J, Rippe A, Rippe B. mTOR inhibition with temsirolimus causes acute increases in glomerular permeability, but inhibits the dynamic permeability actions of puromycin aminonucleoside. Am J Physiol Renal Physiol 2015; 308:F1056-64. [PMID: 25740597 DOI: 10.1152/ajprenal.00632.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/25/2015] [Indexed: 01/21/2023] Open
Abstract
Inhibitors of the mammalian target of rapamycin (mTORi) can produce de novo proteinuria in kidney transplant patients. On the other hand, mTORi has been shown to suppress disease progression in several animal models of kidney disease. In the present study, we investigated whether glomerular permeability can be acutely altered by the mTORi temsirolimus and whether mTORi can affect acute puromycin aminonucleoside (PAN) or angiotensin II (ANG II)-induced glomerular hyperpermeability. In anesthetized Wistar rats, the left ureter was cannulated for urine collection, while simultaneously blood access was achieved. Temsirolimus was administered as a single intravenous dose 30 min before the start of the experiments in animals infused with PAN or ANG II or in nonexposed animals. Polydispersed FITC-Ficoll-70/400 (molecular radius 10-80 Å) and (51)Cr-EDTA infusion was given during the whole experiment. Measurements of Ficoll in plasma and urine were performed sequentially before the temsirolimus injection (baseline) and at 5, 15, 30, 60, and 120 min after the start of the experiments. Urine and plasma samples were analyzed by high-performance size-exclusion chromatography (HPSEC) to assess glomerular sieving coefficients (θ) for Ficoll10-80Å. Temsirolimus per se increased baseline glomerular permeability to Ficoll50-80Å 45 min after its administration, a reactive oxygen species (ROS)-dependent phenomenon. PAN caused a rapid and reversible increase in glomerular permeability, peaking at 5 min, and again at 60-120 min, which could be blocked by the ROS scavenger tempol. mTORi abrogated the second permeability peak induced by PAN. However, it had no effect on the immediate ANG II- or PAN-induced increases in glomerular permeability.
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Affiliation(s)
| | - Anna Rippe
- Department of Nephrology, Lund University, Lund, Sweden
| | - Bengt Rippe
- Department of Nephrology, Lund University, Lund, Sweden
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93
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Abstract
The concept that excess superoxide production from mitochondria is the driving, initial cellular response underlying diabetes complications has been held for the past decade. However, results of antioxidant-based trials have been largely negative. In the present review, the data supporting mitochondrial superoxide as a driving force for diabetic kidney, nerve, heart, and retinal complications are reexamined, and a new concept for diabetes complications--mitochondrial hormesis--is presented. In this view, production of mitochondrial superoxide can be an indicator of healthy mitochondria and physiologic oxidative phosphorylation. Recent data suggest that in response to excess glucose exposure or nutrient stress, there is a reduction of mitochondrial superoxide, oxidative phosphorylation, and mitochondrial ATP generation in several target tissues of diabetes complications. Persistent reduction of mitochondrial oxidative phosphorylation complex activity is associated with the release of oxidants from nonmitochondrial sources and release of proinflammatory and profibrotic cytokines, and a manifestation of organ dysfunction. Restoration of mitochondrial function and superoxide production via activation of AMPK has now been associated with improvement in markers of renal, cardiovascular, and neuronal dysfunction with diabetes. With this Perspective, approaches that stimulate AMPK and PGC1α via exercise, caloric restriction, and medications result in stimulation of mitochondrial oxidative phosphorylation activity, restore physiologic mitochondrial superoxide production, and promote organ healing.
