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Abstract
Chronic kidney disease (CKD) is a lethal and rapidly increasing burden on society. Despite this, there are relatively few therapies in development for the treatment of CKD. Several recent costly phase 3 trials have failed to provide improved renal outcomes, diminishing interest in pharmaceutical investment. Furthermore, poor patient, physician, and payer awareness of CKD as a diagnosis has contributed to slow trial enrollment and successful implementation of these trials. Nevertheless, several therapeutics remain in development for the treatment of CKD, including mineralocorticoid-receptor antagonists, sodium/glucose cotransporter 2 inhibitors, anti-inflammatory drugs, and drugs that mitigate oxidative injury. Success of future CKD therapeutic trials will depend not only on improved understanding of disease pathogenesis, but also on improved trial enrollment rates, through increasing awareness of this disease by the public, policy makers, and the greater medical community.
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Affiliation(s)
- Matthew D Breyer
- Biotechnology Discovery Research, Eli Lilly and Company, Indianapolis, IN.
| | - Katalin Susztak
- Renal Electrolyte and Hypertension Division, Department of Medicine, University of Pennsylvania, Philadelphia, PA
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202
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Idiopathic pre-capillary pulmonary hypertension in patients with end-stage kidney disease: effect of endothelin receptor antagonists. Clin Exp Nephrol 2016; 21:1088-1096. [PMID: 27757709 PMCID: PMC5698371 DOI: 10.1007/s10157-016-1344-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/06/2016] [Indexed: 11/16/2022]
Abstract
Background We examined the prevalence, prognosis, and effect of endothelin receptor antagonists on survival in end-stage kidney disease patients with idiopathic pre-capillary pulmonary hypertension. Methods We investigated 1988 end-stage kidney disease patients in Toujinkai Hospital from January 1, 2001 to December 31, 2014. Pulmonary hypertension was screened by symptoms (dyspnea, hypotension, or near syncope) and echocardiography, and diagnosed by computed tomography with enhancement, pulmonary flow scintigraphy, and right heart catheterization. Results Fifteen patients (67 ± 11 years; 12 women and 3 men) were diagnosed as idiopathic pre-capillary pulmonary hypertension; mean pulmonary arterial pressure, pulmonary vascular resistance, or pulmonary artery wedge pressure were 55 ± 11 mmHg, 7.5 ± 2.9 Woods units, or 12 ± 2 mmHg, respectively. Of the 15 patients, 14 received hemodialysis, and 1 was in a pre-dialysis stage. Patients were followed through December 31, 2015, and 11 died of heart failure; their mean survival time was 26.4 ± 21.0 months. Endothelin receptor antagonists were used for 11 patients, and mean survival times were 57.3 ± 12.1 months in patients with endothelin receptor antagonists and 7.5 ± 2.1 months in those without. In the Kaplan–Meier analysis, heart failure death-free survival rates were higher in patients with endothelin receptor antagonists than in those without (P < 0.001); 100 versus 25 % at one year and 71 versus 0 % at 3 years. Conclusion The prognosis of idiopathic pre-capillary pulmonary hypertension seems to be poor in end-stage kidney disease patients. Administration of endothelin receptor antagonists might improve the survival by inhibiting heart failure death. Registration of clinical trials This study was registered to the ClinicalTrials.gov (https://clinicaltrials.gov/): protocol identifier, NCT02743091.
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203
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Chan EAW, Buckley B, Farraj AK, Thompson LC. The heart as an extravascular target of endothelin-1 in particulate matter-induced cardiac dysfunction. Pharmacol Ther 2016; 165:63-78. [PMID: 27222357 PMCID: PMC6390286 DOI: 10.1016/j.pharmthera.2016.05.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Exposure to particulate matter air pollution has been causally linked to cardiovascular disease in humans. Several broad and overlapping hypotheses describing the biological mechanisms by which particulate matter exposure leads to cardiovascular disease have been explored, although linkage with specific factors or genes remains limited. These hypotheses may or may not also lead to particulate matter-induced cardiac dysfunction. Evidence pointing to autocrine/paracrine signaling systems as modulators of cardiac dysfunction has increased interest in the emerging role of endothelins as mediators of cardiac function following particulate matter exposure. Endothelin-1, a well-described small peptide expressed in the pulmonary and cardiovascular systems, is best known for its ability to constrict blood vessels, although it can also induce extravascular effects. Research on the role of endothelins in the context of air pollution has largely focused on vascular effects, with limited investigation of responses resulting from the direct effects of endothelins on cardiac tissue. This represents a significant knowledge gap in air pollution health effects research, given the abundance of endothelin receptors found on cardiac tissue and the ability of endothelin-1 to modulate cardiac contractility, heart rate, and rhythm. The plausibility of endothelin-1 as a mediator of particulate matter-induced cardiac dysfunction is further supported by the therapeutic utility of certain endothelin receptor antagonists. The present review examines the possibility that endothelin-1 release caused by exposure to PM directly modulates extravascular effects on the heart, deleteriously altering cardiac function.
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Affiliation(s)
- Elizabeth A W Chan
- Oak Ridge Institute for Science and Education (ORISE) Fellow at the National Center for Environmental Assessment, U.S. Environmental Protection Agency (EPA), Research Triangle Park, NC, USA
| | - Barbara Buckley
- National Center for Environmental Assessment, U.S. EPA, Research Triangle Park, NC, USA
| | - Aimen K Farraj
- Environmental Public Health Division, U.S. EPA, Research Triangle Park, NC, USA
| | - Leslie C Thompson
- Environmental Public Health Division, U.S. EPA, Research Triangle Park, NC, USA.
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204
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de Zeeuw D, Heerspink HJL. Unmet need in diabetic nephropathy: failed drugs or trials? Lancet Diabetes Endocrinol 2016; 4:638-640. [PMID: 27160545 DOI: 10.1016/s2213-8587(16)30045-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/09/2016] [Accepted: 04/11/2016] [Indexed: 11/19/2022]
Affiliation(s)
- Dick de Zeeuw
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, Netherlands.
| | - Hiddo J L Heerspink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, Netherlands
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205
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Seccia TM, Caroccia B, Gioco F, Piazza M, Buccella V, Guidolin D, Guerzoni E, Montini B, Petrelli L, Pagnin E, Ravarotto V, Belloni AS, Calò LA, Rossi GP. Endothelin-1 Drives Epithelial-Mesenchymal Transition in Hypertensive Nephroangiosclerosis. J Am Heart Assoc 2016; 5:JAHA.116.003888. [PMID: 27444511 PMCID: PMC5015413 DOI: 10.1161/jaha.116.003888] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Tubulointerstitial fibrosis, the final outcome of most kidney diseases, involves activation of epithelial mesenchymal transition (EMT). Endothelin-1 (ET-1) activates EMT in cancer cells, but it is not known whether it drives EMT in the kidney. We therefore tested the hypothesis that tubulointerstitial fibrosis involves EMT driven by ET-1. METHODS AND RESULTS Transgenic TG[mRen2]27 (TGRen2) rats developing fulminant angiotensin II-dependent hypertension with prominent cardiovascular and renal damage were submitted to drug treatments targeted to ET-1 and/or angiotensin II receptor or left untreated (controls). Expressional changes of E-cadherin and α-smooth muscle actin (αSMA) were examined as markers of renal EMT. In human kidney HK-2 proximal tubular cells expressing the ETB receptor subtype, the effects of ET-1 with or without ET-1 antagonists were also investigated. The occurrence of renal fibrosis was associated with EMT in control TGRen2 rats, as evidenced by decreased E-cadherin and increased αSMA expression. Irbesartan and the mixed ET-1 receptor antagonist bosentan prevented these changes in a blood pressure-independent fashion (P < 0.001 for both versus controls). In HK-2 cells ET-1 blunted E-cadherin expression, increased αSMA expression (both P < 0.01), collagen synthesis, and metalloproteinase activity (P < 0.005, all versus untreated cells). All changes were prevented by the selective ETB receptor antagonist BQ-788. Evidence for involvement of the Rho-kinase signaling pathway and dephosphorylation of Yes-associated protein in EMT was also found. CONCLUSIONS In angiotensin II-dependent hypertension, ET-1 acting via ETB receptors and the Rho-kinase and Yes-associated protein induces EMT and thereby renal fibrosis.
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Affiliation(s)
- Teresa M Seccia
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Brasilina Caroccia
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Francesca Gioco
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Maria Piazza
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Valentina Buccella
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Diego Guidolin
- Human Anatomy, Department of Molecular Medicine, University of Padua, Italy
| | - Eugenia Guerzoni
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
| | - Barbara Montini
- Immunology, Department of Medicine-DIMED, University of Padua, Italy
| | - Lucia Petrelli
- Human Anatomy, Department of Molecular Medicine, University of Padua, Italy
| | - Elisa Pagnin
- Nephrology Divisions, Department of Medicine-DIMED, University of Padua, Italy
| | - Verdiana Ravarotto
- Nephrology Divisions, Department of Medicine-DIMED, University of Padua, Italy
| | - Anna S Belloni
- Human Anatomy, Department of Molecular Medicine, University of Padua, Italy
| | - Lorenzo A Calò
- Nephrology Divisions, Department of Medicine-DIMED, University of Padua, Italy
| | - Gian Paolo Rossi
- Internal Medicine, Department of Medicine-DIMED, University of Padua, Italy
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206
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Pena-Polanco JE, Fried LF. Established and Emerging Strategies in the Treatment of Chronic Kidney Disease. Semin Nephrol 2016; 36:331-42. [DOI: 10.1016/j.semnephrol.2016.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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207
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Gallagher H, Suckling RJ. Diabetic nephropathy: where are we on the journey from pathophysiology to treatment? Diabetes Obes Metab 2016; 18:641-7. [PMID: 26743887 DOI: 10.1111/dom.12630] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/17/2015] [Accepted: 12/29/2015] [Indexed: 12/13/2022]
Abstract
Diabetic nephropathy affects 30-40% of people with diabetes, and is the leading cause of end-stage kidney disease. The current treatment paradigm relies on early detection, glycaemic control and tight blood pressure management with preferential use of renin-angiotensin system blockade. This strategy has transformed outcomes in diabetic kidney disease over the last 20 years. Over the last two decades we have also witnessed significant advances in the understanding of the pathophysiology of diabetic nephropathy; however, despite this new knowledge, we have yet to develop new treatments of proven efficacy. Whilst a continued emphasis on preclinical and clinical research is clearly needed, clinicians treating people with diabetes should not forget that, in the short term, the greatest gains are likely to be realised by more consistent deployment of existing therapies.
