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Xu C. Extra-adrenal aldosterone: a mini review focusing on the physiology and pathophysiology of intrarenal aldosterone. Endocrine 2024; 83:285-301. [PMID: 37847370 DOI: 10.1007/s12020-023-03566-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 10/08/2023] [Indexed: 10/18/2023]
Abstract
PURPOSE Accumulating evidence has demonstrated the existence of extra-adrenal aldosterone in various tissues, including the brain, heart, vascular, adipocyte, and kidney, mainly based on the detection of the CYP11B2 (aldosterone synthase, cytochrome P450, family 11, subfamily B, polypeptide 2) expression using semi-quantitative methods including reverse transcription-polymerase chain reaction and antibody-based western blotting, as well as local tissue aldosterone levels by antibody-based immunosorbent assays. This mini-review highlights the current evidence and challenges in extra-adrenal aldosterone, focusing on intrarenal aldosterone. METHODS A narrative review. RESULTS Locally synthesized aldosterone may play a vital role in various physio-pathological processes, especially cardiovascular events. The site of local aldosterone synthesis in the kidney may include the mesangial cells, podocytes, proximal tubules, and collecting ducts. The synthesis of renal aldosterone may be regulated by (pro)renin receptor/(pro)renin, angiotensin II/Angiotensin II type 1 receptor, wnt/β-catenin, cyclooxygenase-2/prostaglandin E2, and klotho. Enhanced renal aldosterone release promotes Na+ reabsorption and K+ excretion in the distal nephron and may contribute to the progress of diabetic nephropathy and salt-related hypertension. CONCLUSIONS Inhibition of intrarenal aldosterone signaling by aldosterone synthase inhibitors or mineralocorticoid receptor antagonists may be a hopeful pharmacological technique for the therapy of diabetic nephropathy and saltrelated hypertension. Yet, current reports are often conflicting or ambiguous, leading many to question whether extra-adrenal aldosterone exists, or whether it is of any physiological and pathophysiological significance.
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Affiliation(s)
- Chuanming Xu
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang, 330002, Jiangxi, China.
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Launonen H, Luiskari L, Linden J, Siltari A, Salmenkari H, Korpela R, Vapaatalo H. Adverse effects of an aldosterone synthase (CYP11B2) inhibitor, fadrozole (FAD286), on inflamed rat colon. Basic Clin Pharmacol Toxicol 2023; 133:211-225. [PMID: 37345281 DOI: 10.1111/bcpt.13918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 06/23/2023]
Abstract
Recently, we described local aldosterone production in the murine large intestine. Upregulated local aldosterone synthesis in different tissues has been linked with inflammatory conditions, which have been attenuated by the aldosterone synthase (CYP11B2) inhibitor, fadrozole (FAD286). Therefore, we investigated the effect of inhibition of intestinal aldosterone synthesis on the development of intestinal inflammation. Sprague-Dawley rats were administered 5% (v/w) dextran sodium sulphate (DSS) for 7 days with or without daily FAD286 (30 mg/kg/d) subcutaneous injections on 3 days before, during and one day after DSS. Tissue aldosterone concentrations were evaluated by ELISA, CYP11B2 by Western blot and RT-qPCR. FAD286 halved adrenal aldosterone production but, intriguingly, increased the colonic aldosterone concentration. The lack of inhibitory effect of FAD286 in the colon might have been affected by the smaller size of colonic vs. adrenal CYP11B2, as seen in Western blot. When combined with DSS, FAD286 aggravated the macroscopic and histological signs of intestinal inflammation, lowered the animals' body weight gain and increased the incidence of gastrointestinal bleeding and the permeability to iohexol in comparison to DSS-animals. To conclude, FAD286 exerted harmful effects during intestinal inflammation. Local intestinal aldosterone did not seem to play any role in the inflammatory pathogenesis occurring in the intestine.