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Affiliation(s)
- Kumar Sharma
- Center for Renal Translational Medicine, Division of Nephrology-Hypertension, Department of Medicine, University of California, San Diego, San Diego, CA, and Division of Nephrology-Hypertension, Veterans Affairs San Diego Healthcare System, Veterans Medical Research Foundation, San Diego, CA
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94
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Gorin Y, Cavaglieri RC, Khazim K, Lee DY, Bruno F, Thakur S, Fanti P, Szyndralewiez C, Barnes JL, Block K, Abboud HE. Targeting NADPH oxidase with a novel dual Nox1/Nox4 inhibitor attenuates renal pathology in type 1 diabetes. Am J Physiol Renal Physiol 2015; 308:F1276-87. [PMID: 25656366 DOI: 10.1152/ajprenal.00396.2014] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 02/03/2015] [Indexed: 01/04/2023] Open
Abstract
Reactive oxygen species (ROS) generated by Nox NADPH oxidases may play a critical role in the pathogenesis of diabetic nephropathy (DN). The efficacy of the Nox1/Nox4 inhibitor GKT137831 on the manifestations of DN was studied in OVE26 mice, a model of type 1 diabetes. Starting at 4-5 mo of age, OVE26 mice were treated with GKT137831 at 10 or 40 mg/kg, once-a-day for 4 wk. At both doses, GKT137831 inhibited NADPH oxidase activity, superoxide generation, and hydrogen peroxide production in the renal cortex from diabetic mice without affecting Nox1 or Nox4 protein expression. The increased expression of fibronectin and type IV collagen was reduced in the renal cortex, including glomeruli, of diabetic mice treated with GKT137831. GKT137831 significantly reduced glomerular hypertrophy, mesangial matrix expansion, urinary albumin excretion, and podocyte loss in OVE26 mice. GKT137831 also attenuated macrophage infiltration in glomeruli and tubulointerstitium. Collectively, our data indicate that pharmacological inhibition of Nox1/4 affords broad renoprotection in mice with preexisting diabetes and established kidney disease. This study validates the relevance of targeting Nox4 and identifies GKT137831 as a promising compound for the treatment of DN in type 1 diabetes.
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Affiliation(s)
- Yves Gorin
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas;
| | - Rita C Cavaglieri
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Khaled Khazim
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Doug-Yoon Lee
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Francesca Bruno
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Sachin Thakur
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Paolo Fanti
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas; Audie Leon Murphy Memorial Hospital Division, South Texas Veterans Health Care System, San Antonio, Texas; and
| | | | - Jeffrey L Barnes
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas; Audie Leon Murphy Memorial Hospital Division, South Texas Veterans Health Care System, San Antonio, Texas; and
| | - Karen Block
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas; Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas
| | - Hanna E Abboud
- Department of Medicine, The University of Texas Health Science Center, San Antonio, Texas; Audie Leon Murphy Memorial Hospital Division, South Texas Veterans Health Care System, San Antonio, Texas; and
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95
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Wang H, Chen X, Su Y, Paueksakon P, Hu W, Zhang MZ, Harris RC, Blackwell TS, Zent R, Pozzi A. p47(phox) contributes to albuminuria and kidney fibrosis in mice. Kidney Int 2015; 87:948-62. [PMID: 25565313 PMCID: PMC4425591 DOI: 10.1038/ki.2014.386] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 09/03/2014] [Accepted: 10/01/2014] [Indexed: 12/19/2022]
Abstract
Reactive oxygen species (ROS) have an important pathogenic role in the development of many diseases, including kidney disease. Major ROS generators in the glomerulus of the kidney are the p47(phox)-containing NAPDH oxidases NOX1 and NOX2. The cytosolic p47(phox) subunit is a key regulator of the assembly and function of NOX1 and NOX2 and its expression and phosphorylation are upregulated in the course of renal injury, and have been shown to exacerbate diabetic nephropathy. However, its role in nondiabetic-mediated glomerular injury is unclear. To address this, we subjected p47(phox)-null mice to either adriamycin-mediated or partial renal ablation-mediated glomerular injury. Deletion of p47(phox) protected the mice from albuminuria and glomerulosclerosis in both injury models. Integrin α1-null mice develop more severe glomerulosclerosis compared with wild-type mice in response to glomerular injury mainly due to increased production of ROS. Interestingly, the protective effects of p47(phox) knockout were more profound in p47(phox)/integrin α1 double knockout mice. In vitro analysis of primary mesangial cells showed that deletion of p47(phox) led to reduced basal levels of superoxide and collagen IV production. Thus, p47(phox)-dependent NADPH oxidases are a major glomerular source of ROS, contribute to kidney injury, and are potential targets for antioxidant therapy in fibrotic disease.