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Affiliation(s)
- H Gallagher
- SW Thames Renal Unit, St Helier Hospital, Carshalton, Surrey, UK
| | - R J Suckling
- SW Thames Renal Unit, St Helier Hospital, Carshalton, Surrey, UK
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208
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Abstract
Chronic kidney disease (CKD) represents a leading cause of death in the United States. There is no cure for this disease, with current treatment strategies relying on blood pressure control through blockade of the renin-angiotensin system. Such approaches only delay the development of end-stage kidney disease and can be associated with serious side effects. Recent identification of several novel mechanisms contributing to CKD development - including vascular changes, loss of podocytes and renal epithelial cells, matrix deposition, inflammation and metabolic dysregulation - has revealed new potential therapeutic approaches for CKD. This Review assesses emerging strategies and agents for CKD treatment, highlighting the associated challenges in their clinical development.
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209
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Komers R, Plotkin H. Dual inhibition of renin-angiotensin-aldosterone system and endothelin-1 in treatment of chronic kidney disease. Am J Physiol Regul Integr Comp Physiol 2016; 310:R877-84. [PMID: 27009050 PMCID: PMC4896079 DOI: 10.1152/ajpregu.00425.2015] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/11/2016] [Indexed: 12/19/2022]
Abstract
Inhibition of the renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in treatment of chronic kidney diseases (CKD). However, reversal of the course of CKD or at least long-term stabilization of renal function are often difficult to achieve, and many patients still progress to end-stage renal disease. New treatments are needed to enhance protective actions of RAAS inhibitors (RAASis), such as angiotensin-converting enzyme (ACE) inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), and improve prognosis in CKD patients. Inhibition of endothelin (ET) system in combination with established RAASis may represent such an approach. There are complex interactions between both systems and similarities in their renal physiological and pathophysiological actions that provide theoretical rationale for combined inhibition. This view is supported by some experimental studies in models of both diabetic and nondiabetic CKD showing that a combination of RAASis with ET receptor antagonists (ERAs) ameliorate proteinuria, renal structural changes, and molecular markers of glomerulosclerosis, renal fibrosis, or inflammation more effectively than RAASis or ERAs alone. Practically all clinical studies exploring the effects of RAASis and ERAs combination in nephroprotection have thus far applied add-on designs, in which an ERA is added to baseline treatment with ACEIs or ARBs. These studies, conducted mostly in patients with diabetic nephropathy, have shown that ERAs effectively reduce residual proteinuria in patients with baseline RAASis treatment. Long-term studies are currently being conducted to determine whether promising antiproteinuric effects of the dual blockade will be translated in long-term nephroprotection with acceptable safety profile.
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210
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Scheele W, Diamond S, Gale J, Clerin V, Tamimi N, Le V, Walley R, Grover-Páez F, Perros-Huguet C, Rolph T, El Nahas M. Phosphodiesterase Type 5 Inhibition Reduces Albuminuria in Subjects with Overt Diabetic Nephropathy. J Am Soc Nephrol 2016; 27:3459-3468. [PMID: 27113485 DOI: 10.1681/asn.2015050473] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 02/23/2016] [Indexed: 12/31/2022] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of ESRD worldwide. Reduced bioavailability or uncoupling of nitric oxide in the kidney, leading to decreased intracellular levels of the nitric oxide pathway effector molecule cyclic guanosine monophosphate (cGMP), has been implicated in the progression of DN. Preclinical studies suggest that elevating the cGMP intracellular pool through inhibition of the cGMP-hydrolyzing enzyme phosphodiesterase type 5 (PDE5) might exert renoprotective effects in DN. To test this hypothesis, the novel, highly specific, and long-acting PDE5 inhibitor, PF-00489791, was assessed in a multinational, multicenter, randomized, double-blind, placebo-controlled, parallel group trial of subjects with type 2 diabetes mellitus and overt nephropathy receiving angiotensin converting enzyme inhibitor or angiotensin receptor blocker background therapy. In total, 256 subjects with an eGFR between 25 and 60 ml/min per 1.73 m2 and macroalbuminuria defined by a urinary albumin-to-creatinine ratio >300 mg/g, were randomly assigned 3:1, respectively, to receive PF-00489791 (20 mg) or placebo orally, once daily for 12 weeks. Using the predefined primary assessment of efficacy (Bayesian analysis with informative prior), we observed a significant reduction in urinary albumin-to-creatinine ratio of 15.7% (ratio 0.843; 95% credible interval 0.73 to 0.98) in response to the 12-week treatment with PF-00489791 compared with placebo. PF-00489791 was safe and generally well tolerated in this patient population. Most common adverse events were mild in severity and included headache and upper gastrointestinal events. In conclusion, the safety and efficacy profile of PDE5 inhibitor PF-00489791 supports further investigation as a novel therapy to improve renal outcomes in DN.
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Affiliation(s)
| | - Susan Diamond
- San Antonio Kidney Disease Center, San Antonio, Texas
| | | | | | | | - Vu Le
- Pfizer Inc., Cambridge, Massachusetts
| | | | - Fernando Grover-Páez
- Institute of Experimental and Clinical Therapeutics, Universidad de Guadalajara, Guadalajara, México; and
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211
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Yuan W, Li Y, Wang J, Li J, Gou S, Fu P. Endothelin-receptor antagonists for diabetic nephropathy: A meta-analysis. Nephrology (Carlton) 2016; 20:459-66. [PMID: 25753148 DOI: 10.1111/nep.12442] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2015] [Indexed: 02/05/2023]
Abstract
AIM Endothelin-receptor antagonists may be a novel therapeutic strategy for diabetic nephropathy, but their use remains controversial. This meta-analysis seeks to evaluate the effectiveness and safety of endothelin-receptor antagonists for patients with diabetic nephropathy. METHODS Literature reviews of the PubMed, EMBASE and CENTRAL databases were conducted to identify randomized controlled trials (RCTs) comparing endothelin-receptor antagonist treatment with placebo in patients with diabetic nephropathy. Quality assessment was performed by using the Cochrane Handbook's tools for assessing risk of bias; meta-analysis was conducted by RevMan 5.3. RESUTLS Five RCTs (n=2034 patients) were included for analysis. Compared with placebo, endothelin-receptor antagonists showed significant benefits for lowering albuminuria (five trials, n=2034 patients; SMD 0.66 95% confidence interval (CI) 0.56 to 0.76), but there was no significant difference in the risk of death (two trials, n=1674 patients; RR 1.49 95% CI 0.81 to 2.76). In addition, risk of cardiovascular events and other serious adverse events were significantly higher in the endothelin-receptor antagonists group than the placebo group (four trials, n=1956 patients; RR 1.45 95% CI 1.07 to 1.97; five trials, n=2034 patients; RR 1.32 95% CI 1.10 to 1.58). CONCLUSION Endothelin-receptor antagonists can reduce albuminuria in patients with diabetic nephropathy, although use resulted in more serious adverse events compared with placebo. There is a potential need for further RCTs, which has larger sample size and longer duration.
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Affiliation(s)
- Wenming Yuan
- Renal Division, Department of Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Yi Li
- Kidney Epidemiology and Cost Center, University of Michigan, Ann Arbor, MI, USA
| | - Ji Wang
- Division of Evidence-Based Medicine and Clinical Epidemiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Jing Li
- Division of Evidence-Based Medicine and Clinical Epidemiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Shenju Gou
- Renal Division, Department of Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Ping Fu
- Renal Division, Department of Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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212
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Davenport AP, Hyndman KA, Dhaun N, Southan C, Kohan DE, Pollock JS, Pollock DM, Webb DJ, Maguire JJ. Endothelin. Pharmacol Rev 2016; 68:357-418. [PMID: 26956245 PMCID: PMC4815360 DOI: 10.1124/pr.115.011833] [Citation(s) in RCA: 488] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The endothelins comprise three structurally similar 21-amino acid peptides. Endothelin-1 and -2 activate two G-protein coupled receptors, ETA and ETB, with equal affinity, whereas endothelin-3 has a lower affinity for the ETA subtype. Genes encoding the peptides are present only among vertebrates. The ligand-receptor signaling pathway is a vertebrate innovation and may reflect the evolution of endothelin-1 as the most potent vasoconstrictor in the human cardiovascular system with remarkably long lasting action. Highly selective peptide ETA and ETB antagonists and ETB agonists together with radiolabeled analogs have accurately delineated endothelin pharmacology in humans and animal models, although surprisingly no ETA agonist has been discovered. ET antagonists (bosentan, ambrisentan) have revolutionized the treatment of pulmonary arterial hypertension, with the next generation of antagonists exhibiting improved efficacy (macitentan). Clinical trials continue to explore new applications, particularly in renal failure and for reducing proteinuria in diabetic nephropathy. Translational studies suggest a potential benefit of ETB agonists in chemotherapy and neuroprotection. However, demonstrating clinical efficacy of combined inhibitors of the endothelin converting enzyme and neutral endopeptidase has proved elusive. Over 28 genetic modifications have been made to the ET system in mice through global or cell-specific knockouts, knock ins, or alterations in gene expression of endothelin ligands or their target receptors. These studies have identified key roles for the endothelin isoforms and new therapeutic targets in development, fluid-electrolyte homeostasis, and cardiovascular and neuronal function. For the future, novel pharmacological strategies are emerging via small molecule epigenetic modulators, biologicals such as ETB monoclonal antibodies and the potential of signaling pathway biased agonists and antagonists.