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Affiliation(s)
- Hanna Launonen
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
| | - Lotta Luiskari
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
| | - Jere Linden
- Faculty of Veterinary Medicine, Department of Veterinary Biosciences and Finnish Centre for Laboratory Animal Pathology (FCLAP), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Aino Siltari
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Hanne Salmenkari
- Folkhälsan Research Center, Folkhälsan Institute of Genetics, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riitta Korpela
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
- Faculty of Medicine, Human Microbiome Research Program, University of Helsinki, Helsinki, Finland
| | - Heikki Vapaatalo
- Faculty of Medicine, Pharmacology, University of Helsinki, Helsinki, Finland
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Xu C, Chen Y, Ramkumar N, Zou CJ, Sigmund CD, Yang T. Collecting duct renin regulates potassium homeostasis in mice. Acta Physiol (Oxf) 2023; 237:e13899. [PMID: 36264268 PMCID: PMC10754139 DOI: 10.1111/apha.13899] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 10/15/2022] [Accepted: 10/16/2022] [Indexed: 01/03/2023]
Abstract
AIM The kaliuretic action of the renin-angiotensin-aldosterone system (RAAS) is well established as highlighted by hyperkalemia side effect of RAAS inhibitors but such action is usually ascribed to systemic RAAS. The present study addresses the involvement of intrarenal RAAS in K+ homeostasis with emphasis on locally generated renin within the collecting duct (CD). METHODS Wild-type (Floxed) and CD-specific deletion of renin (CD renin KO) mice were treated for 7 days with a high K+ (HK) diet to investigate the role of CD renin in kaliuresis regulation and further define the underlying mechanism with emphasis on analysis of intrarenal aldosterone biosynthesis. RESULTS In floxed mice, renin levels were elevated in the renal medulla and urine following a 1-week HK diet, indicating activation of the intrarenal renin. CD renin KO mice had blunted HK-induced intrarenal renin response and developed impaired kaliuresis and elevated plasma K+ level (4.45 ± 0.14 vs. 3.89 ± 0.04 mM, p < 0.01). In parallel, HK-induced intrarenal aldosterone and CYP11B2 expression along with expression of renal outer medullary K+ channel (ROMK), calcium-activated potassium channel subunit alpha-1 (α-BK), α-Na+ -K+ -ATPase, and epithelial sodium channel (β-ENaC and cleaved-γ-ENaC) expression were all significantly blunted in CD renin KO mice in contrast to the unaltered responses of plasma aldosterone and adrenal CYP11B2. CONCLUSION Taken together, these results support a kaliuretic action of CD renin during HK intake.
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Affiliation(s)
- Chuanming Xu
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, UT 84132
- Veterans Affairs Medical Center, Salt Lake City, Utah, UT 84132
| | - Yanting Chen
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, UT 84132
- Veterans Affairs Medical Center, Salt Lake City, Utah, UT 84132
| | - Nirupama Ramkumar
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, UT 84132
| | - Chang-Jiang Zou
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, UT 84132
- Veterans Affairs Medical Center, Salt Lake City, Utah, UT 84132
| | - Curt D. Sigmund
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226
| | - Tianxin Yang
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, UT 84132
- Veterans Affairs Medical Center, Salt Lake City, Utah, UT 84132
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Howard ZM, Gomatam CK, Piepho AB, Rafael-Fortney JA. Mineralocorticoid Receptor Signaling in the Inflammatory Skeletal Muscle Microenvironments of Muscular Dystrophy and Acute Injury. Front Pharmacol 2022; 13:942660. [PMID: 35837290 PMCID: PMC9273774 DOI: 10.3389/fphar.2022.942660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a striated muscle degenerative disease due to loss of functional dystrophin protein. Loss of dystrophin results in susceptibility of muscle membranes to damage, leading to muscle degeneration and continuous inflammation and fibrosis that further exacerbate pathology. Long-term glucocorticoid receptor (GR) agonist treatment, the current standard-of-care for DMD, modestly improves prognosis but has serious side effects. The mineralocorticoid receptor (MR), a ligand-activated transcription factor present in many cell types, has been implicated as a therapeutic target for DMD. MR antagonists (MRAs) have fewer side effects than GR agonists and are used clinically for heart failure. MRA efficacy has recently been demonstrated for DMD cardiomyopathy and in preclinical studies, MRAs also alleviate dystrophic skeletal muscle pathology. MRAs lead to improvements in muscle force and membrane stability and reductions in degeneration, inflammation, and fibrosis in dystrophic muscles. Myofiber-specific MR knockout leads to most of these improvements, supporting an MR-dependent mechanism of action, but MRAs additionally stabilize myofiber membranes in an MR-independent manner. Immune cell MR signaling in dystrophic and acutely injured normal muscle contributes to wound healing, and myeloid-specific MR knockout is detrimental. More research is needed to fully elucidate MR signaling in striated muscle microenvironments. Direct comparisons of genomic and non-genomic effects of glucocorticoids and MRAs on skeletal muscles and heart will contribute to optimal temporal use of these drugs, since they compete for binding conserved receptors. Despite the advent of genetic medicines, therapies targeting inflammation and fibrosis will be necessary to achieve optimal patient outcomes.