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Affiliation(s)
- Hongtao Wang
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Xiwu Chen
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Yan Su
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Paisit Paueksakon
- Department of Pathology, Immunology, and Microbiology, Vanderbilt University, Nashville, Tennessee, USA
| | - Wen Hu
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Ming-Zhi Zhang
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Raymond C Harris
- 1] Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA [2] Department of Medicine, Veterans Affairs Hospitals, Nashville, Tennessee, USA
| | - Timothy S Blackwell
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA
| | - Roy Zent
- 1] Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA [2] Department of Medicine, Veterans Affairs Hospitals, Nashville, Tennessee, USA
| | - Ambra Pozzi
- 1] Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University, Nashville, Tennessee, USA [2] Department of Medicine, Veterans Affairs Hospitals, Nashville, Tennessee, USA
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96
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El-Merahbi R, Liu YN, Eid A, Daoud G, Hosry L, Monzer A, Mouhieddine TH, Hamade A, Najjar F, Abou-Kheir W. Berberis libanotica Ehrenb extract shows anti-neoplastic effects on prostate cancer stem/progenitor cells. PLoS One 2014; 9:e112453. [PMID: 25380390 PMCID: PMC4224486 DOI: 10.1371/journal.pone.0112453] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/08/2014] [Indexed: 01/11/2023] Open
Abstract
Cancer stem cells (CSCs), including those of advanced prostate cancer, are a suggested reason for tumor resistance toward conventional tumor therapy. Therefore, new therapeutic agents are urgently needed for targeting CSCs. Despite the minimal understanding of their modes of action, natural products and herbal therapies have been commonly used in the prevention and treatment of many cancers. Berberis libanotica Ehrenb (BLE) is a plant rich in alkaloids which may possess anti-cancer activity and a high potential for eliminating CSCs. We tested the effect of BLE on prostate cancer cells and our data indicated that this extract induced significant reduction in cell viability and inhibited the proliferation of human prostate cancer cell lines (DU145, PC3 and 22Rv1) in a dose- and time-dependent manner. BLE extract induced a perturbation of the cell cycle, leading to a G0-G1 arrest. Furthermore, we noted 50% cell death, characterized by the production of high levels of reactive oxidative species (ROS). Inhibition of cellular migration and invasion was also achieved upon treatment with BLE extract, suggesting a role in inhibiting metastasis. Interestingly, BLE extract had a major effect on CSCs. Cells were grown in a 3D sphere-formation assay to enrich for a population of cancer stem/progenitor cells. Our results showed a significant reduction in sphere formation ability. Three rounds of treatment with BLE extract were sufficient to eradicate the self-renewal ability of highly resistant CSCs. In conclusion, our results suggest a high therapeutic potential of BLE extract in targeting prostate cancer and its CSCs.