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Affiliation(s)
- Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Kelly A Hyndman
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Neeraj Dhaun
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Christopher Southan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Donald E Kohan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Jennifer S Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David M Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David J Webb
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
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Wischnjow A, Sarko D, Janzer M, Kaufman C, Beijer B, Brings S, Haberkorn U, Larbig G, Kübelbeck A, Mier W. Renal Targeting: Peptide-Based Drug Delivery to Proximal Tubule Cells. Bioconjug Chem 2016; 27:1050-7. [DOI: 10.1021/acs.bioconjchem.6b00057] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Artjom Wischnjow
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Dikran Sarko
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Maria Janzer
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
- Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany
| | - Christina Kaufman
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Barbro Beijer
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Sebastian Brings
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Uwe Haberkorn
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
| | - Gregor Larbig
- Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany
| | - Armin Kübelbeck
- Merck KGaA, Frankfurter Strasse 250, 64293 Darmstadt, Germany
| | - Walter Mier
- Department of Nuclear Medicine, Heidelberg University Hospital, INF 400, 69120 Heidelberg, Germany
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214
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Garsen M, Lenoir O, Rops ALWMM, Dijkman HB, Willemsen B, van Kuppevelt TH, Rabelink TJ, Berden JHM, Tharaux PL, van der Vlag J. Endothelin-1 Induces Proteinuria by Heparanase-Mediated Disruption of the Glomerular Glycocalyx. J Am Soc Nephrol 2016; 27:3545-3551. [PMID: 27026367 DOI: 10.1681/asn.2015091070] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 02/22/2016] [Indexed: 12/12/2022] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of CKD in the Western world. Endothelin receptor antagonists have emerged as a novel treatment for DN, but the mechanisms underlying the protective effect remain unknown. We previously showed that both heparanase and endothelin-1 are essential for the development of DN. Here, we further investigated the role of these proteins in DN, and demonstrated that endothelin-1 activates podocytes to release heparanase. Furthermore, conditioned podocyte culture medium increased glomerular transendothelial albumin passage in a heparanase-dependent manner. In mice, podocyte-specific knockout of the endothelin receptor prevented the diabetes-induced increase in glomerular heparanase expression, consequent reduction in heparan sulfate expression and endothelial glycocalyx thickness, and development of proteinuria observed in wild-type counterparts. Our data suggest that in diabetes, endothelin-1 signaling, as occurs in endothelial activation, induces heparanase expression in the podocyte, damage to the glycocalyx, proteinuria, and renal failure. Thus, prevention of these effects may constitute the mechanism of action of endothelin receptor blockers in DN.
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Affiliation(s)
| | - Olivia Lenoir
- Paris Cardiovascular Research Centre, Institut de la Santé et de la Recherche Médicale, Paris, France; and
| | | | | | | | | | - Ton J Rabelink
- Department of Nephrology, Einthoven Laboratory for Vascular Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Pierre-Louis Tharaux
- Paris Cardiovascular Research Centre, Institut de la Santé et de la Recherche Médicale, Paris, France; and
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215
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Lambers Heerspink HJ, Oberbauer R, Perco P, Heinzel A, Heinze G, Mayer G, Mayer B. Drugs meeting the molecular basis of diabetic kidney disease: bridging from molecular mechanism to personalized medicine. Nephrol Dial Transplant 2016. [PMID: 26209732 DOI: 10.1093/ndt/gfv210] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diabetic kidney disease (DKD) is a complex, multifactorial disease and is associated with a high risk of renal and cardiovascular morbidity and mortality. Clinical practice guidelines for diabetes recommend essentially identical treatments for all patients without taking into account how the individual responds to the instituted therapy. Yet, individuals vary widely in how they respond to medications and therefore optimal therapy differs between individuals. Understanding the underlying molecular mechanisms of variability in drug response will help tailor optimal therapy. Polymorphisms in genes related to drug pharmacokinetics have been used to explore mechanisms of response variability in DKD, but with limited success. The complex interaction between genetic make-up and environmental factors on the abundance of proteins and metabolites renders pharmacogenomics alone insufficient to fully capture response variability. A complementary approach is to attribute drug response variability to individual variability in underlying molecular mechanisms involved in the progression of disease. The interplay of different processes (e.g. inflammation, fibrosis, angiogenesis, oxidative stress) appears to drive disease progression, but the individual contribution of each process varies. Drugs at the other hand address specific targets and thereby interfere in certain disease-associated processes. At this level, biomarkers may help to gain insight into which specific pathophysiological processes are involved in an individual followed by a rational assessment whether a specific drug's mode of action indeed targets the relevant process at hand. This article describes the conceptual background and data-driven workflow developed by the SysKid consortium aimed at improving characterization of the molecular mechanisms underlying DKD at the interference of the molecular impact of individual drugs in order to tailor optimal therapy to individual patients.
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Affiliation(s)
- Hiddo J Lambers Heerspink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rainer Oberbauer
- Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Paul Perco
- Emergentec biodevelopment GmbH, Vienna, Austria
| | | | - Georg Heinze
- Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Gert Mayer
- Department of Internal Medicine IV, Medical University of Innsbruck, Innsbruck, Austria
| | - Bernd Mayer
- Emergentec biodevelopment GmbH, Vienna, Austria
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216
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Czopek A, Moorhouse R, Webb DJ, Dhaun N. Therapeutic potential of endothelin receptor antagonism in kidney disease. Am J Physiol Regul Integr Comp Physiol 2016; 310:R388-97. [DOI: 10.1152/ajpregu.00478.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/20/2015] [Indexed: 11/22/2022]
Abstract
Our growing understanding of the role of the endothelin (ET) system in renal physiology and pathophysiology is from emerging studies of renal disease in animal models and humans. ET receptor antagonists reduce blood pressure and proteinuria in chronic kidney disease and cause regression of renal injury in animals. However, the therapeutic potential of ET receptor antagonism has not been fully explored and clinical studies have been largely limited to patients with diabetic nephropathy. There remains a need for more work in nondiabetic chronic kidney disease, end-stage renal disease (patients requiring maintenance dialysis and those with a functioning kidney transplant), ischemia reperfusion injury, and sickle cell disease. The current review summarizes the most recent advances in both preclinical and clinical studies of ET receptor antagonists in the field of kidney disease.
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Affiliation(s)
- Alicja Czopek
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - Rebecca Moorhouse
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - David J. Webb
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
| | - Neeraj Dhaun
- University/British Heart Foundation Centre of Research Excellence, University of Edinburgh; and The Queen's Medical Research Institute, Edinburgh; and
- Department of Renal Medicine, Royal Infirmary of Edinburgh, United Kingdom
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217
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Chan GC, Tang SC. Diabetic nephropathy: landmark clinical trials and tribulations. Nephrol Dial Transplant 2016; 31:359-368. [DOI: 10.1093/ndt/gfu411] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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218
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Liu JY, Chen XX, Tang SCW, Sze SCW, Feng YB, Lee KF, Zhang KYB. Chinese medicines in the treatment of experimental diabetic nephropathy. Chin Med 2016; 11:6. [PMID: 26913057 PMCID: PMC4765093 DOI: 10.1186/s13020-016-0075-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 01/26/2016] [Indexed: 12/22/2022] Open
Abstract
Diabetic nephropathy (DN) is a severe micro vascular complication accompanying diabetes mellitus that affects millions of people worldwide. End-stage renal disease occurs in nearly half of all DN patients, resulting in large medical costs and lost productivity. The course of DN progression is complicated, and effective and safe therapeutic strategies are desired. While the complex nature of DN renders medicines with a single therapeutic target less efficacious, Chinese medicine, with its holistic view targeting the whole system of the patient, has exhibited efficacy for DN management. This review aims to describe the experimental evidence for Chinese medicines in DN management, with an emphasis on the underlying mechanisms, and to discuss the combined use of herbs and drugs in DN treatment.
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Affiliation(s)
- Jing-Yi Liu
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Xiao-Xin Chen
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Sydney Chi-Wai Tang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Stephen Cho-Wing Sze
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Yi-Bin Feng
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Kai-Fai Lee
- Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
| | - Kalin Yan-Bo Zhang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 10 Sassoon Road, Hong Kong, People's Republic of China
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219
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Abstract
The incidence of progressive kidney disease associated with diabetes continues to increase worldwide. Only partial renoprotection is achieved by current standard therapy with angiotensin-converting enzyme inhibitors and/or angiotensin-receptor blockers, increasing the need for novel therapeutic approaches. Experimental studies have provided evidence of a pathogenic role for endothelin-1 (ET-1) and its cognate receptors in the development and progression of diabetic nephropathy. ET-1, mainly through the activation of ETA receptor, contributes to renal cell injury, inflammation, and fibrosis. In animal models of type 1 and type 2 diabetes, ETA-selective antagonists have been shown to provide renoprotective effects, supplying the rationale for clinical trials in patients with diabetic nephropathy with ETA-receptor antagonists administered in addition to renin-angiotensin system blockade.
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Affiliation(s)
- Elena Gagliardini
- Unit of Advanced Microscopy, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- Laboratory of Pathophysiology of Experimental Renal Disease and Interaction With Other Organ Systems, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ariela Benigni
- Department of Molecular Medicine, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.
