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Schwartz L, Simoni A, Yan P, Salamon K, Turkoglu A, Vasquez Martinez G, Zepeda-Orozco D, Eichler T, Wang X, Spencer JD. Insulin receptor orchestrates kidney antibacterial defenses. Proc Natl Acad Sci U S A 2024; 121:e2400666121. [PMID: 38976738 PMCID: PMC11260129 DOI: 10.1073/pnas.2400666121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 06/06/2024] [Indexed: 07/10/2024] Open
Abstract
Urinary tract infection (UTI) commonly afflicts people with diabetes. This augmented infection risk is partly due to deregulated insulin receptor (IR) signaling in the kidney collecting duct. The collecting duct is composed of intercalated cells (ICs) and principal cells (PCs). Evidence suggests that ICs contribute to UTI defenses. Here, we interrogate how IR deletion in ICs impacts antibacterial defenses against uropathogenic Escherichia coli. We also explore how IR deletion affects immune responses in neighboring PCs with intact IR expression. To accomplish this objective, we profile the transcriptomes of IC and PC populations enriched from kidneys of wild-type and IC-specific IR knock-out mice that have increased UTI susceptibility. Transcriptomic analysis demonstrates that IR deletion suppresses IC-integrated stress responses and innate immune defenses. To define how IR shapes these immune defenses, we employ murine and human kidney cultures. When challenged with bacteria, murine ICs and human kidney cells with deregulated IR signaling cannot engage central components of the integrated stress response-including activating transcriptional factor 4 (ATF4). Silencing ATF4 impairs NFkB activation and promotes infection. In turn, NFkB silencing augments infection and suppresses antimicrobial peptide expression. In diabetic mice and people with diabetes, collecting duct cells show reduced IR expression, impaired integrated stress response engagement, and compromised immunity. Collectively, these translational data illustrate how IR orchestrates collecting duct antibacterial responses and the communication between ICs and PCs.
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Affiliation(s)
- Laura Schwartz
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
- Division of Nephrology and Hypertension, Department of Pediatrics, Nationwide Children’s, Columbus, OH43205
| | - Aaron Simoni
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
| | - Pearlly Yan
- Comprehensive Cancer Center, Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH43210
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH43210
| | - Kristin Salamon
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
| | - Altan Turkoglu
- Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH43210
| | - Gabriela Vasquez Martinez
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
| | - Diana Zepeda-Orozco
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
- Division of Nephrology and Hypertension, Department of Pediatrics, Nationwide Children’s, Columbus, OH43205
| | - Tad Eichler
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
| | - Xin Wang
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
| | - John David Spencer
- The Kidney and Urinary Tract Center, Abigail Wexner Research Institute at Nationwide Children’s, Columbus, OH43205
- Division of Nephrology and Hypertension, Department of Pediatrics, Nationwide Children’s, Columbus, OH43205
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Schwartz L, Salamon K, Simoni A, Eichler T, Jackson AR, Murtha M, Becknell B, Kauffman A, Linn-Peirano S, Holdsworth N, Tyagi V, Tang H, Rust S, Cortado H, Zabbarova I, Kanai A, Spencer JD. Insulin receptor signaling engages bladder urothelial defenses that limit urinary tract infection. Cell Rep 2024; 43:114007. [PMID: 38517889 DOI: 10.1016/j.celrep.2024.114007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 02/10/2024] [Accepted: 03/11/2024] [Indexed: 03/24/2024] Open
Abstract
Urinary tract infections (UTIs) commonly afflict people with diabetes. To better understand the mechanisms that predispose diabetics to UTIs, we employ diabetic mouse models and altered insulin signaling to show that insulin receptor (IR) shapes UTI defenses. Our findings are validated in human biosamples. We report that diabetic mice have suppressed IR expression and are more susceptible to UTIs caused by uropathogenic Escherichia coli (UPEC). Systemic IR inhibition increases UPEC susceptibility, while IR activation reduces UTIs. Localized IR deletion in bladder urothelium promotes UTI by increasing barrier permeability and suppressing antimicrobial peptides. Mechanistically, IR deletion reduces nuclear factor κB (NF-κB)-dependent programming that co-regulates urothelial tight junction integrity and antimicrobial peptides. Exfoliated urothelial cells or urine samples from diabetic youths show suppressed expression of IR, barrier genes, and antimicrobial peptides. These observations demonstrate that urothelial insulin signaling has a role in UTI prevention and link IR to urothelial barrier maintenance and antimicrobial peptide expression.
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Affiliation(s)
- Laura Schwartz
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Division of Nephrology and Hypertension, Nationwide Children's, Columbus, OH 43205, USA
| | - Kristin Salamon
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Aaron Simoni
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Tad Eichler
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Ashley R Jackson
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Division of Nephrology and Hypertension, Nationwide Children's, Columbus, OH 43205, USA
| | - Matthew Murtha
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Brian Becknell
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Division of Nephrology and Hypertension, Nationwide Children's, Columbus, OH 43205, USA
| | - Andrew Kauffman
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Tulane University, New Orleans, LA 70118, USA
| | - Sarah Linn-Peirano
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Department of Veterinary Biosciences, The Ohio State University College of Veterinary Medicine, Columbus, OH 43210, USA
| | - Natalie Holdsworth
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA
| | - Vidhi Tyagi
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Hancong Tang
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Steve Rust
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Hanna Cortado
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA
| | - Irina Zabbarova
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Anthony Kanai
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - John David Spencer
- The Kidney and Urinary Tract Center, The Abigail Wexner Research Institute at Nationwide Children's, Columbus, OH 43205, USA; Division of Nephrology and Hypertension, Nationwide Children's, Columbus, OH 43205, USA.
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Bosch A, Kannenkeril D, Ott C, Striepe K, Schiffer M, Schmieder RE. Relation between waist circumference and the renal hemodynamic in healthy individuals. Nutr Metab Cardiovasc Dis 2024; 34:755-762. [PMID: 38000996 DOI: 10.1016/j.numecd.2023.10.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/12/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023]
Abstract
BACKGROUND AND AIMS Obesity has been shown to be an independent risk factor for the development of CKD. Little is known about pathways of interaction of visceral fat mass estimated by waist circumference (WC) and metabolic factors with the renal and intraglomerular hemodynamic profile in healthy, non-obese individuals. METHODS AND RESULTS The study population of this post-hoc analysis in 80 healthy individuals, who participated in a randomized, controlled clinical trial (www. CLINICALTRIALS gov: NCT02783456) was divided into two groups based on median of WC (high WC and low WC group). Renal hemodynamic profiles were analyzed using steady state input clearance (infusion of para-amino-hippuric acid and inulin). Intraglomerular pressure (IGP) and resistances of the afferent (RA) and efferent (RE) arterioles were calculated (Gomez equation). The analysis included healthy, non-smoking individuals, aged 27 ± 9 years with median WC of 84.75 ± 9 cm. Glomerular filtration rate (GFR) (110 ± 15 vs. 127 ± 16 ml/min/m2, p < 0.001), renal plasma flow (RPF) (620 ± 109 vs. 700 ± 104 ml/min, p = 0.001) and IGP (36.7 ± 2.3 vs. 38.5 ± 3.1 mmHg, p = 0.003) were lower in the high WC compared to the low WC group. Patients in the high WC group showed higher renal vascular resistance (RVR) (85 ± 19 vs. 70 ± 12 mmHg/(ml/min), p < 0.001), higher RA (4034 ± 1177 vs. 3069 ± 786 dyn∗s/cm5, p < 0.001) and higher RE (2283 ± 339 vs. 2118 ± 280 dyn∗s/cm5, p = 0.021) compared to the low WC group. Individuals in the high WC group showed higher leptin levels (p = 0.003) and higher HOMA-IR (p = 0.024) compared to the low WC group. CONCLUSION Increased WC in healthy young individuals was associated with reduced GFR and RPF likely mediated by increased RVR.