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Pang Z, Launonen H, Korpela R, Vapaatalo H. Local aldosterone synthesis in the large intestine of mouse: An ex vivo incubation study. J Int Med Res 2022; 50:3000605221105163. [PMID: 35748030 PMCID: PMC9248050 DOI: 10.1177/03000605221105163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Objective To investigate the regulation of local aldosterone synthesis by physiological
stimulants in the murine gut. Methods Male mice were fed for 14 days with normal, high (1.6%) or low (0.01%) sodium
diets. Tissue liver receptor homolog-1 and aldosterone in the colon and
caecum were detected using an enzyme-linked immunosorbent assay (ELISA).
Released corticosterone and aldosterone in tissue incubation experiments
after stimulation with angiotensin II (Ang II) and dibutyryl-cAMP (DBA; the
second messenger of adrenocorticotropic hormone) were assayed using an
ELISA. Tissue aldosterone synthase (CYP11B2) protein levels were measured
using an ELISA and Western blots. Results In incubated colon tissues, aldosterone synthase levels were increased by a
low-sodium diet; and by Ang II and DBA in the normal diet group. Release of
aldosterone into the incubation buffer was increased from the colon by a
low-sodium diet and decreased by a high-sodium diet in parallel with changes
in aldosterone synthase levels. In mice fed a normal diet, colon incubation
with both Ang II and DBA increased the release of aldosterone as well as its
precursor corticosterone. Conclusion Local aldosterone synthesis in the large intestine is stimulated by a
low-sodium diet, dibutyryl-cAMP and Ang II similar to the adrenal
glands.
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Affiliation(s)
- Zan Pang
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hanna Launonen
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riitta Korpela
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Human Microbiome Research Programme, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Heikki Vapaatalo
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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Xu C, Yang G, Fu Z, Chen Y, Xie S, Wang F, Yang T. Na +-Retaining Action of COX-2 (Cyclooxygenase-2)/EP 1 Pathway in the Collecting Duct via Activation of Intrarenal Renin-Angiotensin-Aldosterone System and Epithelial Sodium Channel. Hypertension 2022; 79:1190-1202. [PMID: 35296155 DOI: 10.1161/hypertensionaha.121.17245] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The collecting duct (CD) is a major site of both biosynthesis and action of prostaglandin E2 as highlighted by the predominant expression of COX-2 (cyclooxygenase-2) and some E-prostanoid (EP) subtypes at this nephron site. The purpose of this study was to determine the relevance and mechanism of CD COX-2/prostaglandin E2/EP1 signaling for the regulation of Na+ hemostasis during Na+ depletion. METHODS Mice with Aqp2Cre-driven deletion of COX-2 (COX-2fl/flAqp2Cre+) or the EP1 subtype (EP1fl/flAqp2Cre+) were generated and the Na+-wasting phenotype of these mice during low-salt (LS) intake was examined. EP subtypes responsible for prostaglandin E2-induced local renin response were analyzed in primary cultured mouse inner medullary CD cells. RESULTS Following 28-day LS intake, COX-2fl/flAqp2Cre+ mice exhibited a higher urinary Na+ excretion and lower cumulative Na+ balance, accompanied with suppressed intrarenal renin, AngII (angiotensin II), and aldosterone, expression of CYP11B2 (cytochrome P450 family 11 subfamily B member 2), and blunted expression of epithelial sodium channel subunits compared to floxed controls (COX-2fl/flAqp2Cre-), whereas no differences were observed for indices of systemic renin-angiotensin-aldosterone system. In cultured CD cells, exposure to prostaglandin E2 stimulated release of soluble (pro)renin receptor, prorenin/renin and aldosterone and the stimulation was more sensitive to antagonism of EP1 as compared other EP subtypes. Subsequently, EP1fl/flAqp2Cre+ mice largely recapitulated Na+-wasting phenotype seen in COX-2fl/flAqp2Cre+ mice. CONCLUSIONS The study for the first time reports that CD COX-2/EP1 pathway might play a key role in maintenance of Na+ homeostasis in the face of Na+ depletion, at least in part, through activation of intrarenal renin-angiotensin-aldosterone-system and epithelial sodium channel.