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220
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Vaněčková I, Řezáčová L, Kuneš J, Zicha J. Moderate additive effects of endothelin receptor A blockade in Ren-2 transgenic rats subjected to various types of RAS blockade. Life Sci 2016; 159:127-134. [PMID: 26775568 DOI: 10.1016/j.lfs.2016.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/11/2016] [Accepted: 01/12/2016] [Indexed: 11/19/2022]
Abstract
AIMS Chronic endothelin receptor A (ETA) blockade lowered blood pressure (BP) by decreasing angiotensin-dependent vasoconstriction and attenuating calcium influx. We tested whether the addition of ETA blockade to renin-angiotensin system (RAS) blockade would have further effects on the principal vasoactive systems contributing to BP maintenance in Ren-2 transgenic rats (TGR). METHODS Four-week-old TGR rats were fed with normal-salt diet and given either different renin-angiotensin system (RAS) blockers [angiotensin receptor blocker losartan, angiotensin converting enzyme inhibitor captopril, direct renin inhibitor aliskiren], or ETA blocker (atrasentan) alone, or a combination of atrasentan with RAS blockers for 4weeks. At the end of the study, basal BP and acute BP responses to sequential blockade of renin-angiotensin (RAS), sympathetic nervous (SNS), and nitric oxide (NO) systems were determined in conscious rats. Thereafter, BP responses to acute inhibition of nifedipine-sensitive calcium influx through voltage-dependent calcium channels (L-VDCC) were measured. KEY FINDINGS All RAS blockers similarly decreased BP to normotension, their effects being mediated through substantially attenuated RAS-dependent and moderately decreased SNS-dependent vasoconstriction. Atrasentan alone partially lowered BP, while BP was normalized by combination of atrasentan with either RAS blocker. In combination therapies, BP lowering effects resulted from the attenuation of both RAS- and SNS-dependent vasoconstriction. Moreover, atrasentan-treated groups had substantially reduced NO-dependent vasodilation and significantly decreased calcium influx through L-VDCC. CONCLUSIONS Although the BP-lowering effect of combined ETA and RAS blockades in TGR is predominantly dependent on the effects exerted by RAS blockade, further effects are attributable to decreased calcium influx due to chronic ETA blockade.
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Affiliation(s)
| | | | | | - Josef Zicha
- Institute of Physiology AS CR, Prague, Czech Republic
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221
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Abstract
Diabetic nephropathy is rapidly becoming the major cause of end-stage renal disease and cardiovascular mortality worldwide. Standard of care therapies include strict glycemic control and blockade of the renin-angiotensin-aldosterone axis. While these treatments slow progression of diabetic nephropathy, they do not arrest or reverse it. Newer therapies targeting multiple molecular pathways involved in renal inflammation, fibrosis, and oxidative stress have shown promise in animal models. Subsequently, many of these agents have been investigated in clinical human trials with mixed results. In this review, we will discuss recent findings of novel agents used in the treatment of diabetic nephropathy.
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Affiliation(s)
- Sadaf S Khan
- Division of Nephrology and Hypertension, Feinberg School of Medicine, Northwestern University, 303 East Superior Lurie Building, 10th Floor, Chicago, IL, 60611, USA.
| | - Susan E Quaggin
- Division of Nephrology and Hypertension, Feinberg School of Medicine, Northwestern University, 303 East Superior Lurie Building, 10th Floor, Chicago, IL, 60611, USA
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222
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Abstract
Chronic kidney disease (CKD) is associated with significant morbidity and mortality, impacted not alone by progression to end-stage kidney disease, but also by the high associated incidence of cardiovascular events and related mortality. Despite our current understanding of the pathogenesis of CKD and the treatments available, the reported incidence of CKD continues to rise worldwide, and is often referred to as the silent public healthcare epidemic. The significant cost to patient wellbeing and to the economy of managing the later stages of CKD have prompted efforts to develop interventions to delay the development and progression of this syndrome. In this article, we review established and novel agents that may aid in delaying the progression of CKD and improve patient outcomes.
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Affiliation(s)
- Frank Ward
- St Vincent's University Hospital, Dublin 4, Ireland
| | - John Holian
- St Vincent's University Hospital, Dublin 4, Ireland
| | - Patrick T Murray
- School of Medicine, University College Dublin, Health Sciences Centre, Dublin 4, Ireland
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223
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Pandit MM, Gao Y, van Hoek A, Kohan DE. Osmolar regulation of endothelin-1 production by the inner medullary collecting duct. Life Sci 2015; 159:135-139. [PMID: 26546722 DOI: 10.1016/j.lfs.2015.10.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/16/2015] [Accepted: 10/31/2015] [Indexed: 02/01/2023]
Abstract
AIMS Endothelin-1 (ET-1) is an autocrine inhibitor of collecting duct (CD) Na(+) and water reabsorption. CD ET-1 production is increased by a high salt diet and is important in promoting a natriuretic response. The mechanisms by which a high salt diet enhances CD ET-1 are being uncovered. In particular, elevated tubule fluid flow, as occurs in salt loading, enhances CD ET-1 synthesis. Tubule fluid solute content and interstitial osmolality can also be altered by a high salt diet, however their effect on CD ET-1 alone, or in combination with flow, is poorly understood. MAIN METHODS ET-1 mRNA production by a mouse inner medullary CD cell line (mIMCD3) in response to changing flow and/or osmolality was assessed. KEY FINDINGS Flow or hyperosmolality (using NaCl, mannitol or urea) individually caused an ~2-fold increase in ET-1 mRNA, while flow and hyperosmolality together increased ET-1 mRNA by ~14 fold. The hyperosmolality effect alone and the synergistic effect of flow + hyperosmolality was inhibited by chelation of intracellular Ca(2+), however were not altered by blockade of downstream Ca(2+)-signaling pathways (calcineurin or NFATc), inhibition of cellular Ca(2+) entry channels (purinergic receptors or polycystin-2), or blockade of the epithelial Na(+) channel. Inhibition of NFAT5 with rottlerin or NFAT5 siRNA greatly reduced the stimulatory effect of osmolality alone and osmolality + flow on mIMCD3 ET-1 mRNA levels. SIGNIFICANCE Both flow and osmolality individually and synergistically stimulate mIMCD3 ET-1 mRNA content. These findings may be relevant to explaining high salt diet induction of CD ET-1 production.
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Affiliation(s)
- Meghana M Pandit
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT, USA; Department of Pharmaceutics and Pharmaceutical Chemistry, Salt Lake City, UT, USA
| | - Yang Gao
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Alfred van Hoek
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, UT, USA; Department of Pharmaceutics and Pharmaceutical Chemistry, Salt Lake City, UT, USA; Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USA.
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224
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Surrogate endpoints in clinical trials of chronic kidney disease progression. Curr Opin Nephrol Hypertens 2015; 24:492-7. [DOI: 10.1097/mnh.0000000000000159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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225
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Johnson SA, Spurney RF. Twenty years after ACEIs and ARBs: emerging treatment strategies for diabetic nephropathy. Am J Physiol Renal Physiol 2015; 309:F807-20. [PMID: 26336162 DOI: 10.1152/ajprenal.00266.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/01/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetic nephropathy (DN) is a serious complication of both type 1 and type 2 diabetes mellitus. The disease is now the most common cause of end-stage kidney disease (ESKD) in developed countries, and both the incidence and prevalence of diabetes mellitus is increasing worldwide. Current treatments are directed at controlling hyperglycemia and hypertension, as well as blockade of the renin angiotensin system with angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin receptor blockers. Despite these therapies, DN progresses to ESKD in many patients. As a result, much interest is focused on developing new therapies. It has been over two decades since ACEIs were shown to have beneficial effects in DN independent of their blood pressure-lowering actions. Since that time, our understanding of disease mechanisms in DN has evolved. In this review, we summarize major cell signaling pathways implicated in the pathogenesis of diabetic kidney disease, as well as emerging treatment strategies. The goal is to identify promising targets that might be translated into therapies for the treatment of patients with diabetic kidney disease.
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Affiliation(s)
- Stacy A Johnson
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina
| | - Robert F Spurney
- Division of Nephrology, Department of Medicine, Duke University and Durham VA Medical Centers, Durham, North Carolina
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226
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Sodium-glucose cotransporter-2 inhibition and the potential for renal protection in diabetic nephropathy. Curr Opin Nephrol Hypertens 2015; 24:96-103. [PMID: 25470017 DOI: 10.1097/mnh.0000000000000084] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW Renal hyperfiltration has been used as a surrogate marker for increased intraglomerular pressure in patients with diabetes mellitus. Previous human investigation examining the pathogenesis of hyperfiltration has focused on the role of neurohormones such as the renin-angiotensin-aldosterone system (RAAS). Unfortunately, RAAS blockade does not completely attenuate hyperfiltration or diabetic kidney injury. More recent work has therefore investigated the contribution of renal tubular factors, including the sodium-glucose cotransporter, to the hyperfiltration state, which is the topic of this review. RECENT FINDINGS Novel sodium-glucose cotransporter-2 (SGLT2) inhibitors reduce proximal tubular sodium reabsorption, thereby increasing distal sodium delivery to the macula densa, causing tubuloglomerular feedback, afferent vasoconstriction and decreased hyperfiltration in animals. In humans, SGLT2 inhibition was recently shown to reduce hyperfiltration in normotensive, normoalbuminuric patients with type 1 diabetes. In clinical trials of type 2 diabetes, SGLT2 is associated with significant renal effects, including modest, acute declines in estimated glomerular filtration rate followed by the maintenance of stable renal function, and reduced albuminuria. SUMMARY Existing data are supportive of a potential renal-protective role for SGLT2 inhibition in patients with diabetes. Dedicated renal outcome trials are ongoing and have the potential to change the clinical practice.
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227
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Abstract
IN BRIEF Hypertension is prevalent in most individuals with diabetic kidney disease (DKD). Failure to treat hypertension appropriately in this subgroup of patients results in an increased risk of cardiovascular morbidity and mortality, as well as a faster progression of kidney disease. The current guidance for appropriate treatment of hypertension in this high-risk population provides an opportunity to improve both kidney and cardiovascular outcomes. This review discusses the current state of evidence-based hypertension management in patients with DKD.