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Affiliation(s)
- Agnes Bosch
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany.
| | - Dennis Kannenkeril
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Christian Ott
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany; Department of Nephrology and Hypertension, Paracelsus Medical School Nuremberg, Nuremberg, Germany
| | - Kristina Striepe
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Mario Schiffer
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
| | - Roland E Schmieder
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Germany
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Alkhaleq HA, Karram T, Fokra A, Hamoud S, Kabala A, Abassi Z. The Protective Pathways Activated in Kidneys of αMUPA Transgenic Mice Following Ischemia\Reperfusion-Induced Acute Kidney Injury. Cells 2023; 12:2497. [PMID: 37887341 PMCID: PMC10605904 DOI: 10.3390/cells12202497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/12/2023] [Accepted: 09/30/2023] [Indexed: 10/28/2023] Open
Abstract
Despite the high prevalence of acute kidney injury (AKI), the therapeutic approaches for AKI are disappointing. This deficiency stems from the poor understanding of the pathogenesis of AKI. Recent studies demonstrate that αMUPA, alpha murine urokinase-type plasminogen activator (uPA) transgenic mice, display a cardioprotective pathway following myocardial ischemia. We hypothesize that these mice also possess protective renal pathways. Male and female αMUPA mice and their wild type were subjected to 30 min of bilateral ischemic AKI. Blood samples and kidneys were harvested 48 h following AKI for biomarkers of kidney function, renal injury, inflammatory response, and intracellular pathways sensing or responding to AKI. αMUPA mice, especially females, exhibited attenuated renal damage in response to AKI, as was evident from lower SCr and BUN, normal renal histology, and attenuated expression of NGAL and KIM-1. Notably, αMUPA females did not show a significant change in renal inflammatory and fibrotic markers following AKI as compared with wild-type (WT) mice and αMUPA males. Moreover, αMUPA female mice exhibited the lowest levels of renal apoptotic and autophagy markers during normal conditions and following AKI. αMUPA mice, especially the females, showed remarkable expression of PGC1α and eNOS following AKI. Furthermore, MUPA mice showed a significant elevation in renal leptin expression before and following AKI. Pretreatment of αMUPA with leptin-neutralizing antibodies prior to AKI abolished their resistance to AKI. Collectively, the kidneys of αMUPA mice, especially those of females, are less susceptible to ischemic I/R injury compared to WT mice, and this is due to nephroprotective actions mediated by the upregulation of leptin, eNOS, ACE2, and PGC1α along with impaired inflammatory, fibrotic, and autophagy processes.
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Affiliation(s)
- Heba Abd Alkhaleq
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel; (H.A.A.); (A.F.); (A.K.)
| | - Tony Karram
- Department of Vascular Surgery, Rambam Health Care Campus, Haifa 3109601, Israel;
| | - Ahmad Fokra
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel; (H.A.A.); (A.F.); (A.K.)
| | - Shadi Hamoud
- Internal Medicine, Rambam Health Care Campus, Haifa 3109601, Israel;
| | - Aviva Kabala
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel; (H.A.A.); (A.F.); (A.K.)
| | - Zaid Abassi
- Department of Physiology and Biophysics, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel; (H.A.A.); (A.F.); (A.K.)
- Laboratory Medicine, Rambam Health Care Campus, Haifa 3109601, Israel
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5
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Zhu Z, Luan G, Peng S, Fang Y, Fang Q, Shen S, Wu K, Qian S, Jia W, Ye J, Wei L. Huangkui capsule attenuates diabetic kidney disease through the induction of mitophagy mediated by STING1/PINK1 signaling in tubular cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 119:154975. [PMID: 37517171 DOI: 10.1016/j.phymed.2023.154975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/29/2023] [Accepted: 07/15/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND Mitochondria is critic to tubulopathy, especially in diabetic kidney disease (DKD). Huangkui capsule (HKC; a new ethanol extract from the dried corolla of Abelmoschus manihot) has significant clinical effect on DKD. Previous studies have shown that HKC protects kidney by regulating mitochondrial function, but its mechanism is still unclear. The latest research found that the stimulator of interferon genes (STING1) signal pathway is closely related to mitophagy. However, whether HKC induces mitophagy through targeting STING1/PTEN-Induced putative kinase (PINK1) in renal tubular remains elusive. OBJECTIVE This study aims to clarify the therapeutic effect of HKC on renal tubular mitophagy in DKD and its potential mechanism in vivo and in vitro. METHODS Forty male C57BL/6 mice were randomly divided into 5 groups: CON group, DKD group, HKC-L (1.0 g/kg/day, by gavage), HKC-H (2.0 g/kg/day), and LST group. Diabetes model was induced by high-fat diet (HFD) combined with intraperitoneal injection of Streptozotocin (STZ). LST (losartan) is used as a positive control drug. Then, the glomeruli, renal tubular lesions, mitochondrial morphology and function of renal tubular cells and mitophagy levels were detected in mice. In addition, a high glucose injury model was established using HK2 human renal tubular cells. Pretreate HK2 cells with HKC or LST and detect mitochondrial function, mitophagy level, and autophagic flux. In addition, small interfering RNAs (siRNAs) of STING1 and PINK1 and overexpressing pcDNA3.1 plasmids were transfected into HK-2 cells to validate the mitophagy mechanism regulated by STING1/PINK1 signaling. RESULTS The ratio of urinary albumin to creatinine (ACR), fasting blood glucose, body weight in the early DKD mice model was increased, with damage to the glomerulus and renal tubules, mitochondrial structure and dysfunction in the renal tubules, and inhibition of STING1/PINK1 mediated mitophagy. Although the fasting blood glucose, body weight and serum creatinine levels were hardly ameliated, high dose HKC (2.0 g/kg/day) treatment significantly reduced ACR in the DKD mice to some extent, improved renal tubular injury, accurately upregulated STING1/PINK1 signaling mediated mitophagy levels, improved autophagic flux, and restored healthy mitochondrial pools. In vitro, an increase in mitochondrial fragments, fusion to fission, ROS and apoptosis, and a decrease in respiratory function, mtDNA, and membrane potential were observed in HK2 cells exposed to high glucose. HKC treatment significantly protected mitochondrial dynamics and function, which is consistent with in vivo results. Further research has shown that HKC can increase the level of mitophagy mediated by STING1/PINK1 in HK2 cells. CONCLUSIONS Our results suggest that HKC ameliorates renal tubulopathy in DKD and induces mitophagy partly through the up-regulation of the STING1/PINK1 pathway. These findings may provide an innovative therapeutic basis for DKD treatment.
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Affiliation(s)
- Zhen Zhu
- Department of Endocrine Medicine, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Guangxin Luan
- Department of Clinical Laboratory, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Shiqiao Peng
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Yunyun Fang
- Department of Endocrine Medicine, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Qiongqiong Fang
- Department of Endocrine Medicine, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Shuang Shen
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Kaiyue Wu
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Shengnan Qian
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Weiping Jia
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China
| | - Jianping Ye
- Shanghai Diabetes Institute, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China; Metabolic Disease Research Center, Zhengzhou University Affiliated Zhengzhou Central Hospital, Zhengzhou 450007, China.
| | - Li Wei
- Department of Endocrine Medicine, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201306, China.
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6
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Haque M, Sinha S. Insulin resistance and type 2 diabetes mellitus chain reaction on renal system. ADVANCES IN HUMAN BIOLOGY 2023. [DOI: 10.4103/aihb.aihb_4_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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7
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Xiong W, Meng XF, Zhang C. NLRP3 Inflammasome in Metabolic-Associated Kidney Diseases: An Update. Front Immunol 2021; 12:714340. [PMID: 34305953 PMCID: PMC8297462 DOI: 10.3389/fimmu.2021.714340] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 06/28/2021] [Indexed: 12/19/2022] Open
Abstract
Metabolic syndrome (MS) is a group of complex metabolic disorders syndrome, which refers to the pathological state of metabolism disorder of protein, fat, carbohydrate and other substances in human body. The kidney is an important organ of metabolism, and various metabolic disorders can lead to the abnormalities in the structure and function of the kidney. The recognition of pathogenesis and treatment measures of renal damage in MS is a very important part for the renal function preserve. Inflammatory response caused by various metabolic factors is a protective mechanism of the body, but persistent inflammation will become a harmful factor and aggravate kidney damage. Inflammasomes are sensors of the innate immune system that play crucial roles in initiating inflammation in response to acute infections and chronic diseases. They are multiprotein complex composed of cytoplasmic sensors (mainly NLR family members), apoptosis-associated speck-like protein (ASC or PYCARD) and pro-caspase-1. After receiving exogenous and endogenous stimuli, the sensors begin to assemble inflammasome and then promote the release of inflammatory cytokines IL-1β and IL-18, resulting in a special way of cell death named pyroptosis. In the kidney, NLRP3 inflammasome can be activated by a variety of pathways, which eventually leads to inflammatory infiltration, renal intrinsic cell damage and renal function decline. This paper reviews the function and specific regulatory mechanism of inflammasome in kidney damage caused by various metabolic disorders, which will provide a new therapeutic perspective and targets for kidney diseases.