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Affiliation(s)
- Chuanming Xu
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Guangrui Yang
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Ziwei Fu
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Yanting Chen
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Shiying Xie
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Fei Wang
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
| | - Tianxin Yang
- Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City
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Spencer S, Wheeler‐Jones C, Elliott J. Aldosterone and the mineralocorticoid receptor in renal injury: A potential therapeutic target in feline chronic kidney disease. J Vet Pharmacol Ther 2020; 43:243-267. [PMID: 32128854 PMCID: PMC8614124 DOI: 10.1111/jvp.12848] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/20/2020] [Accepted: 02/09/2020] [Indexed: 12/24/2022]
Abstract
There is a growing body of experimental and clinical evidence supporting mineralocorticoid receptor (MR) activation as a powerful mediator of renal damage in laboratory animals and humans. Multiple pathophysiological mechanisms are proposed, with the strongest evidence supporting aldosterone-induced vasculopathy, exacerbation of oxidative stress and inflammation, and increased growth factor signalling promoting fibroblast proliferation and deranged extracellular matrix homeostasis. Further involvement of the MR is supported by extensive animal model experiments where MR antagonists (such as spironolactone and eplerenone) abrogate renal injury, including ischaemia-induced damage. Additionally, clinical trials have shown MR antagonists to be beneficial in human chronic kidney disease (CKD) in terms of reducing proteinuria and cardiovascular events, though current studies have not evaluated primary end points which allow conclusions to made about whether MR antagonists reduce mortality or slow CKD progression. Although differences between human and feline CKD exist, feline CKD shares many characteristics with human disease including tubulointerstitial fibrosis. This review evaluates the evidence for the role of the MR in renal injury and summarizes the literature concerning aldosterone in feline CKD. MR antagonists may represent a promising therapeutic strategy in feline CKD.
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Affiliation(s)
- Sarah Spencer
- Comparative Biomedical SciencesThe Royal Veterinary CollegeLondonUK
| | | | - Jonathan Elliott
- Comparative Biomedical SciencesThe Royal Veterinary CollegeLondonUK
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Wesson DE, Buysse JM, Bushinsky DA. Mechanisms of Metabolic Acidosis-Induced Kidney Injury in Chronic Kidney Disease. J Am Soc Nephrol 2020; 31:469-482. [PMID: 31988269 DOI: 10.1681/asn.2019070677] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Retrospective analyses and single-center prospective studies identify chronic metabolic acidosis as an independent and modifiable risk factor for progression of CKD. In patients with CKD, untreated chronic metabolic acidosis often leads to an accelerated reduction in GFR. Mechanisms responsible for this reduction include adaptive responses that increase acid excretion but lead to a decline in kidney function. Metabolic acidosis in CKD stimulates production of intrakidney paracrine hormones including angiotensin II, aldosterone, and endothelin-1 (ET-1) that mediate the immediate benefit of increased kidney acid excretion, but their chronic upregulation promotes inflammation and fibrosis. Chronic metabolic acidosis also stimulates ammoniagenesis that increases acid excretion but also leads to ammonia-induced complement activation and deposition of C3 and C5b-9 that can cause tubule-interstitial damage, further worsening disease progression. These effects, along with acid accumulation in kidney tissue, combine to accelerate progression of kidney disease. Treatment of chronic metabolic acidosis attenuates these adaptive responses; reduces levels of angiotensin II, aldosterone, and ET-1; reduces ammoniagenesis; and diminishes inflammation and fibrosis that may lead to slowing of CKD progression.