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Affiliation(s)
- Rabih El-Merahbi
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Yen-Nien Liu
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Assaad Eid
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Georges Daoud
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Leina Hosry
- Faculty of Pharmacy, Lebanese University, Hadath, Lebanon
| | - Alissar Monzer
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Tarek H. Mouhieddine
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Aline Hamade
- Department of Biology, Faculty of Sciences II, Lebanese University, Fanar, Lebanon
- * E-mail: (WAK); (FN); (AH)
| | - Fadia Najjar
- Department of Chemistry and Biochemistry, Faculty of Sciences II, Lebanese University, Fanar, Lebanon
- * E-mail: (WAK); (FN); (AH)
| | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- * E-mail: (WAK); (FN); (AH)
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97
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Grahammer F, Wanner N, Huber TB. mTOR controls kidney epithelia in health and disease. Nephrol Dial Transplant 2014; 29 Suppl 1:i9-i18. [PMID: 24493874 DOI: 10.1093/ndt/gft491] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Renal epithelial function is the cornerstone of key excretory processes performed by our kidneys. Most of these tasks need to be tightly controlled to keep our internal environment in balance. Recently, the mTOR signalling network emerged as a key pathway controlling renal epithelial cells from the glomerular tuft along the entire nephron. Both mTOR complexes, mTORC1 and mTORC2, regulate such diverse processes as glomerular filtration and the fine tuning of tubular electrolyte balance. Most importantly, dysregulation of mTOR signalling contributes to prevalent kidney diseases like diabetic nephropathy and cystic kidney disease. The following review shall summarize our current knowledge of the renal epithelial mTOR signalling system under physiological and pathophysiological conditions.
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Affiliation(s)
- Florian Grahammer
- Renal Division, Department of Medicine, University of Freiburg, Freiburg, Germany
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98
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Abstract
Obesity in combination with diabetes and hypertension likely is contributing to the increasing incidence of chronic kidney disease (CKD) in the 21st century worldwide and requires novel insights and strategies for treatment. There is an increasing recognition that the kidney has an important role in the complex inter-organ communication that occurs with the development of inflammation and fibrosis with obesity. Inhibition of the adiponectin-AMPK pathway has now become established as a critical pathway regulating both inflammation and pro-fibrotic pathways for both obesity-related kidney disease and diabetic kidney disease. AMPK regulates NFκB activation and is a potent regulator of NADPH oxidases. Nox4 in particular has emerged as a key contribtor to the early inflammation of diabetic kidney disease. AMPK also regulates several transcription factors that contribute to stimulation of the transforming growth factor-beta (TGF-β) system. Another key aspect of AMPK regulation is its control of mammalian target of rapamycin (mTOR) and mitochondrial biogenesis. Inhibition of PGC-1α, the transcriptional co-activator of mitochondrial biogenesis is being recognized as a key pathway that is inhibited in diabetic kidney disease and may be linked to inhibition of mitochondrial function. Translation of this concept is emerging via the field of urine metabolomics, as several metabolites linked to mitochondria are consistently downregulated in human diabetic kidney disease. Further studies to explore the role of AMPK and related energy-sensing pathways will likely lead to a more comprehensive understanding of why the kidney is affected early on and in a progressive manner with obesity and diabetes.
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Das F, Bera A, Ghosh-Choudhury N, Abboud HE, Kasinath BS, Choudhury GG. TGFβ-induced deptor suppression recruits mTORC1 and not mTORC2 to enhance collagen I (α2) gene expression. PLoS One 2014; 9:e109608. [PMID: 25333702 PMCID: PMC4198127 DOI: 10.1371/journal.pone.0109608] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/02/2014] [Indexed: 02/06/2023] Open
Abstract
Enhanced TGFβ activity contributes to the accumulation of matrix proteins including collagen I (α2) by proximal tubular epithelial cells in progressive kidney disease. Although TGFβ rapidly activates its canonical Smad signaling pathway, it also recruits noncanonical pathway involving mTOR kinase to regulate renal matrix expansion. The mechanism by which chronic TGFβ treatment maintains increased mTOR activity to induce the matrix protein collagen I (α2) expression is not known. Deptor is an mTOR interacting protein that suppresses mTOR activity in both mTORC1 and mTORC2. In proximal tubular epithelial cells, TGFβ reduced deptor levels in a time-dependent manner with concomitant increase in both mTORC1 and mTORC2 activities. Expression of deptor abrogated activity of mTORC1 and mTORC2, resulting in inhibition of collagen I (α2) mRNA and protein expression via transcriptional mechanism. In contrast, neutralization of endogenous deptor by shRNAs increased activity of both mTOR complexes and expression of collagen I (α2) similar to TGFβ treatment. Importantly, downregulation of deptor by TGFβ increased the expression of Hif1α by increasing translation of its mRNA. TGFβ-induced deptor downregulation promotes Hif1α binding to its cognate hypoxia responsive element in the collagen I (α2) gene to control its protein expression via direct transcriptional mechanism. Interestingly, knockdown of raptor to specifically block mTORC1 activity significantly inhibited expression of collagen I (α2) and Hif1α while inhibition of rictor to prevent selectively mTORC2 activation did not have any effect. Critically, our data provide evidence for the requirement of TGFβ-activated mTORC1 only by deptor downregulation, which dominates upon the bystander mTORC2 activity for enhanced expression of collagen I (α2). Our results also suggest the presence of a safeguard mechanism involving deptor-mediated suppression of mTORC1 activity against developing TGFβ-induced renal fibrosis.