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Affiliation(s)
- Vikram Patney
- University of Missouri Columbia School of Medicine, Department of Medicine, Division of Nephrology and Hypertension, Columbia, MO
| | - Adam Whaley-Connell
- University of Missouri Columbia School of Medicine, Department of Medicine, Division of Nephrology and Hypertension, Columbia, MO
- Research Service, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO
| | - George Bakris
- The University of Chicago Medicine, ASH Comprehensive Hypertension Center, Chicago, IL
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228
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Schievink B, de Zeeuw D, Smink PA, Andress D, Brennan JJ, Coll B, Correa-Rotter R, Hou FF, Kohan D, Kitzman DW, Makino H, Parving HH, Perkovic V, Remuzzi G, Tobe S, Toto R, Hoekman J, Lambers Heerspink HJ. Prediction of the effect of atrasentan on renal and heart failure outcomes based on short-term changes in multiple risk markers. Eur J Prev Cardiol 2015; 23:758-68. [PMID: 26229089 DOI: 10.1177/2047487315598709] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/13/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND A recent phase II clinical trial (Reducing Residual Albuminuria in Subjects with Diabetes and Nephropathy with AtRasentan trial and an identical trial in Japan (RADAR/JAPAN)) showed that the endothelin A receptor antagonist atrasentan lowers albuminuria, blood pressure, cholesterol, hemoglobin, and increases body weight in patients with type 2 diabetes and nephropathy. We previously developed an algorithm, the Parameter Response Efficacy (PRE) score, which translates short-term drug effects into predictions of long-term effects on clinical outcomes. DESIGN We used the PRE score on data from the RADAR/JAPAN study to predict the effect of atrasentan on renal and heart failure outcomes. METHODS We performed a post-hoc analysis of the RADAR/JAPAN randomized clinical trials in which 211 patients with type-2 diabetes and nephropathy were randomly assigned to atrasentan 0.75 mg/day, 1.25 mg/day, or placebo. A PRE score was developed in a background set of completed clinical trials using multivariate Cox models. The score was applied to baseline and week-12 risk marker levels of RADAR/JAPAN participants, to predict atrasentan effects on clinical outcomes. Outcomes were defined as doubling serum creatinine or end-stage renal disease and hospitalization for heart failure. RESULTS The PRE score predicted renal risk changes of -23% and -30% for atrasentan 0.75 and 1.25 mg/day, respectively. PRE scores also predicted a small non-significant increase in heart failure risk for atrasentan 0.75 and 1.25 mg/day (+2% vs. +7%). Selecting patients with >30% albuminuria reduction from baseline (responders) improved renal outcome to almost 50% risk reduction, whereas non-responders showed no renal benefit. CONCLUSIONS Based on the RADAR/JAPAN study, with short-term changes in risk markers, atrasentan is expected to decrease renal risk without increased risk of heart failure. Within this population albuminuria responders appear to contribute to the predicted improvements, whereas non-responders showed no benefit. The ongoing hard outcome trial (SONAR) in type 2 diabetic patients with >30% albuminuria reduction to atrasentan will allow us to assess the validity of these predictions.
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Affiliation(s)
- Bauke Schievink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Dick de Zeeuw
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Paul A Smink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | | | | | - Blai Coll
- Renal Clinical Development, Abbvie, North Chicago, USA
| | - Ricardo Correa-Rotter
- National Medical Science and Nutrition Institute Salvador Zubiran, Mexico City, Mexico
| | - Fan Fan Hou
- Renal Division, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Donald Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, USA
| | - Dalane W Kitzman
- Cardiology Section, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, USA
| | | | - Hans-Henrik Parving
- Department of Medical Endocrinology Rigshospitalet, University Hospital of Copenhagen, Denmark
| | - Vlado Perkovic
- The George Institute for International Health, The University of Sydney, Australia
| | - Giuseppe Remuzzi
- IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Bergamo, Italy; Unit of Nephrology, Dialysis and Transplantation, AO Papa Giovanni XXIII, Bergamo, Italy
| | - Sheldon Tobe
- Sunnybrook Health Sciences Center, Toronto, Canada
| | - Robert Toto
- University of Texas Southwestern Medical Center, Dallas, USA
| | - Jarno Hoekman
- Utrecht Institute for Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, The Netherlands
| | - Hiddo J Lambers Heerspink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
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229
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Kohan DE, Lambers Heerspink HJ, Coll B, Andress D, Brennan JJ, Kitzman DW, Correa-Rotter R, Makino H, Perkovic V, Hou FF, Remuzzi G, Tobe SW, Toto R, Parving HH, de Zeeuw D. Predictors of Atrasentan-Associated Fluid Retention and Change in Albuminuria in Patients with Diabetic Nephropathy. Clin J Am Soc Nephrol 2015; 10:1568-74. [PMID: 26153128 DOI: 10.2215/cjn.00570115] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/22/2015] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Endothelin A receptor antagonists (ERAs) decrease residual albuminuria in patients with diabetic kidney disease; however, their clinical utility may be limited by fluid retention. Consequently, the primary objective of this study was to identify predictors for ERA-induced fluid retention among patients with type 2 diabetes and CKD. A secondary objective was to determine if the degree of fluid retention necessarily correlated with the magnitude of albuminuria reduction in those patients receiving ERAs. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A post hoc analysis was conducted of the phase IIb atrasentan trials assessing albuminuria reduction in 211 patients with type 2 diabetes, urine albumin/creatinine ratios of 300-3500 mg/g, and eGFRs of 30-75 ml/min per 1.73 m(2) who were randomly assigned to receive placebo (n=50) or atrasentan 0.75 mg/d (n=78) or 1.25 mg/d (n=83) for 12 weeks. Changes in body weight and hemoglobin (Hb) after 2 weeks of treatment were used as surrogate markers of fluid retention. RESULTS Baseline predictors of weight gain after 2 weeks of atrasentan treatment were higher atrasentan dose, lower eGFR, higher glycated hemoglobin, higher systolic BP, and lower homeostatic metabolic assessment product. Higher atrasentan dose and lower eGFR also predicted decreases in Hb. There were no changes in B-type natriuretic peptide. There was no correlation between reduction in albuminuria after 2 weeks of atrasentan treatment and changes in body weight or Hb. CONCLUSIONS In the Reducing Residual Albuminuria in Subjects With Diabetes and Nephropathy With Atrasentan/JAPAN trials, atrasentan-associated fluid retention was more likely in patients with diabetes and nephropathy who had lower eGFR or received a higher dose of atrasentan. Finding that albuminuria reduction was not associated with changes in body weight and Hb suggests that the albuminuria-reducing efficacy of atrasentan is not impaired by fluid retention.
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Affiliation(s)
- Donald E Kohan
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.
| | - Hiddo J Lambers Heerspink
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Blai Coll
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Dennis Andress
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - John J Brennan
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Dalane W Kitzman
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Ricardo Correa-Rotter
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Hirofumi Makino
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Vlado Perkovic
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Fan Fan Hou
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Giuseppe Remuzzi
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Sheldon W Tobe
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Robert Toto
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Hans-Henrik Parving
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
| | - Dick de Zeeuw
- Due to the number of contributing authors, the affiliations are provided in the Supplemental Material
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230
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Škrtić M, Lytvyn Y, Yang GK, Yip P, Lai V, Silverman M, Cherney DZI. Glomerular haemodynamic profile of patients with Type 1 diabetes compared with healthy control subjects. Diabet Med 2015; 32:972-9. [PMID: 25662770 DOI: 10.1111/dme.12717] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/04/2015] [Indexed: 11/28/2022]
Abstract
AIMS To evaluate the glomerular haemodynamic profile of patients with Type 1 diabetes with either renal hyperfiltration (GFR ≥ 135 ml/min/1.73 m2 ) or renal normofiltration (GFR 90-134 ml/min/1.73 m2 ) during euglycaemic and hyperglycaemic conditions, and to compare this profile with that of a similar group of healthy control subjects. METHODS Gomez's equations were used to derive afferent and efferent arteriolar resistances, glomerular hydrostatic pressure and filtration pressure. RESULTS At baseline, during clamped euglycaemia, patients with Type 1 diabetes and hyperfiltration had lower mean ± sd afferent arteriolar resistance than both those with Type 1 diabetes and normofiltration (914 ± 494 vs. 2065 ± 597 dyne/s/cm5 ; P < 0.001) and healthy control subjects (1676 ± 707 dyne/s/cm(5) ; p < 0.001). By contrast, efferent arteriolar resistance was similar in the three groups. Patients with Type 1 diabetes and hyperfiltration also had higher mean ± sd glomerular hydrostatic pressure than both healthy control subjects and patients with Type 1 diabetes and normofiltration (66 ± 6 vs. 60 ± 3 vs. 55 ± 3 mmHg; P < 0.05). Similar findings for afferent arteriolar resistance, efferent arteriolar resistance, glomerular hydrostatic pressure and filtration pressure were observed during clamped hyperglycaemia. CONCLUSION Hyperfiltration in Type 1 diabetes is primarily driven by alterations in afferent arteriolar resistance rather than efferent arteriolar resistance. Renal protective therapies should focus on afferent renal arteriolar mechanisms through the use of pharmacological agents that target tubuloglomerular feedback, including sodium-glucose cotransporter 2 inhibitors and incretins.