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Affiliation(s)
- Donald E Wesson
- Baylor Scott & White Health and Wellness Center, Dallas, Texas; .,Department of Internal Medicine, Texas A&M College of Medicine, Bryan, Texas
| | | | - David A Bushinsky
- Division of Nephrology, University of Rochester School of Medicine, Rochester, New York
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Recent insights into sodium and potassium handling by the aldosterone-sensitive distal nephron: a review of the relevant physiology. J Nephrol 2020; 33:431-445. [DOI: 10.1007/s40620-019-00684-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 12/02/2019] [Indexed: 02/07/2023]
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Novel dietary and pharmacologic approaches for acid–base modulation to preserve kidney function and manage uremia. Curr Opin Nephrol Hypertens 2020; 29:39-48. [DOI: 10.1097/mnh.0000000000000568] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ames MK, Atkins CE, Pitt B. The renin-angiotensin-aldosterone system and its suppression. J Vet Intern Med 2019; 33:363-382. [PMID: 30806496 PMCID: PMC6430926 DOI: 10.1111/jvim.15454] [Citation(s) in RCA: 211] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 01/30/2019] [Indexed: 12/11/2022] Open
Abstract
Chronic activation of the renin-angiotensin-aldosterone system (RAAS) promotes and perpetuates the syndromes of congestive heart failure, systemic hypertension, and chronic kidney disease. Excessive circulating and tissue angiotensin II (AngII) and aldosterone levels lead to a pro-fibrotic, -inflammatory, and -hypertrophic milieu that causes remodeling and dysfunction in cardiovascular and renal tissues. Understanding of the role of the RAAS in this abnormal pathologic remodeling has grown over the past few decades and numerous medical therapies aimed at suppressing the RAAS have been developed. Despite this, morbidity from these diseases remains high. Continued investigation into the complexities of the RAAS should help clinicians modulate (suppress or enhance) components of this system and improve quality of life and survival. This review focuses on updates in our understanding of the RAAS and the pathophysiology of AngII and aldosterone excess, reviewing what is known about its suppression in cardiovascular and renal diseases, especially in the cat and dog.
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Affiliation(s)
- Marisa K Ames
- Department of Clinical Sciences, College of Veterinary Medicine, Colorado State University, Fort Collins, Colorado
| | - Clarke E Atkins
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Bertram Pitt
- Department of Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
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A proposed mechanism for the Berecek phenomenon with implications for cardiovascular reprogramming. ACTA ACUST UNITED AC 2018; 12:644-651. [PMID: 30220305 DOI: 10.1016/j.jash.2018.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/15/2018] [Indexed: 01/29/2023]
Abstract
Berecek et al reported in the 1990s that when spontaneously hypertensive rat (SHR) mating pairs were treated with captopril and the resulting pups were continued on the drug for 2 months followed by drug discontinuation, the pups did not develop full blown hypertension, and the cardiovascular structural changes associated with hypertension in SHR were mitigated. The offspring of the pups also displayed diminished hypertension and structural changes, suggesting that the drug therapy produced a heritable amelioration of the SHR phenotype. This observation is reviewed. The link between cellular renin angiotensin systems and epigenetic histone modification is explored, and a mechanism responsible for the observation is proposed. In any case, the observations of Berecek are sufficiently intriguing and biologically important to merit re-exploration and definitive explanation. Equally important is determining the role of renin angiotensin systems in epigenetic modification.
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Aerts J. Quantification of a Glucocorticoid Profile in Non-pooled Samples Is Pivotal in Stress Research Across Vertebrates. Front Endocrinol (Lausanne) 2018; 9:635. [PMID: 30405537 PMCID: PMC6206410 DOI: 10.3389/fendo.2018.00635] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/05/2018] [Indexed: 12/31/2022] Open
Abstract
Vertebrates are faced continuously with a variety of potential stressful stimuli and react by a highly conserved endocrine stress response. An immediate catecholamine mediated response increases plasma glucose levels in order to prepare the organism for the "fight or flight" reaction. In addition, in a matter of minutes after this (nor)adrenaline release, glucocorticoids, in particular cortisol or corticosterone depending on the species, are released through activation of the hypothalamic-pituitary-interrenal (HPI) axis in fish or hypothalamic-pituitary-adrenal (HPA) axis in other vertebrates. These plasma glucocorticoids are well documented and widely used as biomarker for stress across vertebrates. In order to study the role of glucocorticoids in acute and chronic stress and gain in-depth insight in the stress axis (re)activity across vertebrates, it is pivotal to pin-point the involved molecules, to understand the mechanisms of how the latter are synthesized, regulated and excreted, and to grasp their actions on a plethora of biological processes. Furthermore, in-depth knowledge on the characteristics of the tissues as well as on the analytical methodologies available for glucocorticoid quantification is needed. This manuscript is to be situated in the multi-disciplinary research topic of glucocorticoid action across vertebrates which is linked to a wide range of research domains including but not limited to biochemistry, ecology, endocrinology, ethology, histology, immunology, morphology, physiology, and toxicology, and provides a solid base for all interested in stress, in particular glucocorticoid, related research. In this framework, internationally validated confirmation methods for quantification of a glucocorticoid profile comprising: (i) the dominant hormone; (ii) its direct precursors; (iii) its endogenously present phase I metabolites; and (iv) the most abundant more polar excreted exogenous phase I metabolites in non-pooled samples are pivotal.