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Affiliation(s)
- Wei Xiong
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xian-Fang Meng
- Department of Neurobiology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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8
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Pathophysiology of diabetic kidney disease: impact of SGLT2 inhibitors. Nat Rev Nephrol 2021; 17:319-334. [PMID: 33547417 DOI: 10.1038/s41581-021-00393-8] [Citation(s) in RCA: 244] [Impact Index Per Article: 81.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 01/30/2023]
Abstract
Diabetic kidney disease is the leading cause of kidney failure worldwide; in the USA, it accounts for over 50% of individuals entering dialysis or transplant programmes. Unlike other complications of diabetes, the prevalence of diabetic kidney disease has failed to decline over the past 30 years. Hyperglycaemia is the primary aetiological factor responsible for the development of diabetic kidney disease. Once hyperglycaemia becomes established, multiple pathophysiological disturbances, including hypertension, altered tubuloglomerular feedback, renal hypoxia, lipotoxicity, podocyte injury, inflammation, mitochondrial dysfunction, impaired autophagy and increased activity of the sodium-hydrogen exchanger, contribute to progressive glomerular sclerosis and the decline in glomerular filtration rate. The quantitative contribution of each of these abnormalities to the progression of diabetic kidney disease, as well as their role in type 1 and type 2 diabetes mellitus, remains to be determined. Sodium-glucose co-transporter 2 (SGLT2) inhibitors have a beneficial impact on many of these pathophysiological abnormalities; however, as several pathophysiological disturbances contribute to the onset and progression of diabetic kidney disease, multiple agents used in combination will likely be required to slow the progression of disease effectively.
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9
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Zhao J, Tan C, Imai R, Ukon N, Shimoyama S, Maejima Y, Omiya Y, Takahashi K, Ito H, Nan G, Zhao S, Shimomura K. Evaluation of organ glucose metabolism by 18F-FDG accumulation with insulin loading in aged mice compared with young normal mice. Sci Rep 2021; 11:7421. [PMID: 33795778 PMCID: PMC8016832 DOI: 10.1038/s41598-021-86825-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/17/2021] [Indexed: 12/20/2022] Open
Abstract
It is important to determine the functional changes of organs that occur as a result of aging, the understanding of which may lead to the maintenance of a healthy life. Glucose metabolism in healthy bodies is one of the potential markers used to evaluate the changes of organ function. Thus, information about normal organ glucose metabolism may help to understand the functional changes of organs. [18F]-Fluoro-2-deoxy-2-d-glucose (18F-FDG), a glucose analog, has been used to measure glucose metabolism in various fields, such as basic medical research and drug discovery. However, glucose metabolism changes in aged animals have not yet been fully clarified. The aim of this study is to evaluate changes in glucose metabolism in organs and brain regions by measuring 18F-FDG accumulation and 18F-FDG autoradiography with insulin loading in aged and young wild-type mice. In the untreated groups, the levels of 18F-FDG accumulation in the blood, plasma, muscle, lungs, spleen, pancreas, testes, stomach, small intestine, kidneys, liver, brain, and brain regions, namely, the cortex, striatum, thalamus, and hippocampus, were all significantly higher in the aged mice. The treated group showed lower 18F-FDG accumulation levels in the pancreas and kidneys, as well as in the cortex, striatum, thalamus, and hippocampus in the aged mice than the untreated groups, whereas higher 18F-FDG accumulation levels were observed in those in the young mice. These results demonstrate that insulin loading decreases effect on 18F-FDG accumulation levels in some organs of the aged mice. Therefore, aging can increase insulin resistance and lead to systemic glucose metabolism dysfunction.
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Affiliation(s)
- Jingmin Zhao
- Department of Neurology, China-Japan Union Hospital of Jilin University, 126 XianTai Street, Changchun, 130031, Jilin, China.,Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima, Japan
| | - Chengbo Tan
- Department of Neurosurgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.,Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Ryota Imai
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University, Fukushima, Japan.,Tsumura Kampo Research Laboratories, Kampo Research & Development Division, Tsumura & Co., Ibaraki, Japan
| | - Naoyuki Ukon
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Saki Shimoyama
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Yuko Maejima
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University, Fukushima, Japan
| | - Yuji Omiya
- Tsumura Kampo Research Laboratories, Kampo Research & Development Division, Tsumura & Co., Ibaraki, Japan
| | - Kazuhiro Takahashi
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Hiroshi Ito
- Department of Radiology and Nuclear Medicine, Fukushima Medical University, Fukushima, Japan.,Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Guangxian Nan
- Department of Neurology, China-Japan Union Hospital of Jilin University, 126 XianTai Street, Changchun, 130031, Jilin, China.
| | - Songji Zhao
- Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Fukushima, 960-1295, Japan. .,Basic Medical College of Jilin University, Changchun, China.
| | - Kenju Shimomura
- Department of Bioregulation and Pharmacological Medicine, Fukushima Medical University, Fukushima, Japan
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10
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Lee HJ, Mariappan MM, Norton L, Bakewell T, Feliers D, Oh SB, Donati A, Rubannelsonkumar CS, Venkatachalam MA, Harris SE, Rubera I, Tauc M, Ghosh Choudhury G, Kahn CR, Sharma K, DeFronzo RA, Kasinath BS. Proximal tubular epithelial insulin receptor mediates high-fat diet-induced kidney injury. JCI Insight 2021; 6:143619. [PMID: 33400689 PMCID: PMC7934847 DOI: 10.1172/jci.insight.143619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/29/2020] [Indexed: 01/04/2023] Open
Abstract
The role of insulin receptor (IR) activated by hyperinsulinemia in obesity-induced kidney injury is not well understood. We hypothesized that activation of kidney proximal tubule epithelial IR contributes to obesity-induced kidney injury. We administered normal-fat diet (NFD) or high-fat diet (HFD) to control and kidney proximal tubule IR–knockout (KPTIRKO) mice for 4 months. Renal cortical IR expression was decreased by 60% in male and female KPTIRKO mice. Baseline serum glucose, serum creatinine, and the ratio of urinary albumin to creatinine (ACR) were similar in KPTIRKO mice compared to those of controls. On HFD, weight gain and increase in serum cholesterol were similar in control and KPTIRKO mice; blood glucose did not change. HFD increased the following parameters in the male control mice: renal cortical contents of phosphorylated IR and Akt, matrix proteins, urinary ACR, urinary kidney injury molecule-1–to-creatinine ratio, and systolic blood pressure. Renal cortical generation of hydrogen sulfide was reduced in HFD-fed male control mice. All of these parameters were ameliorated in male KPTIRKO mice. Interestingly, female mice were resistant to HFD-induced kidney injury in both genotypes. We conclude that HFD-induced kidney injury requires renal proximal tubule IR activation in male mice.