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Affiliation(s)
- M Škrtić
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Y Lytvyn
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - G K Yang
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - P Yip
- University Health Network, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - V Lai
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - M Silverman
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - D Z I Cherney
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
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231
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Horizon 2020 in Diabetic Kidney Disease: The Clinical Trial Pipeline for Add-On Therapies on Top of Renin Angiotensin System Blockade. J Clin Med 2015; 4:1325-47. [PMID: 26239562 PMCID: PMC4485003 DOI: 10.3390/jcm4061325] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetic kidney disease is the most frequent cause of end-stage renal disease. This implies failure of current therapeutic approaches based on renin-angiotensin system (RAS) blockade. Recent phase 3 clinical trials of paricalcitol in early diabetic kidney disease and bardoxolone methyl in advanced diabetic kidney disease failed to meet the primary endpoint or terminated on safety concerns, respectively. However, various novel strategies are undergoing phase 2 and 3 randomized controlled trials targeting inflammation, fibrosis and signaling pathways. Among agents currently undergoing trials that may modify the clinical practice on top of RAS blockade in a 5-year horizon, anti-inflammatory agents currently hold the most promise while anti-fibrotic agents have so far disappointed. Pentoxifylline, an anti-inflammatory agent already in clinical use, was recently reported to delay estimated glomerular filtration rate (eGFR) loss in chronic kidney disease (CKD) stage 3–4 diabetic kidney disease when associated with RAS blockade and promising phase 2 data are available for the pentoxifylline derivative CTP-499. Among agents targeting chemokines or chemokine receptors, the oral small molecule C-C chemokine receptor type 2 (CCR2) inhibitor CCX140 decreased albuminuria and eGFR loss in phase 2 trials. A dose-finding trial of the anti-IL-1β antibody gevokizumab in diabetic kidney disease will start in 2015. However, clinical development is most advanced for the endothelin receptor A blocker atrasentan, which is undergoing a phase 3 trial with a primary outcome of preserving eGFR. The potential for success of these approaches and other pipeline agents is discussed in detail.
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232
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Tobe S, Kohan DE, Singarayer R. Endothelin Receptor Antagonists: New Hope for Renal Protection? Curr Hypertens Rep 2015; 17:57. [DOI: 10.1007/s11906-015-0568-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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233
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Fried LF, Lewis J. Albuminuria is Not an Appropriate Therapeutic Target in Patients with CKD: The Con View. Clin J Am Soc Nephrol 2015; 10:1089-93. [PMID: 25887070 PMCID: PMC4455218 DOI: 10.2215/cjn.10681014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Albuminuria is a risk factor for progression of kidney disease. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers slow the progression to ESRD, an effect that is correlated with reduction in albuminuria. This has led to the hypothesis that albuminuria should be a target for therapy. This work argues that there are issues with this hypothesis. The previously reported studies were not designed to test the hypothesis that achieving a specific albuminuria target would be beneficial in and of itself irrespective the mechanism used to achieve that goal. One cannot assume that the beneficial effect observed was causally related to the effect on albuminuria or that it would extend to other interventions. Most importantly, it is not known if the approach of maximizing therapy to reduce proteinuria is safe. Recent studies have shown that combining renin-angiotensin system therapies decreases albuminuria without significant clinical benefit but with increased risk of adverse events. More studies are needed, but at this time, albuminuria has not jumped the hurdle needed to be accepted as a surrogate end point or target for treatment. Primum non nocere, first do no harm.
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Affiliation(s)
- Linda F Fried
- Renal Section, Veterans Affairs Pittsburgh Healthcare System and Departments of Medicine and Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Julia Lewis
- Department of Medicine, Division of Nephrology and Hypertension, Vanderbilt University School of Medicine, Nashville, Tennessee
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234
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Abstract
Diabetic kidney disease (DKD) remains the most common cause of chronic kidney disease and multiple therapeutic agents, primarily targeted at the renin-angiotensin system, have been assessed. Their only partial effectiveness in slowing down progression to end-stage renal disease, points out an evident need for additional effective therapies. In the context of diabetes, endothelin-1 (ET-1) has been implicated in vasoconstriction, renal injury, mesangial proliferation, glomerulosclerosis, fibrosis and inflammation, largely through activation of its endothelin A (ETA) receptor. Therefore, endothelin receptor antagonists have been proposed as potential drug targets. In experimental models of DKD, endothelin receptor antagonists have been described to improve renal injury and fibrosis, whereas clinical trials in DKD patients have shown an antiproteinuric effect. Currently, its renoprotective effect in a long-time clinical trial is being tested. This review focuses on the localization of endothelin receptors (ETA and ETB) within the kidney, as well as the ET-1 functions through them. In addition, we summarize the therapeutic benefit of endothelin receptor antagonists in experimental and human studies and the adverse effects that have been described.
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235
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Palmer SC, Mavridis D, Navarese E, Craig JC, Tonelli M, Salanti G, Wiebe N, Ruospo M, Wheeler DC, Strippoli GFM. Comparative efficacy and safety of blood pressure-lowering agents in adults with diabetes and kidney disease: a network meta-analysis. Lancet 2015; 385:2047-56. [PMID: 26009228 DOI: 10.1016/s0140-6736(14)62459-4] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The comparative efficacy and safety of pharmacological agents to lower blood pressure in adults with diabetes and kidney disease remains controversial. We aimed to investigate the benefits and harms of blood pressure-lowering drugs in this population of patients. METHODS We did a network meta-analysis of randomised trials from around the world comparing blood pressure-lowering agents in adults with diabetic kidney disease. Electronic databases (the Cochrane Collaboration, Medline, and Embase) were searched systematically up to January, 2014, for trials in adults with diabetes and kidney disease comparing orally administered blood pressure-lowering drugs. Primary outcomes were all-cause mortality and end-stage kidney disease. We also assessed secondary safety and cardiovascular outcomes. We did random-effects network meta-analysis to obtain estimates for primary and secondary outcomes and we presented these estimates as odds ratios or standardised mean differences with 95% CIs. We ranked the comparative effects of all drugs against placebo with surface under the cumulative ranking (SUCRA) probabilities. FINDINGS 157 studies comprising 43,256 participants, mostly with type 2 diabetes and chronic kidney disease, were included in the network meta-analysis. No drug regimen was more effective than placebo for reducing all-cause mortality. However, compared with placebo, end-stage renal disease was significantly less likely after dual treatment with an angiotensin-receptor blocker (ARB) and an angiotensin-converting-enzyme (ACE) inhibitor (odds ratio 0·62, 95% CI 0·43-0·90) and after ARB monotherapy (0·77, 0·65-0·92). No regimen significantly increased hyperkalaemia or acute kidney injury, although combined ACE inhibitor and ARB treatment had the lowest rank among all interventions because of borderline increases in estimated risks of these harms (odds ratio 2·69, 95% CI 0·97-7·47 for hyperkalaemia; 2·69, 0·98-7·38 for acute kidney injury). INTERPRETATION No blood pressure-lowering strategy prolonged survival in adults with diabetes and kidney disease. ACE inhibitors and ARBs, alone or in combination, were the most effective strategies against end-stage kidney disease. Any benefits of combined ACE inhibitor and ARB treatment need to be balanced against potential harms of hyperkalaemia and acute kidney injury. FUNDING Canterbury Medical Research Foundation, Italian Medicines Agency.
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Affiliation(s)
- Suetonia C Palmer
- Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Dimitris Mavridis
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece; Department of Primary Education, University of Ioannina, Ioannina, Greece
| | - Eliano Navarese
- Department of Cardiology and Internal Medicine, Nicolaus Copernicus University, Collegium Medicum, Bydgoszcz, Poland
| | - Jonathan C Craig
- Sydney School of Public Health, University of Sydney, Sydney, Australia
| | - Marcello Tonelli
- Cumming School of Medicine, Health Sciences Centre, University of Calgary, Calgary, AB, Canada
| | - Georgia Salanti
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - Natasha Wiebe
- Department of Medicine, Division of Nephrology and Immunology, University of Alberta, AB, Canada
| | - Marinella Ruospo
- Department of Translational Medicine, Division of Nephrology and Transplantation, Amedeo Avogadro University of Eastern Piedmont, Novara, Italy; Diaverum Medical Scientific Office, Diaverum Sweden AB, Lund, Sweden
| | - David C Wheeler
- Royal Free and University College Medical School, London, UK
| | - Giovanni F M Strippoli
- Sydney School of Public Health, University of Sydney, Sydney, Australia; Diaverum Medical Scientific Office, Diaverum Sweden AB, Lund, Sweden; Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
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236
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Efficacy and safety of tangshen formula on patients with type 2 diabetic kidney disease: a multicenter double-blinded randomized placebo-controlled trial. PLoS One 2015; 10:e0126027. [PMID: 25938778 PMCID: PMC4418676 DOI: 10.1371/journal.pone.0126027] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 03/26/2015] [Indexed: 12/12/2022] Open
Abstract
Background Persons with diabetes are at high risk of developing diabetic kidney disease (DKD), which is associated with high morbidity and mortality. Current drug therapies for DKD, such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are not entirely satisfactory. This study aimed to evaluate the additional benefit and safety of the Chinese herbal granule Tangshen Formula (TSF) in treating DKD. Methods The study was designed as a six-center randomized, double-blind, placebo-controlled trial. From April 2007 through December 2009, 180 patients with DKD were enrolled. In addition to conventional treatment with ACEIs or ARBs, 122 participants were randomly assigned to receive TSF and 58 participants to receive placebo for 24 weeks. Primary outcome was urinary protein level, measured by urinary albumin excretion rate (UAER) for participants with microalbuminuria, 24-hour urinary protein (24h UP) for participants with macroalbuminuria. Secondary outcomes included renal function, serum lipids, quality of life, symptoms, and adverse events. Findings After 24 weeks of treatment, no statistically significant difference in UAER (TSF −19.53 μg/min compared with placebo −7.01 μg/min, with a mean difference of −12.52 μg/min; 95%CI, −68.67 to 43.63, P = 0.696) was found between TSF and placebo groups. However, TSF displayed a statistically significant decrease in 24h UP (TSF−0.21 g compared with placebo 0.36 g, with a mean difference of −0.57g; 95%CI, −1.05 to −0.09, P = 0.024). Estimated glomerular filtration rate (eGFR) was improved in both patients with microalbuminuria and macroalbuminuria, with a mean difference of 15.51 ml/min/1.73 m2 (95%CI, 3.71 to 27.31), 9.01 ml/min/1.73 m2 (95%CI, −0.10 to 18.13), respectively. Other secondary outcomes showed no statistically significant difference between groups or in the incidence of adverse events. Conclusions Based on conventional treatments, TSF appears to provide additional benefits compared with placebo in decreasing proteinuria and improving eGFR in DKD patients with macroalbuminuria. Nevertheless, further study is needed to evaluate TSF treating patients with microalbuminuria. Trial Registration Chinese Clinical Trial Registry ChiCTR-TRC-10000843
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237
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Toth-Manikowski S, Atta MG. Diabetic Kidney Disease: Pathophysiology and Therapeutic Targets. J Diabetes Res 2015; 2015:697010. [PMID: 26064987 PMCID: PMC4430644 DOI: 10.1155/2015/697010] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/17/2015] [Indexed: 12/13/2022] Open
Abstract
Diabetes is a worldwide epidemic that has led to a rise in diabetic kidney disease (DKD). Over the past two decades, there has been significant clarification of the various pathways implicated in the pathogenesis of DKD. Nonetheless, very little has changed in the way clinicians manage patients with this disorder. Indeed, treatment is primarily centered on controlling hyperglycemia and hypertension and inhibiting the renin-angiotensin system. The purpose of this review is to describe the current understanding of how the hemodynamic, metabolic, inflammatory, and alternative pathways are all entangled in pathogenesis of DKD and detail the various therapeutic targets that may one day play a role in quelling this epidemic.