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Affiliation(s)
- Johan Aerts
- Stress Physiology Research Group, Faculty of Pharmaceutical Sciences, Ghent University, Ostend, Belgium
- Stress Physiology Research Group, Animal Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Ostend, Belgium
- *Correspondence: Johan Aerts
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Lang F, Leibrock C, Pelzl L, Gawaz M, Pieske B, Alesutan I, Voelkl J. Therapeutic Interference With Vascular Calcification-Lessons From Klotho-Hypomorphic Mice and Beyond. Front Endocrinol (Lausanne) 2018; 9:207. [PMID: 29780355 PMCID: PMC5945862 DOI: 10.3389/fendo.2018.00207] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/13/2018] [Indexed: 12/13/2022] Open
Abstract
Medial vascular calcification, a major pathophysiological process associated with cardiovascular disease and mortality, involves osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells (VSMCs). In chronic kidney disease (CKD), osteo-/chondrogenic transdifferentiation of VSMCs and, thus, vascular calcification is mainly driven by hyperphosphatemia, resulting from impaired elimination of phosphate by the diseased kidneys. Hyperphosphatemia with subsequent vascular calcification is a hallmark of klotho-hypomorphic mice, which are characterized by rapid development of multiple age-related disorders and early death. In those animals, hyperphosphatemia results from unrestrained formation of 1,25(OH)2D3 with subsequent retention of calcium and phosphate. Analysis of klotho-hypomorphic mice and mice with vitamin D3 overload uncovered several pathophysiological mechanisms participating in the orchestration of vascular calcification and several therapeutic opportunities to delay or even halt vascular calcification. The present brief review addresses the beneficial effects of bicarbonate, carbonic anhydrase inhibition, magnesium supplementation, mineralocorticoid receptor (MR) blockage, and ammonium salts. The case is made that bicarbonate is mainly effective by decreasing intestinal phosphate absorption, and that carbonic anhydrase inhibition leads to metabolic acidosis, which counteracts calcium-phosphate precipitation and VSMC transdifferentiation. Magnesium supplementation, MR blockage and ammonium salts are mainly effective by interference with osteo-/chondrogenic signaling in VSMCs. It should be pointed out that the, by far, most efficient substances are ammonium salts, which may virtually prevent vascular calcification. Future research will probably uncover further therapeutic options and, most importantly, reveal whether these observations in mice can be translated into treatment of patients suffering from vascular calcification, such as patients with CKD.