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Affiliation(s)
- Hak Joo Lee
- Center for Renal Medicine, Division of Nephrology
| | | | - Luke Norton
- Division of Diabetes, Department of Medicine
| | | | | | - Sae Byeol Oh
- Center for Renal Medicine, Division of Nephrology
| | | | | | | | - Stephen E Harris
- Department of Periodontics, University of Texas Health, San Antonio, Texas, USA
| | - Isabelle Rubera
- Universite Cote d'Azur, CNRS - UMR-7370, Laboratoire de Physiomédecine Moléculaire, Nice, France
| | - Michel Tauc
- Universite Cote d'Azur, CNRS - UMR-7370, Laboratoire de Physiomédecine Moléculaire, Nice, France
| | - Goutam Ghosh Choudhury
- Center for Renal Medicine, Division of Nephrology.,VA Research and.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
| | - C Ronald Kahn
- Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Kumar Sharma
- Center for Renal Medicine, Division of Nephrology.,VA Research and
| | | | - Balakuntalam S Kasinath
- Center for Renal Medicine, Division of Nephrology.,VA Research and.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
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11
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He C, Ruan F, Jiang S, Zeng J, Yin H, Liu R, Zhang Y, Huang L, Wang C, Ma S, Zuo Z. Black Phosphorus Quantum Dots Cause Nephrotoxicity in Organoids, Mice, and Human Cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2001371. [PMID: 32338439 DOI: 10.1002/smll.202001371] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/27/2020] [Accepted: 04/02/2020] [Indexed: 05/12/2023]
Abstract
Quantum dots (QDs) have numerous potential applications in lighting, engineering, and biomedicine. QDs are mainly excreted through the kidney due to their ultrasmall sizes; thus, the kidneys are target organs of QD toxicity. Here, an organoid screening platform is established and used to study the nephrotoxicity of QDs. Organoids are templated from monodisperse microfluidic Matrigel droplets and found to be homogeneous in both tissue structure and functional recapitulation within a population and suitable for the quantitative screening of toxic doses. Kidney organoids are proved displaying higher sensitivity than 2D-cultured cell lines. Similar to metal-containing QDs, black phosphorus (BP)-QDs are found to have moderate toxicity in the kidney organoids. The nephrotoxicity of BP-QDs are validated in both mice and human renal tubular epithelial cells. BP-QDs are also found to cause insulin insensitivity and endoplasmic reticulum (ER) stress in the kidney. Furthermore, ER stress-related IRE1α signaling is shown to mediate renal toxicity and insulin insensitivity caused by BP-QDs. In summary, this work demonstrates the use of constructed kidney organoids as 3D high-throughput screening tools to assess nanosafety and further illuminates the effects and molecular mechanisms of BP-QD nephrotoxicity. The findings will hopefully enable improvement of the safety of BP-QD applications.
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Affiliation(s)
- Chengyong He
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Fengkai Ruan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Xiamen University, Xiamen, Fujian, 361102, China
| | - Shengwei Jiang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Jie Zeng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Hanying Yin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Rong Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Xiamen University, Xiamen, Fujian, 361102, China
| | - Yongxing Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Xiamen University, Xiamen, Fujian, 361102, China
| | - Laiqiang Huang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Chonggang Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Shaohua Ma
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, 518055, China
| | - Zhenghong Zuo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, 361005, China
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12
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Marre M. Importance of intensive blood pressure control in type 2 diabetes: Mechanisms, treatments and current guidelines. Diabetes Obes Metab 2020; 22 Suppl 2:33-42. [PMID: 32250521 DOI: 10.1111/dom.13975] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 02/06/2023]
Abstract
Observational and interventional studies have shown that intensified blood pressure (BP) reduction can benefit people with diabetes. Because of their special haemodynamic properties, renin-angiotensin-aldosterone system (RAAS) blockers are recommended. The results of the BP arm of the ADVANCE study strongly support the recently updated European Society of Cardiology/European Association of Diabetes recommendations for the treatment of BP in people with diabetes, which recommend a target systolic/diastolic BP of 130/80 mmHg with few exceptions, and a fixed combination of an RAAS blocker with a diuretic or a calcium channel blocker as first-line treatment.
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Affiliation(s)
- Michel Marre
- INSERM U1138, Centre de Recherches des Cordeliers, Paris, France
- Sorbonne Paris Cité, UFR de Médecine, Université Paris Diderot, Paris, France
- Diabetes Clinic, Centre Médico-Chirurgical Ambroise Paré, Neuilly-sur-Seine, France
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13
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Klemens CA, Brands MW, Staruschenko A. Postprandial effects on electrolyte homeostasis in the kidney. Am J Physiol Renal Physiol 2019; 317:F1405-F1408. [PMID: 31566434 DOI: 10.1152/ajprenal.00350.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Insulin is known to be an important regulator of a number of different channels and transporters in the kidney, but its role in the kidney to prevent Na+ and volume loss during the osmotic load after a meal has only recently been validated. With increasing numbers of people suffering from diabetes and hypertension, furthering our understanding of insulin signaling and renal Na+ handling in both normal and diseased states is essential for improving patient treatments and outcomes. The present review is focused on postprandial effects on Na+ reabsorption in the kidney and the role of the epithelial Na+ channels as an important channel contributing to insulin-mediated Na+ reclamation.
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Affiliation(s)
- Christine A Klemens
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Michael W Brands
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin.,Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
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14
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Wiedenmann T, Dietrich N, Fleming T, Altamura S, Deelman LE, Henning RH, Muckenthaler MU, Nawroth PP, Hammes HP, Wagner AH, Hecker M. Modulation of glutathione peroxidase activity by age-dependent carbonylation in glomeruli of diabetic mice. J Diabetes Complications 2018; 32:130-138. [PMID: 29223856 DOI: 10.1016/j.jdiacomp.2017.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/09/2017] [Accepted: 11/18/2017] [Indexed: 12/29/2022]
Abstract
AIMS Low levels of reactive oxygen species and resulting oxidative protein modifications may play a beneficial role in cellular function under stress conditions. Here we studied the influence of age-dependent protein carbonylation on expression and activity of the anti-oxidative selenoenzyme glutathione peroxidase (GPx) in insulin-deficient Ins2Akita mice and type 2 diabetic obese db/db mice in context of diabetic nephropathy. METHODS Protein carbonylation, GPx expression and activity were examined in kidney tissue and lysates by common histological and protein biochemical methods. RESULTS In kidneys of Ins2Akita mice, carbonylated proteins, GPx-1 and GPx-4 expression were mainly detected in podocytes and mesangial cells. GPx activity was increased in kidney cortex homogenates of these mice. Remarkably, young animals did not show a concomitant increase in GPx expression but enhanced GPx carbonylation. No carbonylation-dependent modification of GPx activity was detected in db/db mice. In cultured podocytes hyperglycemia induced an increase in GPx expression but had no effect on activity or carbonylation. In kidney tissue sections of type 1 or type 2 diabetes patients, GPx-1 and GPx-4 expression but not overall protein carbonylation was significantly decreased. CONCLUSIONS These results indicate the existence of a threshold for beneficial carbonylation-dependent redox signaling during the progression of diabetic nephropathy.
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Affiliation(s)
- Tanja Wiedenmann
- Department of Cardiovascular Physiology, Heidelberg University, Germany
| | | | - Thomas Fleming
- Department of Internal Medicine I and Clinical Chemistry, Heidelberg University Hospital, Germany
| | - Sandro Altamura
- Department of Pediatric Hematology, Oncology and Immunology, Heidelberg University, Germany
| | - Leo E Deelman
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Rob H Henning
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Martina U Muckenthaler
- Department of Pediatric Hematology, Oncology and Immunology, Heidelberg University, Germany
| | - Peter P Nawroth
- Department of Internal Medicine I and Clinical Chemistry, Heidelberg University Hospital, Germany; German Center for Diabetes Research (DZD); Joint Heidelberg-IDC Translational Diabetes Program, Helmholtz-Zentrum, München, Germany
| | | | - Andreas H Wagner
- Department of Cardiovascular Physiology, Heidelberg University, Germany.
| | - Markus Hecker
- Department of Cardiovascular Physiology, Heidelberg University, Germany
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15
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Yang Y, Chen C, Fu C, Xu Z, Lan C, Zeng Y, Chen Z, Jose PA, Zhang Y, Zeng C. Angiotensin II type 2 receptor inhibits expression and function of insulin receptor in rat renal proximal tubule cells. ACTA ACUST UNITED AC 2017; 12:135-145. [PMID: 29289466 DOI: 10.1016/j.jash.2017.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 11/08/2017] [Accepted: 11/25/2017] [Indexed: 11/28/2022]
Abstract
Both renin-angiotensin systems and insulin participate in kidney-involved blood pressure regulation. Activation of angiotensin II type 2 receptor (AT2R) decreases sodium reabsorption in renal proximal tubule (RPT) cells, whereas insulin produces the opposite effect. We presume that AT2R has an inhibitory effect on insulin receptor expression in RPT cells, which may affect renal sodium transport and therefore be of physiological or pathological significance. Our present study found that activation of AT2R inhibited insulin receptor expression in a concentration and time-dependent manner in RPT cells from Wistar-Kyoto (WKY) rats. In the presence of a protein kinase C (PKC) inhibitor (PKC inhibitor peptide 19-31, 10-6 mol/L) or a phosphatidylinositol 3 kinase inhibitor (wortmannin, 10-6 mol/L), the inhibitory effect of AT2R on insulin receptor was blocked, indicating that both PKC and phosphatidylinositol 3 kinase were involved in the signaling pathway. There was a linkage between AT2R and insulin receptor which was determined by both laser confocal microscopy and coimmunoprecipitation. However, the effect of AT2R activation on insulin receptor expression was different in RPT cells from spontaneously hypertensive rats (SHRs). Being contrary to the effect in WKY RPT cells, AT2R stimulation increased insulin receptor in SHR RPT cells. Insulin (10-7 mol/L, 15 minutes) enhanced Na+-K+-ATPase activity in both WKY and SHR RPT cells. Pretreatment with CGP42112 decreased the stimulatory effect of insulin on Na+-K+-ATPase activity in WKY RPT cells, whereas pretreatment with CGP42112 increased it in SHR RPT cells. It is suggested that activation of AT2R inhibits insulin receptor expression and function in RPT cells. The lost inhibitory effect of AT2R on insulin receptor expression may contribute to the pathophysiology of hypertension.