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Affiliation(s)
- Stephanie Toth-Manikowski
- Division of Nephrology, Johns Hopkins University, 1830 E. Monument Street, Suite 416, Baltimore, MD 21287, USA
| | - Mohamed G. Atta
- Division of Nephrology, Johns Hopkins University, 1830 E. Monument Street, Suite 416, Baltimore, MD 21287, USA
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238
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Walley RJ, Smith CL, Gale JD, Woodward P. Advantages of a wholly Bayesian approach to assessing efficacy in early drug development: a case study. Pharm Stat 2015; 14:205-15. [PMID: 25865949 DOI: 10.1002/pst.1675] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 11/12/2014] [Accepted: 02/17/2015] [Indexed: 01/21/2023]
Abstract
This paper illustrates how the design and statistical analysis of the primary endpoint of a proof-of-concept study can be formulated within a Bayesian framework and is motivated by and illustrated with a Pfizer case study in chronic kidney disease. It is shown how decision criteria for success can be formulated, and how the study design can be assessed in relation to these, both using the traditional approach of probability of success conditional on the true treatment difference and also using Bayesian assurance and pre-posterior probabilities. The case study illustrates how an informative prior on placebo response can have a dramatic effect in reducing sample size, saving time and resource, and we argue that in some cases, it can be considered unethical not to include relevant literature data in this way.
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Affiliation(s)
| | - Claire L Smith
- Eli Lilly and Company Limited, Erl Wood Manor, Windlesham, GU20 6PH, UK
| | | | - Phil Woodward
- Pfizer, Neusentis, The Portway Building, Granta Park, Cambridge, CB21 6GS, UK
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239
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Quiroga B, Arroyo D, de Arriba G. Present and future in the treatment of diabetic kidney disease. J Diabetes Res 2015; 2015:801348. [PMID: 25945357 PMCID: PMC4405221 DOI: 10.1155/2015/801348] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 12/21/2022] Open
Abstract
Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade.
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Affiliation(s)
- Borja Quiroga
- Nephrology Unit, Hospital Universitario de Guadalajara, Spain
| | - David Arroyo
- Nephrology Unit, Hospital Universitari Arnau de Vilanova, Lleida, Spain
| | - Gabriel de Arriba
- Nephrology Unit, Hospital Universitario de Guadalajara, Spain
- Medicine and Medicine Specialities Department, Universidad de Alcalá (UAH), Madrid, Spain
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240
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Endothelin-1 critically influences cardiac function via superoxide-MMP9 cascade. Proc Natl Acad Sci U S A 2015; 112:5141-6. [PMID: 25848038 DOI: 10.1073/pnas.1504557112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have generated low-expressing and high-expressing endothelin-1 genes (L and H) and have bred mice with four levels of expression: L/L, ∼20%; L/+, ∼65%; +/+ (wild type), 100%; and H/+, ∼350%. The hypomorphic L allele can be spatiotemporally switched to the hypermorphic H allele by Cre-loxP recombination. Young adult L/L and L/+ mice have dilated cardiomyopathy, hypertension, and increased plasma volumes, together with increased ventricular superoxide levels, increased matrix metalloproteinase 9 (Mmp9) expression, and reduced ventricular stiffness. H/+ mice have decreased plasma volumes and significantly heavy stiff hearts. Global or cardiomyocyte-specific switching expression from L to H normalized the abnormalities already present in young adult L/L mice. An epithelial sodium channel antagonist normalized plasma volume and blood pressure, but only partially corrected the cardiomyopathy. A superoxide dismutase mimetic made superoxide levels subnormal, reduced Mmp9 overexpression, and substantially improved cardiac function. Genetic absence of Mmp9 also improved cardiac function, but increased superoxide remained. We conclude that endothelin-1 is critical for maintaining normal contractile function, for controlling superoxide and Mmp9 levels, and for ensuring that the myocardium has sufficient collagen to prevent overstretching. Even a modest (∼35%) decrease in endothelin-1 gene (Edn1) expression is sufficient to cause cardiac dysfunction.
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241
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Wang L, Jirka G, Rosenberg PB, Buckley AF, Gomez JA, Fields TA, Winn MP, Spurney RF. Gq signaling causes glomerular injury by activating TRPC6. J Clin Invest 2015; 125:1913-26. [PMID: 25844902 DOI: 10.1172/jci76767] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 02/27/2015] [Indexed: 01/07/2023] Open
Abstract
Familial forms of focal segmental glomerulosclerosis (FSGS) have been linked to gain-of-function mutations in the gene encoding the transient receptor potential channel C6 (TRPC6). GPCRs coupled to Gq signaling activate TRPC6, suggesting that Gq-dependent TRPC6 activation underlies glomerular diseases. Here, we developed a murine model in which a constitutively active Gq α subunit (Gq(Q209L), referred to herein as GqQ>L) is specifically expressed in podocytes and examined the effects of this mutation in response to puromycin aminonucleoside (PAN) nephrosis. We found that compared with control animals, animals expressing GqQ>L exhibited robust albuminuria, structural features of FSGS, and reduced numbers of glomerular podocytes. Gq activation stimulated calcineurin (CN) activity, resulting in CN-dependent upregulation of TRPC6 in murine kidneys. Deletion of TRPC6 in GqQ>L-expressing mice prevented FSGS development and inhibited both tubular damage and podocyte loss induced by PAN nephrosis. Similarly, administration of the CN inhibitor FK506 reduced proteinuria and tubular injury but had more modest effects on glomerular pathology and podocyte numbers in animals with constitutive Gq activation. Moreover, these Gq-dependent effects on podocyte injury were generalizable to diabetic kidney disease, as expression of GqQ>L promoted albuminuria, mesangial expansion, and increased glomerular basement membrane width in diabetic mice. Together, these results suggest that targeting Gq/TRPC6 signaling may have therapeutic benefits for the treatment of glomerular diseases.
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MESH Headings
- Albuminuria/chemically induced
- Animals
- Calcineurin/metabolism
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/genetics
- Diabetic Nephropathies/genetics
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/pathology
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Gene Deletion
- Genes, Reporter
- Glomerulosclerosis, Focal Segmental/chemically induced
- Glomerulosclerosis, Focal Segmental/genetics
- Glomerulosclerosis, Focal Segmental/pathology
- HEK293 Cells
- Humans
- Kidney Glomerulus/pathology
- Kidney Tubules/pathology
- Mice
- Mice, Mutant Strains
- Mice, Transgenic
- NFATC Transcription Factors/metabolism
- Podocytes/metabolism
- Point Mutation
- Puromycin Aminonucleoside/toxicity
- Recombinant Fusion Proteins/metabolism
- Signal Transduction
- TRPC Cation Channels/biosynthesis
- TRPC Cation Channels/deficiency
- TRPC Cation Channels/genetics
- TRPC Cation Channels/physiology
- TRPC6 Cation Channel
- Tacrolimus/pharmacology
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242
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Endothelin receptors, renal effects and blood pressure. Curr Opin Pharmacol 2015; 21:25-34. [DOI: 10.1016/j.coph.2014.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022]
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243
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Lee SY, Kim SI, Choi ME. Therapeutic targets for treating fibrotic kidney diseases. Transl Res 2015; 165:512-30. [PMID: 25176603 PMCID: PMC4326607 DOI: 10.1016/j.trsl.2014.07.010] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/24/2014] [Accepted: 07/28/2014] [Indexed: 12/11/2022]
Abstract
Renal fibrosis is the hallmark of virtually all progressive kidney diseases and strongly correlates with the deterioration of kidney function. The renin-angiotensin-aldosterone system blockade is central to the current treatment of patients with chronic kidney disease (CKD) for the renoprotective effects aimed to prevent or slow progression to end-stage renal disease (ESRD). However, the incidence of CKD is still increasing, and there is a critical need for new therapeutics. Here, we review novel strategies targeting various components implicated in the fibrogenic pathway to inhibit or retard the loss of kidney function. We focus, in particular, on antifibrotic approaches that target transforming growth factor (TGF)-β1, a key mediator of kidney fibrosis, and exciting new data on the role of autophagy. Bone morphogenetic protein (BMP)-7 and connective tissue growth factor (CTGF) are highlighted as modulators of profibrotic TGF-β activity. BMP-7 has a protective role against TGF-β1 in kidney fibrosis, whereas CTGF enhances TGF-β-mediated fibrosis. We also discuss recent advances in the development of additional strategies for antifibrotic therapy. These include strategies targeting chemokine pathways via CC chemokine receptors 1 and 2 to modulate the inflammatory response, inhibition of phosphodiesterase to restore nitric oxide-cyclic 3',5'-guanosine monophosphate function, inhibition of nicotinamide adenine dinucleotide phosphate oxidase 1 and 4 to suppress reactive oxygen species production, and inhibition of endothelin 1 or tumor necrosis factor α to ameliorate progressive renal fibrosis. Furthermore, a brief overview of some of the biomarkers of kidney fibrosis is currently being explored that may improve the ability to monitor antifibrotic therapies. It is hoped that evidence based on the preclinical and clinical data discussed in this review leads to novel antifibrotic therapies effective in patients with CKD to prevent or delay progression to ESRD.