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Affiliation(s)
- Florian Lang
- Department of Physiology I, Eberhard Karls-University, Tübingen, Germany
- *Correspondence: Florian Lang,
| | - Christina Leibrock
- Department of Physiology I, Eberhard Karls-University, Tübingen, Germany
- Fresenius Kabi Deutschland GmbH, Bad Homburg, Germany
| | - Lisann Pelzl
- Department of Physiology I, Eberhard Karls-University, Tübingen, Germany
| | - Meinrad Gawaz
- Department of Internal Medicine III, Eberhard Karls-University, Tübingen, Germany
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité-Universität Medizin Berlin, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
- Partner Site Berlin, German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Ioana Alesutan
- Department of Internal Medicine and Cardiology, Charité-Universität Medizin Berlin, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
- Partner Site Berlin, German Centre for Cardiovascular Research (DZHK), Berlin, Germany
| | - Jakob Voelkl
- Department of Internal Medicine and Cardiology, Charité-Universität Medizin Berlin, Berlin, Germany
- Partner Site Berlin, German Centre for Cardiovascular Research (DZHK), Berlin, Germany
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Beladiya JV, Chaudagar KK, Mehta AA. A protective role of Gαq-RGS2 loop activator on streptozotocin induced diabetic complications in rats: An independent on elevated serum glucose level modulation. Eur J Pharmacol 2018; 818:141-147. [DOI: 10.1016/j.ejphar.2017.10.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 10/18/2022]
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Park EJ, Jung HJ, Choi HJ, Cho JI, Park HJ, Kwon TH. miR-34c-5p and CaMKII are involved in aldosterone-induced fibrosis in kidney collecting duct cells. Am J Physiol Renal Physiol 2017; 314:F329-F342. [PMID: 29070573 DOI: 10.1152/ajprenal.00358.2017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mineralocorticoids trigger a profibrotic process in the kidney. In mouse cortical collecting duct cells, the present study addressed two main questions: 1) what are microRNAs (miRNAs) and their target genes that are changed by aldosterone? and 2) what do miRNAs, in response to aldosterone, regulate regarding signaling pathways related to fibrosis? A microarray chip assay was done in cells in the absence or presence of aldosterone treatment (10-6 M; 3 days). The candidate miRNAs were identified by the criteria of >30% of fold change among the significantly changed miRNAs ( P < 0.05). Twenty-nine miRNAs were upregulated (>1.3-fold), and 27 miRNAs were downregulated (<0.7-fold). Putative target genes of identified miRNAs were associated with 74 Kyoto Encyclopedia of Genes and Genomes pathways. Among them, the wingless-related integration site (Wnt) signaling pathway was highly ranked, where 15 mature miRNAs were observed. These miRNAs were further analyzed by real-time quantitative PCR, and among them, miR-130b-3p, miR-34c-5p, and miR-146a-5p were selected. Through the identification of putative target genes of these three miRNAs, mRNA and protein expression of the Ca2+/calmodulin-dependent protein kinase type II β-chain ( Camk2b) gene (a target gene of miR-34c-5p) were found to be increased significantly in aldosterone-treated cells, where fibronectin (FN) and α-smooth muscle actin were induced. When CaMKIIβ small interfering RNA or the miR-34c-5p mimic was transfected, aldosterone-induced FN expression was significantly attenuated, along with reduced CaMKIIβ protein expression. A luciferase reporter assay revealed a decrease of CaMKIIβ translation in cells transfected with miRNA mimics of miR-34c-5p. In conclusion, aldosterone-induced downregulation of miR-34c-5p in the Wnt signaling pathway and a consequent increase of CaMKIIβ expression are likely to be involved in aldosterone-induced fibrosis.
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Affiliation(s)
- Eui-Jung Park
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea.,BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Taegu, Korea
| | - Hyun Jun Jung
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea.,Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Hyo-Jung Choi
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea
| | - Jeong-In Cho
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea.,BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Taegu, Korea
| | - Hye-Jeong Park
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea.,BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Taegu, Korea
| | - Tae-Hwan Kwon
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Taegu, Korea.,BK21 Plus KNU Biomedical Convergence Program, Department of Biomedical Science, School of Medicine, Kyungpook National University, Taegu, Korea
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17
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Abstract
PURPOSE OF REVIEW The purpose of this study was to summarize recent findings about cardiovascular benefits and safety of aldosterone blockade in patients with end-stage renal disease (ESRD). RECENT FINDINGS It is now well recognized that aldosterone's deleterious cardiovascular impact is not limited to its pressor effect arising from an increase in sodium reabsorption in the kidneys. Aldosterone has also been shown to increase blood pressure by a direct activation of the sympathetic nervous system, to cause endothelial and vascular smooth muscle cell dysfunction, myocardial remodeling and fibrosis, and to have pro-arrhythmogenic actions in the heart. These unconventional extra-renal effects of aldosterone make its blockade feasible and potentially beneficial for patients with ESRD. Accumulating data support the idea that aldosterone antagonism leads to a better blood pressure control, reduction in left ventricular (LV) mass, improved LV function, and reduced all-cause and cardiovascular mortality in ESRD patients. Reassuringly, rates of major adverse events, especially, significant hyperkalemia-the most feared adverse consequence-were low with careful patient selection and monitoring.