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Affiliation(s)
- Yang Yang
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Caiyu Chen
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Chunjiang Fu
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Zaicheng Xu
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Cong Lan
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Yongchun Zeng
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Zhi Chen
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
| | - Pedro A Jose
- Division of Renal Disease & Hypertension, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Ye Zhang
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China.
| | - Chunyu Zeng
- Department of Cardiology, Chongqing Institute of Cardiology, Chongqing Cardiovascular Disease Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China.
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16
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Horita S, Nakamura M, Suzuki M, Satoh N, Suzuki A, Homma Y, Nangaku M. The role of renal proximal tubule transport in the regulation of blood pressure. Kidney Res Clin Pract 2017; 36:12-21. [PMID: 28428931 PMCID: PMC5331971 DOI: 10.23876/j.krcp.2017.36.1.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/18/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022] Open
Abstract
The electrogenic sodium/bicarbonate cotransporter 1 (NBCe1) on the basolateral side of the renal proximal tubule plays a pivotal role in systemic acid-base homeostasis. Mutations in the gene encoding NBCe1 cause severe proximal renal tubular acidosis accompanied by other extrarenal symptoms. The proximal tubule reabsorbs most of the sodium filtered in the glomerulus, contributing to the regulation of plasma volume and blood pressure. NBCe1 and other sodium transporters in the proximal tubule are regulated by hormones, such as angiotensin II and insulin. Angiotensin II is probably the most important stimulator of sodium reabsorption. Proximal tubule AT1A receptor is crucial for the systemic pressor effect of angiotensin II. In rodents and rabbits, the effect on proximal tubule NBCe1 is biphasic; at low concentration, angiotensin II stimulates NBCe1 via PKC/cAMP/ERK, whereas at high concentration, it inhibits NBCe1 via NO/cGMP/cGKII. In contrast, in human proximal tubule, angiotensin II has a dose-dependent monophasic stimulatory effect via NO/cGMP/ERK. Insulin stimulates the proximal tubule sodium transport, which is IRS2-dependent. We found that in insulin resistance and overt diabetic nephropathy, stimulatory effect of insulin on proximal tubule transport was preserved. Our results suggest that the preserved stimulation of the proximal tubule enhances sodium reabsorption, contributing to the pathogenesis of hypertension with metabolic syndrome. We describe recent findings regarding the role of proximal tubule transport in the regulation of blood pressure, focusing on the effects of angiotensin II and insulin.
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Affiliation(s)
- Shoko Horita
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Motonobu Nakamura
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masashi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Nobuhiko Satoh
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Atsushi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Yukio Homma
- Department of Urology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
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17
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Abstract
Insulin resistance is a systemic disorder that affects many organs and insulin-regulated pathways. The disorder is characterized by a reduced action of insulin despite increased insulin concentrations (hyperinsulinaemia). The effects of insulin on the kidney and vasculature differ in part from the effects on classical insulin target organs. Insulin causes vasodilation by enhancing endothelial nitric oxide production through activation of the phosphatidylinositol 3-kinase pathway. In insulin-resistant states, this pathway is impaired and the mitogen-activated protein kinase pathway stimulates vasoconstriction. The action of insulin on perivascular fat tissue and the subsequent effects on the vascular wall are not fully understood, but the hepatokine fetuin-A, which is released by fatty liver, might promote the proinflammatory effects of perivascular fat. The strong association of salt-sensitive arterial hypertension with insulin resistance indicates an involvement of the kidney in the insulin resistance syndrome. The insulin receptor is expressed on renal tubular cells and podocytes and insulin signalling has important roles in podocyte viability and tubular function. Renal sodium transport is preserved in insulin resistance and contributes to the salt-sensitivity of blood pressure in hyperinsulinaemia. Therapeutically, renal and vascular insulin resistance can be improved by an integrated holistic approach aimed at restoring overall insulin sensitivity and improving insulin signalling.
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18
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Zaika O, Tomilin V, Mamenko M, Bhalla V, Pochynyuk O. New perspective of ClC-Kb/2 Cl- channel physiology in the distal renal tubule. Am J Physiol Renal Physiol 2016; 310:F923-30. [PMID: 26792067 PMCID: PMC5002062 DOI: 10.1152/ajprenal.00577.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/14/2016] [Indexed: 12/17/2022] Open
Abstract
Since its identification as the underlying molecular cause of Bartter's syndrome type 3, ClC-Kb (ClC-K2 in rodents, henceforth it will be referred as ClC-Kb/2) is proposed to play an important role in systemic electrolyte balance and blood pressure regulation by controlling basolateral Cl(-) exit in the distal renal tubular segments from the cortical thick ascending limb to the outer medullary collecting duct. Considerable experimental and clinical effort has been devoted to the identification and characterization of disease-causing mutations as well as control of the channel by its cofactor, barttin. However, we have only begun to unravel the role of ClC-Kb/2 in different tubular segments and to reveal the regulators of its expression and function, e.g., insulin and IGF-1. In this review we discuss recent experimental evidence in this regard and highlight unexplored questions critical to understanding ClC-Kb/2 physiology in the kidney.
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Affiliation(s)
- Oleg Zaika
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Mykola Mamenko
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University, Stanford, California
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas; and
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19
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Selective Insulin Resistance in the Kidney. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5825170. [PMID: 27247938 PMCID: PMC4876201 DOI: 10.1155/2016/5825170] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/04/2016] [Accepted: 04/07/2016] [Indexed: 12/12/2022]
Abstract
Insulin resistance has been characterized as attenuation of insulin sensitivity at target organs and tissues, such as muscle and fat tissues and the liver. The insulin signaling cascade is divided into major pathways such as the PI3K/Akt pathway and the MAPK/MEK pathway. In insulin resistance, however, these pathways are not equally impaired. For example, in the liver, inhibition of gluconeogenesis by the insulin receptor substrate (IRS) 2 pathway is impaired, while lipogenesis by the IRS1 pathway is preserved, thus causing hyperglycemia and hyperlipidemia. It has been recently suggested that selective impairment of insulin signaling cascades in insulin resistance also occurs in the kidney. In the renal proximal tubule, insulin signaling via IRS1 is inhibited, while insulin signaling via IRS2 is preserved. Insulin signaling via IRS2 continues to stimulate sodium reabsorption in the proximal tubule and causes sodium retention, edema, and hypertension. IRS1 signaling deficiency in the proximal tubule may impair IRS1-mediated inhibition of gluconeogenesis, which could induce hyperglycemia by preserving glucose production. In the glomerulus, the impairment of IRS1 signaling deteriorates the structure and function of podocyte and endothelial cells, possibly causing diabetic nephropathy. This paper mainly describes selective insulin resistance in the kidney, focusing on the proximal tubule.