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Affiliation(s)
- So-Young Lee
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Department of Internal Medicine, Bundang CHA Medical Center, CHA University School of Medicine, Seongnam, South Korea
| | - Sung I Kim
- Division of Nephrology and Hypertension, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY
| | - Mary E Choi
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Division of Nephrology and Hypertension, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY.
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244
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Shayman JA. Challenges and opportunities in the development of therapeutics for chronic kidney disease. Transl Res 2015; 165:482-7. [PMID: 25218118 DOI: 10.1016/j.trsl.2014.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 11/25/2022]
Affiliation(s)
- James A Shayman
- Nephrology Division, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Mich.
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245
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Abstract
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
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Affiliation(s)
- Mattias Carlström
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher S Wilcox
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J Arendshorst
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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246
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247
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Abstract
All three members of the endothelin (ET) family of peptides, ET-1, ET-2, and ET-3, are expressed in the human kidney, with ET-1 being the predominant isoform. ET-1 and ET-2 bind to two G-protein-coupled receptors, ETA and ETB, whereas at physiological concentrations ET-3 has little affinity for the ET(A) receptor. The human kidney is unusual among the peripheral organs in expressing a high density of ET(B). The renal vascular endothelium only expresses the ET(B) subtype and ET-1 acts in an autocrine or paracrine manner to release vasodilators. Endothelial ETB in kidney, as well as liver and lungs, also has a critical role in scavenging ET-1 from the plasma. The third major function is ET-1 activation of ET(B) in in the nephron to reduce salt and water re-absorption. In contrast, ET(A) predominate on smooth muscle, causing vasoconstriction and mediating many of the pathophysiological actions of ET-1. The role of the two receptors has been delineated using highly selective ET(A) (BQ123, TAK-044) and ET(B) (BQ788) peptide antagonists. Nonpeptide antagonists, bosentan, macitentan, and ambrisentan, that are either mixed ET(A)/ET(B) antagonists or display ET(A) selectivity, have been approved for clinical use but to date are limited to pulmonary hypertension. Ambrisentan is in clinical trials in patients with type 2 diabetic nephropathy. This review summarizes ET-receptor antagonism in the human kidney, and considers the relative merits of selective versus nonselective antagonism in renal disease.
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Affiliation(s)
- Janet J Maguire
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke׳s Hospital, Cambridge, United Kingdom
| | - Anthony P Davenport
- Clinical Pharmacology Unit, University of Cambridge, Addenbrooke׳s Hospital, Cambridge, United Kingdom.
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248
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Pandit MM, Inscho EW, Zhang S, Seki T, Rohatgi R, Gusella L, Kishore B, Kohan DE. Flow regulation of endothelin-1 production in the inner medullary collecting duct. Am J Physiol Renal Physiol 2015; 308:F541-52. [PMID: 25587122 DOI: 10.1152/ajprenal.00456.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Collecting duct-derived endothelin (ET)-1 is an autocrine inhibitor of Na(+) and water reabsorption; its deficiency causes hypertension and water retention. Extracellular fluid volume expansion increases collecting duct ET-1, thereby promoting natriuresis and diuresis; however, how this coupling between volume expansion and collecting duct ET-1 occurs is incompletely understood. One possibility is that volume expansion increases tubular fluid flow. To investigate this, cultured IMCD3 cells were subjected to static or flow conditions. Exposure to a shear stress of 2 dyn/cm(2) for 2 h increased ET-1 mRNA content by ∼2.3-fold. Absence of perfusate Ca(2+), chelation of intracellular Ca(2+), or inhibition of Ca(2+) signaling (calmodulin, Ca(2+)/calmodulin-dependent kinase, calcineurin, PKC, or phospholipase C) prevented the flow response. Evaluation of possible flow-activated Ca(2+) entry pathways revealed no role for transient receptor potential (TRP)C3, TRPC6, and TRPV4; however, cells with TRPP2 (polycystin-2) knockdown had no ET-1 flow response. Flow increased intracellular Ca(2+) was blunted in TRPP2 knockdown cells. Nonspecific blockade of P2 receptors, as well as specific inhibition of P2X7 and P2Y2 receptors, prevented the ET-1 flow response. The ET-1 flow response was not affected by inhibition of either epithelial Na(+) channels or the mitochondrial Na(+)/Ca(2+) exchanger. Taken together, these findings provide evidence that in IMCD3 cells, flow, via polycystin-2 and P2 receptors, engages Ca(2+)-dependent signaling pathways that stimulate ET-1 synthesis.
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Affiliation(s)
- Meghana M Pandit
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah; Department of Pharmaceutics and Pharmaceutical Chemistry, Salt Lake City, Utah
| | | | - Shali Zhang
- University of Alabama at Birmingham, Birmingham, Alabama
| | - Tsugio Seki
- Department of Medical Education, California Northstate University, Elk Grove, California
| | - Rajeev Rohatgi
- Department of Medicine, James J. Peter Veterans Affairs Medical Center, Bronx, New York; Department of Medicine and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Luca Gusella
- Department of Medicine, James J. Peter Veterans Affairs Medical Center, Bronx, New York; Department of Medicine and Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Bellamkonda Kishore
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah; Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah; Department of Pharmaceutics and Pharmaceutical Chemistry, Salt Lake City, Utah; Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
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249
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Van Laecke S, Van Biesen W, Vanholder R. The paradox of bardoxolone methyl: a call for every witness on the stand? Diabetes Obes Metab 2015; 17:9-14. [PMID: 25041694 DOI: 10.1111/dom.12356] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 07/07/2014] [Accepted: 07/07/2014] [Indexed: 01/09/2023]
Abstract
People with type 2 diabetes and chronic kidney disease (CKD) remain an extremely vulnerable population with increased cardiovascular morbidity, mortality and mounting societal costs. As such, any effort to improve their dismal outcome is heavily supported. Yet, most drugs fail to replicate the promising signals of early experiments in humans in large and methodologically sound trials. As a recent example, an independent data and safety committee advised the termination of a phase 3 trial due to excessive cardiovascular disease and especially heart failure in patients allocated to the antioxidant synthetic triterpenoid bardoxolone methyl versus placebo. We evaluate the reasons why this outcome in hindsight was possibly not totally unexpected and develop a mechanistic model that shows that the consistent drop in serum magnesium concentration in patients exposed to bardoxolone methyl might have contributed to the development of heart failure. As such, this trial, despite its negative outcome, might provide additional pieces of the puzzle enabling us to get a better grip on diseases that share increased inflammation and oxidative stress, such as type 2 diabetes, metabolic syndrome, heart failure and CKD.
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Affiliation(s)
- S Van Laecke
- Renal Division, Ghent University Hospital, Ghent, Belgium
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250
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Zanatta CM, Crispim D, Sortica DA, Klassmann LP, Gross JL, Gerchman F, Canani LH. Endothelin-1 gene polymorphisms and diabetic kidney disease in patients with type 2 diabetes mellitus. Diabetol Metab Syndr 2015; 7:103. [PMID: 26594247 PMCID: PMC4653842 DOI: 10.1186/s13098-015-0093-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 11/02/2015] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND AND AIMS Diabetic kidney disease (DKD) is the leading cause of end stage renal disease worldwide and is associated with increased cardiovascular mortality. The endothelin system has been implicated in the pathogenesis of arterial hypertension and renal dysfunction. In the present study, the association of DKD with polymorphisms in ET-1 (EDN1) and ETRA (EDNRA) genes was analyzed in patients with type 2 diabetes mellitus (T2DM). METHODS A case-control study was conducted in 548 white T2DM patients. Patients with proteinuria or on dialysis were considered cases and patients with normoalbuminuria were considered controls. Two polymorphisms in the EDN1 gene (rs1800541 and rs57072783) and five in EDNRA gene (rs6842241; rs4835083; rs4639051; rs5333 and rs5343) were genotyped and haplotype analyses were performed. RESULTS The presence of rs57072783 T allele (TT/TG vs. GG) or rs1800541 G allele (GG/GT vs. TT) protected against DKD (OR = 0.69, 95 % CI 0.48-0.99, P = 0.049; and OR = 0.60, 95 % CI 0.41-0.88, P = 0.009, respectively). However in multivariate analyses, only the rs1800541 G allele remained independently associated with DKD (P = 0.046). CONCLUSIONS The present study shows that ET-1 could be involved in the pathogenesis of DKD in patients with T2DM.
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Affiliation(s)
| | - Daisy Crispim
- />Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- />Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, RS Brazil
| | | | | | - Jorge L. Gross
- />Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- />Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, RS Brazil
| | - Fernando Gerchman
- />Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- />Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, RS Brazil
| | - Luís H. Canani
- />Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- />Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, RS Brazil
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