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Affiliation(s)
- Falguni Das
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Amit Bera
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Nandini Ghosh-Choudhury
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- VA Research, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
| | - Hanna E. Abboud
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- VA Research, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
| | - Balakuntalam S. Kasinath
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- VA Research, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
| | - Goutam Ghosh Choudhury
- Departments of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- VA Research, South Texas Veterans Health Care System, San Antonio, Texas, United States of America
- * E-mail:
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100
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Das F, Ghosh-Choudhury N, Dey N, Bera A, Mariappan MM, Kasinath BS, Ghosh Choudhury G. High glucose forces a positive feedback loop connecting Akt kinase and FoxO1 transcription factor to activate mTORC1 kinase for mesangial cell hypertrophy and matrix protein expression. J Biol Chem 2014; 289:32703-16. [PMID: 25288788 DOI: 10.1074/jbc.m114.605196] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
High glucose-induced Akt acts as a signaling hub for mesangial cell hypertrophy and matrix expansion, which are recognized as cardinal signatures for the development of diabetic nephropathy. How mesangial cells sustain the activated state of Akt is not clearly understood. Here we show Akt-dependent phosphorylation of the transcription factor FoxO1 by high glucose. Phosphorylation-deficient, constitutively active FoxO1 inhibited the high glucose-induced phosphorylation of Akt to suppress the phosphorylation/inactivation of PRAS40 and mTORC1 activity. In contrast, dominant negative FoxO1 increased the phosphorylation of Akt, resulting in increased mTORC1 activity similar to high glucose treatment. Notably, FoxO1 regulates high glucose-induced protein synthesis, hypertrophy, and expression of fibronectin and PAI-1. High glucose paves the way for complications of diabetic nephropathy through the production of reactive oxygen species (ROS). We considered whether the FoxO1 target antioxidant enzyme catalase contributes to sustained activation of Akt. High glucose-inactivated FoxO1 decreases the expression of catalase to increase the production of ROS. Moreover, we show that catalase blocks high glucose-stimulated Akt phosphorylation to attenuate the inactivation of FoxO1 and PRAS40, resulting in the inhibition of mTORC1 and mesangial cell hypertrophy and fibronectin and PAI-1 expression. Finally, using kidney cortices from type 1 diabetic OVE26 mice, we show that increased FoxO1 phosphorylation is associated with decreased catalase expression and increased fibronectin and PAI-1 expression. Together, our results provide the first evidence for the presence of a positive feedback loop for the sustained activation of Akt involving inactivated FoxO1 and a decrease in catalase expression, leading to increased ROS and mesangial cell hypertrophy and matrix protein expression.
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Affiliation(s)
| | - Nandini Ghosh-Choudhury
- Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 From the Veterans Affairs Research and Geriatric Research and
| | | | | | | | - Balakuntalam S Kasinath
- the Departments of Medicine and From the Veterans Affairs Research and Geriatric Research and
| | - Goutam Ghosh Choudhury
- the Departments of Medicine and From the Veterans Affairs Research and Geriatric Research and Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas 78229 and
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