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20
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Ribback S, Cigliano A, Kroeger N, Pilo MG, Terracciano L, Burchardt M, Bannasch P, Calvisi DF, Dombrowski F. PI3K/AKT/mTOR pathway plays a major pathogenetic role in glycogen accumulation and tumor development in renal distal tubules of rats and men. Oncotarget 2016; 6:13036-48. [PMID: 25948777 PMCID: PMC4536997 DOI: 10.18632/oncotarget.3675] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 04/06/2015] [Indexed: 01/13/2023] Open
Abstract
Activation of the PI3K/AKT/mTOR pathway is a crucial molecular event in human clear cell renal cell carcinoma (ccRCC), and is also upregulated in diabetic nephropathy. In diabetic rats metabolic changes affect the renal distal tubular epithelium and lead to glycogen-storing Armanni-Ebstein lesions (AEL), precursor lesions of RCC in the diabetes induced nephrocarcinogenesis model. These lesions resemble human sporadic clear cell tubules (CCT) and tumor cells of human ccRCC. Human sporadic CCT were examined in a collection of 324 nephrectomy specimen, in terms of morphologic, metabolic and molecular alterations, and compared to preneoplastic CCT and RCC developed in the rat following streptozotocin-induced diabetes or N-Nitrosomorpholine administration. Diabetic and non-diabetic rats were subjected to the dual PI3K/mTOR inhibitor, NVP/BEZ235. Human sporadic CCT could be detected in 17.3% of kidney specimens. Human and rat renal CCT display a strong induction of the PI3K/AKT/mTOR pathway and related metabolic alterations. Proteins involved in glycolysis and de novo lipogenesis were upregulated. In in vivo experiments, dual inhibition of PI3K and mTOR resulted in a reduction of proliferation of rat diabetes related CCT and increased autophagic activity. The present data indicate that human sporadic CCT exhibit a pattern of morphologic and metabolic alterations similar to preneoplastic lesions in the rat model. Activation of the PI3K/AKT/mTOR pathway in glycogenotic tubuli is a remarkable molecular event and suggests a preneoplastic character of these lesions also in humans.
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Affiliation(s)
- Silvia Ribback
- Institut für Pathologie, Universitätsmedizin Greifswald, Germany
| | - Antonio Cigliano
- Institut für Pathologie, Universitätsmedizin Greifswald, Germany
| | - Nils Kroeger
- Klinik für Urologie, Universitätsmedizin Greifswald, Germany
| | - Maria G Pilo
- Institut für Pathologie, Universitätsmedizin Greifswald, Germany
| | - Luigi Terracciano
- Molekularpathologie, Institut für Pathologie, Universitätsspital Basel, Switzerland
| | | | | | - Diego F Calvisi
- Institut für Pathologie, Universitätsmedizin Greifswald, Germany
| | - Frank Dombrowski
- Institut für Pathologie, Universitätsmedizin Greifswald, Germany
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21
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Zaika O, Palygin O, Tomilin V, Mamenko M, Staruschenko A, Pochynyuk O. Insulin and IGF-1 activate Kir4.1/5.1 channels in cortical collecting duct principal cells to control basolateral membrane voltage. Am J Physiol Renal Physiol 2016; 310:F311-21. [PMID: 26632606 PMCID: PMC4839479 DOI: 10.1152/ajprenal.00436.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/30/2015] [Indexed: 01/12/2023] Open
Abstract
Potassium Kir4.1/5.1 channels are abundantly expressed at the basolateral membrane of principal cells in the cortical collecting duct (CCD), where they are thought to modulate transport rates by controlling transepithelial voltage. Insulin and insulin-like growth factor-1 (IGF-1) stimulate apically localized epithelial sodium channels (ENaC) to augment sodium reabsorption in the CCD. However, little is known about their actions on potassium channels localized at the basolateral membrane. In this study, we implemented patch-clamp analysis in freshly isolated murine CCD to assess the effect of these hormones on Kir4.1/5.1 at both single channel and cellular levels. We demonstrated that K(+)-selective conductance via Kir4.1/5.1 is the major contributor to the macroscopic current recorded from the basolateral side in principal cells. Acute treatment with 10 μM amiloride (ENaC blocker), 100 nM tertiapin-Q (TPNQ; ROMK inhibitor), and 100 μM ouabain (Na(+)-K(+)-ATPase blocker) failed to produce a measurable effect on the macroscopic current. In contrast, Kir4.1 inhibitor nortriptyline (100 μM), but not fluoxetine (100 μM), virtually abolished whole cell K(+)-selective conductance. Insulin (100 nM) markedly increased the open probability of Kir4.1/5.1 and nortriptyline-sensitive whole cell current, leading to significant hyperpolarization of the basolateral membrane. Inhibition of the phosphatidylinositol 3-kinase cascade with LY294002 (20 μM) abolished action of insulin on Kir4.1/5.1. IGF-1 had similar stimulatory actions on Kir4.1/5.1-mediated conductance only when applied at a higher (500 nM) concentration and was ineffective at 100 nM. We concluded that both insulin and, to a lesser extent, IGF-1 activate Kir4.1/5.1 channel activity and open probability to hyperpolarize the basolateral membrane, thereby facilitating Na(+) reabsorption in the CCD.
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Affiliation(s)
- Oleg Zaika
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Viktor Tomilin
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas; Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russian Federation
| | - Mykola Mamenko
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | | | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas;
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22
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Marlais M, Coward RJ. Paediatrics, insulin resistance and the kidney. Pediatr Nephrol 2015; 30:1217-24. [PMID: 25060762 DOI: 10.1007/s00467-014-2890-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 04/05/2014] [Accepted: 04/15/2014] [Indexed: 12/12/2022]
Abstract
Systemic insulin resistance is becoming more prevalent in the young due to modern lifestyles predisposing to the metabolic syndrome and obesity. There is also evidence that there are critical insulin-resistant phases for the developing child, including puberty, and that renal disease per se causes systemic insulin resistance. This review considers the factors that render children insulin resistant, as well as the accumulating evidence that the kidney is an insulin-responsive organ and could be affected by insulin resistance.
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Affiliation(s)
- Matko Marlais
- Institute of Child Health, University College London, London, United Kingdom
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23
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Hartog H, May CJH, Corbett C, Phillips A, Tomlinson JW, Mergental H, Isaac J, Bramhall S, Mirza DF, Muiesan P, Perera MTPR. Early occurrence of new-onset diabetes after transplantation is related to type of liver graft and warm ischaemic injury. Liver Int 2015; 35:1739-47. [PMID: 25349066 DOI: 10.1111/liv.12706] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 10/20/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS We studied new-onset diabetes after transplantation (NODAT) in liver transplantation with grafts donated after brain death (DBD) or circulatory death (DCD), focusing on the early post-transplant period. METHODS A total of 430 non-diabetic primary liver transplant recipients [DCD, n = 90 (21%)] were followed up for 30 months (range 5-69). NODAT was defined as the composite endpoint of one of following: (i) Two non-fasting plasma glucose levels > 11.1 mmol/L ≥ 30 days apart, (ii) oral hypoglycaemic drugs ≥ 30 days consecutively (iii) insulin therapy ≥ 30 days and (iv) HbA1c ≥ 48 mmol/L. Resolution of NODAT was defined as cessation of treatment or hyperglycaemia. RESULTS Total of 81/430 (19%) patients developed NODAT. Incidence and resolution of NODAT over time showed significantly different patterns between DCD and DBD liver graft recipients; early occurrence, high peak incidence and early resolution were seen in DCD. In multivariate logistic regression including age, ethnicity, HCV, tacrolimus level and pulsed steroids, only DCD was independently associated with NODAT at day 15 post-transplant (OR 6.5, 95% CI 2.3-18.4, P < 0.001), whereas age and pulsed steroids were significant factors between 30-90 days. Combined in multivariate Cox regression model for NODAT-free survival, graft type, age and pulsed steroids were each independent predictor for decreased NODAT-free survival in the first 90-postoperative days. CONCLUSION Early peak of NODAT in DCD graft recipients is a novel finding, occurring independently from known risk factors. Donor warm ischaemia and impact on insulin sensitivity should be further studied and could perhaps be associated with graft function.
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Affiliation(s)
- Hermien Hartog
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Christine J H May
- Diabetes Center, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Chris Corbett
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Angela Phillips
- Diabetes Center, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Jeremy W Tomlinson
- Institute of Biomedical research, University of Birmingham, Birmingham, UK
| | - Hynek Mergental
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - John Isaac
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Simon Bramhall
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Darius F Mirza
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
| | - Paolo Muiesan
- Liver Unit, Queen Elizabeth Hospital Birmingham, Edgbaston, Birmingham, UK
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24
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Rao A, Pandya V, Whaley-Connell A. Obesity and insulin resistance in resistant hypertension: implications for the kidney. Adv Chronic Kidney Dis 2015; 22:211-7. [PMID: 25908470 DOI: 10.1053/j.ackd.2014.12.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 12/08/2014] [Accepted: 12/19/2014] [Indexed: 12/12/2022]
Abstract
There is recognition that the obesity epidemic contributes substantially to the increasing incidence of CKD and resistant hypertension (HTN). The mechanisms by which obesity promotes resistance are an area of active interest and intense investigation. It is thought that increases in visceral adiposity lead to a proinflammatory, pro-oxidative milieu that promote resistance to the metabolic actions of insulin. This resistance to insulin at the level of skeletal muscle tissue impairs glucose disposal/utilization through actions on the endothelium that include vascular rarefaction, reductions in vascular relaxation, and vascular remodeling. Insulin resistance derived from increased adipose tissue and obesity has system-wide implications for other tissue beds such as the kidney that affects blood pressure regulation. The additional autocrine and paracrine activities of adipose tissue contribute to inappropriate activation of the renin-angiotensin-aldosterone system and the sympathetic nervous system that promote kidney microvascular remodeling, stiffness, and sodium (Na(+)) retention that in turn promote HTN and in the CKD patient, resistance. In this review, we will summarize the important mechanisms that link obesity to CKD as they relate to resistant HTN.
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25
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Defective podocyte insulin signalling through p85-XBP1 promotes ATF6-dependent maladaptive ER-stress response in diabetic nephropathy. Nat Commun 2015; 6:6496. [PMID: 25754093 PMCID: PMC4366504 DOI: 10.1038/ncomms7496] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 02/03/2015] [Indexed: 02/08/2023] Open
Abstract
Endoplasmic reticulum (ER) stress is associated with diabetic nephropathy (DN), but its pathophysiological relevance and the mechanisms that compromise adaptive ER signalling in podocytes remain unknown. Here we show that nuclear translocation of the transcription factor spliced X-box binding protein-1 (sXBP1) is selectively impaired in DN, inducing activating transcription factor-6 (ATF6) and C/EBP homology protein (CHOP). Podocyte-specific genetic ablation of XBP1 or inducible expression of ATF6 in mice aggravates DN. sXBP1 lies downstream of insulin signalling and attenuating podocyte insulin signalling by genetic ablation of the insulin receptor or the regulatory subunits phosphatidylinositol 3-kinase (PI3K) p85α or p85β impairs sXBP1 nuclear translocation and exacerbates DN. Corroborating our findings from murine DN, the interaction of sXBP1 with p85α and p85β is markedly impaired in the glomerular compartment of human DN. Thus, signalling via the insulin receptor, p85, and XBP1 maintains podocyte homeostasis, while disruption of this pathway impairs podocyte function in DN.
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26
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Ilatovskaya DV, Levchenko V, Brands MW, Pavlov TS, Staruschenko A. Cross-talk between insulin and IGF-1 receptors in the cortical collecting duct principal cells: implication for ENaC-mediated Na+ reabsorption. Am J Physiol Renal Physiol 2015; 308:F713-9. [PMID: 25651558 DOI: 10.1152/ajprenal.00081.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 01/20/2015] [Indexed: 12/17/2022] Open
Abstract
Insulin and IGF-1 are recognized as powerful regulators of the epithelial Na+ channel (ENaC) in the aldosterone-sensitive distal nephron. As previously described, these hormones both acutely increase ENaC activity in freshly isolated split open tubules and cultured principal cortical collecting duct cells. The present study was aimed at differentiating the effects of insulin and IGF-1 on Na+ transport in immortalized mpkCCDcl4 cells and defining their interrelations. We have shown that both insulin and IGF-1 applied basolaterally, but not apically, enhanced transepithelial Na+ transport in the mpkCCDcl4 cell line with EC50 values of 8.8 and 14.5 nM, respectively. Insulin treatment evoked phosphorylation of both insulin and IGF-1 receptors, whereas the effects of IGF-1 were more profound on its own receptor rather than the insulin receptor. AG-1024 and PPP, inhibitors of IGF-1 and insulin receptor tyrosine kinase activity, diminished insulin- and IGF-1-stimulated Na+ transport in mpkCCDcl4 cells. The effects of insulin and IGF-1 on ENaC-mediated currents were found to be additive, with insulin likely stimulating both IGF-1 and insulin receptors. We hypothesize that insulin activates IGF-1 receptors in addition to its own receptors, making the effects of these hormones interconnected.
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Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Michael W Brands
- Department of Physiology, Georgia Regents University, Augusta, Georgia
| | - Tengis S Pavlov
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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27
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Yiu WH, Lin M, Tang SCW. Toll-like receptor activation: from renal inflammation to fibrosis. Kidney Int Suppl (2011) 2014; 4:20-25. [PMID: 26312146 PMCID: PMC4536963 DOI: 10.1038/kisup.2014.5] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Toll-like receptors (TLRs) are a conserved family of pattern recognition receptors that play a fundamental role in the innate immune system by triggering proinflammatory signaling pathways in response to microbial pathogens through exogenous pathogen-associated molecular patterns or tissue injury through endogenous danger-associated molecular patterns. In the kidney, TLRs are widely expressed in a variety of cell types. Emerging evidence demonstrates the participation of TLRs in the activation of these cells during renal fibrosis. This review highlights the role of TLRs and their endogenous ligands in the pathogenesis of renal fibrosis using ureteral obstruction and diabetic nephropathy as models of chronic kidney disease.
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Affiliation(s)
- Wai Han Yiu
- Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong , Hong Kong
| | - Miao Lin
- Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong , Hong Kong
| | - Sydney C W Tang
- Division of Nephrology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong , Hong Kong
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28
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Zaika O, Mamenko M, Boukelmoune N, Pochynyuk O. IGF-1 and insulin exert opposite actions on ClC-K2 activity in the cortical collecting ducts. Am J Physiol Renal Physiol 2014; 308:F39-48. [PMID: 25339702 DOI: 10.1152/ajprenal.00545.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Despite similar stimulatory actions on the epithelial sodium channel (ENaC)-mediated sodium reabsorption in the distal tubule, insulin promotes kaliuresis, whereas insulin-like growth factor-1 (IGF-1) causes a reduction in urinary potassium levels. The factors contributing to this phenomenon remain elusive. Electrogenic distal nephron ENaC-mediated Na(+) transport establishes driving force for Cl(-) reabsorption and K(+) secretion. Using patch-clamp electrophysiology, we document that a Cl(-) channel is highly abundant on the basolateral plasma membrane of intercalated cells in freshly isolated mouse cortical collecting duct (CCD) cells. The channel has characteristics attributable to the ClC-K2: slow gating kinetics, conductance ∼10 pS, voltage independence, Cl(-)>NO3 (-) anion selectivity, and inhibition/activation by low/high pH, respectively. IGF-1 (100 and 500 nM) acutely stimulates ClC-K2 activity in a reversible manner. Inhibition of PI3-kinase (PI3-K) with LY294002 (20 μM) abrogates activation of ClC-K2 by IGF-1. Interestingly, insulin (100 nM) reversibly decreases ClC-K2 activity in CCD cells. This inhibitory action is independent of PI3-K and is mediated by stimulation of a mitogen-activated protein kinase-dependent cascade. We propose that IGF-1, by stimulating ClC-K2 channels, promotes net Na(+) and Cl(-) reabsorption, thus reducing driving force for potassium secretion by the CCD. In contrast, inhibition of ClC-K2 by insulin favors coupling of Na(+) reabsorption with K(+) secretion at the apical membrane contributing to kaliuresis.
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Affiliation(s)
- Oleg Zaika
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Mykola Mamenko
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Nabila Boukelmoune
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas
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29
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de Vries APJ, Ruggenenti P, Ruan XZ, Praga M, Cruzado JM, Bajema IM, D'Agati VD, Lamb HJ, Pongrac Barlovic D, Hojs R, Abbate M, Rodriquez R, Mogensen CE, Porrini E. Fatty kidney: emerging role of ectopic lipid in obesity-related renal disease. Lancet Diabetes Endocrinol 2014; 2:417-26. [PMID: 24795255 DOI: 10.1016/s2213-8587(14)70065-8] [Citation(s) in RCA: 320] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The global increase in chronic kidney disease (CKD) parallels the obesity epidemic. Obesity conveys a gradual but independent risk of progression of CKD that seems irrespective of the underlying nephropathy. Obesity has been associated with a secondary focal segmental glomerulosclerosis coined obesity-related glomerulopathy (ORG). Pathways through which obesity might cause renal disease are not well understood, and early clinical biomarkers for incipient ORG or renal relevant obesity are currently lacking. Recent human and experimental studies have associated ectopic lipid accumulation in the kidney (fatty kidney) with obesity-related renal disease. There is enough growing insight that ectopic lipid--the accumulation of lipid in non-adipose tissue--is associated with structural and functional changes of mesangial cells, podocytes, and proximal tubular cells to propose the development of ORG as a maladaptive response to hyperfiltration and albuminuria. Recent advances in metabolic imaging might validate ectopic lipid as a biomarker and research aid, to help translate novel therapeutics from experimental models to patients.
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Affiliation(s)
- Aiko P J de Vries
- Department of Nephrology, Leiden University Medical Center and Leiden University, Leiden, Netherlands.
| | - Piero Ruggenenti
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Ranica, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Xiong Z Ruan
- Moorhead Renal Research Laboratory, University College London, Royal Free Campus, London, UK; Centre for Nephrology and Urology, Shenzhen University Health Science Centre, Shenzhen, China
| | - Manuel Praga
- Departments of Nephrology and Medicine, Hospital 12 de Octubre, Complutense University, Madrid, Spain
| | - Josep M Cruzado
- Department of Nephrology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Ingeborg M Bajema
- Department of Pathology, Leiden University Medical Center and Leiden University, Leiden, Netherlands
| | - Vivette D D'Agati
- Department of Pathology, Columbia University Medical Center, New York, NY, USA
| | - Hildo J Lamb
- Department of Radiology, Leiden University Medical Center and Leiden University, Leiden, Netherlands
| | - Drazenka Pongrac Barlovic
- Department of Endocrinology, Diabetes and Metabolism, Ljubljana University Medical Center, Ljubljana, Slovenia
| | - Radovan Hojs
- Department of Nephrology, Clinic for Internal Medicine, University Clinical Centre and Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Manuela Abbate
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Ranica, Bergamo, Italy
| | - Rosa Rodriquez
- Department of Pathology, Hospital Universitario de Canarias, Tenerife
| | | | - Esteban Porrini
- Center for Biomedical Research of the Canary Islands (CIBICAN), University of La Laguna, Tenerife, Spain
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30
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Reiser J, Sever S, Faul C. Signal transduction in podocytes--spotlight on receptor tyrosine kinases. Nat Rev Nephrol 2014; 10:104-15. [PMID: 24394191 PMCID: PMC4109315 DOI: 10.1038/nrneph.2013.274] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mammalian kidney filtration barrier is a complex multicellular, multicomponent structure that maintains homeostasis by regulating electrolytes, acid-base balance, and blood pressure (via maintenance of salt and water balance). To perform these multiple functions, podocytes--an important component of the filtration apparatus--must process a series of intercellular signals. Integrating these signals with diverse cellular responses enables a coordinated response to various conditions. Although mature podocytes are terminally differentiated and cannot proliferate, they are able to respond to growth factors. It is possible that the initial response of podocytes to growth factors is beneficial and protective, and might include the induction of hypertrophic cell growth. However, extended and/or uncontrolled growth factor signalling might be maladaptive and could result in the induction of apoptosis and podocyte loss. Growth factors signal via the activation of receptor tyrosine kinases (RTKs) on their target cells and around a quarter of the 58 RTK family members that are encoded in the human genome have been identified in podocytes. Pharmacological inhibitors of many RTKs exist and are currently used in experimental and clinical cancer therapy. The identification of pathological RTK-mediated signal transduction pathways in podocytes could provide a starting point for the development of novel therapies for glomerular disorders.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, 1735 West Harrison Street, Cohn Building, Suite 724, Chicago, IL 60612, USA
| | - Sanja Sever
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA
| | - Christian Faul
- Division of Nephrology and Hypertension, University of Miami Miller School of Medicine, 1580 North West 10th Avenue (R-762), Batchelor Building 626, Miami, FL 33136, USA
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31
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Yamada E, Saito T, Okada S, Takahashi H, Ohshima K, Hashimoto K, Satoh T, Mori M, Okada J, Yamada M. Synip phosphorylation is required for insulin-stimulated Glut4 translocation and glucose uptake in podocyte. Endocr J 2014; 61:523-7. [PMID: 24705589 DOI: 10.1507/endocrj.ej14-0099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Previously we reported that the phosphorylation of Synip on serine 99 is required for Synip dissociation from Syntaxin4 and insulin-stimulated Glut4 translocation in cultured 3T3-L1 adipocytes. We also reported that the dissociated Synip remains anchored to the plasma membrane by binding to Phosphatidylinositol (3,4,5)-triphosphate. Recently Synip was reported to arrest SNARE-dependent membrane fusion as a selective t-SNARE binding inhibitor. In this study, we have found that Synip is expressed in podocytes although at a somewhat lower level than in adipocytes. To determine whether phosphorylation of Synip on serine 99 is required for insulin-stimulated Glut4 translocation and glucose uptake in podocytes we expressed a phosphorylation deficient Synip mutant (S99A-Synip) that inhibited insulin-stimulated Glut4 translocation and 2-deoxyglucose uptake in adipocytes. We conclude that serine 99 phosphorylation of Synip is required for Glut4 translocation and glucose uptake in both adipocytes and podocytes, suggesting that defects in Synip phosphorylation may underlie insulin resistance and associated diabetic nephropathy.
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Affiliation(s)
- Eijiro Yamada
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
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32
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Hao J, Zhu L, Li F, Liu Q, Zhao X, Liu S, Xing L, Feng X, Duan H. Phospho-mTOR: a novel target in regulation of renal lipid metabolism abnormality of diabetes. Exp Cell Res 2013; 319:2296-306. [PMID: 23827786 DOI: 10.1016/j.yexcr.2013.06.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/10/2013] [Accepted: 06/22/2013] [Indexed: 12/14/2022]
Abstract
The activation of Akt has been proved to involve in the lipogenesis of diabetic nephropathy. However, it's still not clear whether mTOR, another main gene in PI3K/Akt pathway, is also involved in the renal lipogenesis of diabetes. In the present study, it was revealed that the phosphorylation of mTOR was up-regulated in the renal tubular cells of diabetic rats, followed by the over-expression of SREBP-1, ADRP and lipogenesis. Again, high glucose increased the expression of phospho-mTOR accompanied with SREBP-1 and ADRP up-regulation and lipid accumulation in HKC cells. Rapamycin, known as mTOR inhibitor, was used to inhibit the activation of mTOR, which prevented effectively high glucose-induced SREBP-1 up-regulation and lipogenesis in HKC cells. Furthermore, high glucose-stimulated HKC cells transfected with wild-type mTOR vector showed the enhanced SREBP-1 and lipid droplets, however, TE mTOR vector (kinase dead)-transfected HKC cells presented resistance to high glucose and decreased SREBP-1 expression and lipogenesis. These above data suggested that phospho-mTOR mediated lipid accumulation in renal tubular cells of diabetes and might be the potential targets for treating lipogenesis of diabetic nephropathy.
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Affiliation(s)
- Jun Hao
- Department of Pathology, Hebei Medical University, Shijiazhuang 050017, China
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33
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Forbes JM, Harris DCH, Cooper ME. Report on ISN Forefronts, Melbourne, Australia, 4-7 October 2012: tubulointerstitial disease in diabetic nephropathy. Kidney Int 2013; 84:653-6. [PMID: 23698229 DOI: 10.1038/ki.2013.89] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 12/25/2012] [Accepted: 01/09/2013] [Indexed: 12/19/2022]
Abstract
The mechanisms involved in expansion of the tubulointerstitial compartment of the kidney in individuals with diabetes are not well understood. Given that tubulointerstitial damage is an important predictor of progression to end-stage kidney disease in most forms of chronic kidney disease it is imperative to gain a greater understanding of the processes involved. With this in mind, a very clear objective for the scientific content of this meeting was to spend more than half the program outside the comfort zone of nephrology, gaining insights from sources such as neurodegenerative and mitochondrial diseases, stem cells, cancer and high-level computing to reconstruct organ systems. The meeting also aimed to place the new concepts presented in the context of current knowledge in diabetic kidney disease and the milestones achieved to date in this area. The presenters were all extremely generous, giving not only their time, but also showing a large proportion of unpublished data to stimulate discussions, questions and innovation.
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Affiliation(s)
- Josephine M Forbes
- 1] Mater Medical Research Institute, South Brisbane, Queensland, Australia [2] Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
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