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Affiliation(s)
- Radmila Lyubarova
- Division of Cardiology, Department of Medicine, Albany Medical College, Albany, NY, USA
| | - Elvira O Gosmanova
- Nephrology Section, Stratton VA Medical Center, 113 Holland Ave, Albany, NY, 12208, USA.
- Division of Nephrology and Hypertension, Department of Medicine, Albany Medical College, Albany, NY, USA.
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18
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Re RN. A Pathogenic Mechanism Potentially Operative in Multiple Progressive Diseases and Its Therapeutic Implications. J Clin Pharmacol 2017; 57:1507-1518. [DOI: 10.1002/jcph.997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Richard N. Re
- Division of Academics-Research; Ochsner Clinic Foundation; New Orleans LA USA
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19
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Alesutan I, Voelkl J, Feger M, Kratschmar DV, Castor T, Mia S, Sacherer M, Viereck R, Borst O, Leibrock C, Gawaz M, Kuro-O M, Pilz S, Tomaschitz A, Odermatt A, Pieske B, Wagner CA, Lang F. Involvement Of Vascular Aldosterone Synthase In Phosphate-Induced Osteogenic Transformation Of Vascular Smooth Muscle Cells. Sci Rep 2017; 7:2059. [PMID: 28515448 PMCID: PMC5435689 DOI: 10.1038/s41598-017-01882-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/04/2017] [Indexed: 02/07/2023] Open
Abstract
Vascular calcification resulting from hyperphosphatemia is a major determinant of mortality in chronic kidney disease (CKD). Vascular calcification is driven by aldosterone-sensitive osteogenic transformation of vascular smooth muscle cells (VSMCs). We show that even in absence of exogenous aldosterone, silencing and pharmacological inhibition (spironolactone, eplerenone) of the mineralocorticoid receptor (MR) ameliorated phosphate-induced osteo-/chondrogenic transformation of primary human aortic smooth muscle cells (HAoSMCs). High phosphate concentrations up-regulated aldosterone synthase (CYP11B2) expression in HAoSMCs. Silencing and deficiency of CYP11B2 in VSMCs ameliorated phosphate-induced osteogenic reprogramming and calcification. Phosphate treatment was followed by nuclear export of APEX1, a CYP11B2 transcriptional repressor. APEX1 silencing up-regulated CYP11B2 expression and stimulated osteo-/chondrogenic transformation. APEX1 overexpression blunted the phosphate-induced osteo-/chondrogenic transformation and calcification of HAoSMCs. Cyp11b2 expression was higher in aortic tissue of hyperphosphatemic klotho-hypomorphic (kl/kl) mice than in wild-type mice. In adrenalectomized kl/kl mice, spironolactone treatment still significantly ameliorated aortic osteoinductive reprogramming. Our findings suggest that VSMCs express aldosterone synthase, which is up-regulated by phosphate-induced disruption of APEX1-dependent gene suppression. Vascular CYP11B2 may contribute to stimulation of VSMCs osteo-/chondrogenic transformation during hyperphosphatemia.
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Affiliation(s)
- Ioana Alesutan
- Department of Physiology, University of Tübingen, Tübingen, Germany
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Jakob Voelkl
- Department of Physiology, University of Tübingen, Tübingen, Germany
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Berlin, Germany
| | - Martina Feger
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - Denise V Kratschmar
- Department of Pharmaceutical Sciences, and the National Center for Excellence in Research NCCR Kidney.CH, University of Basel, Basel, Switzerland
| | - Tatsiana Castor
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - Sobuj Mia
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - Michael Sacherer
- Div. of Cardiology, Medical University of Graz and Ludwig Boltzmann Institute for Translational Heart Failure Research, Graz, Austria
| | - Robert Viereck
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - Oliver Borst
- Department of Physiology, University of Tübingen, Tübingen, Germany
- Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen, Germany
| | | | - Meinrad Gawaz
- Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen, Germany
| | - Makoto Kuro-O
- Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University of Graz, Graz, Austria
| | - Andreas Tomaschitz
- Div. of Cardiology, Medical University of Graz and Ludwig Boltzmann Institute for Translational Heart Failure Research, Graz, Austria
- Bad Gleichenberg Clinic, Bad Gleichenberg, Austria
| | - Alex Odermatt
- Department of Pharmaceutical Sciences, and the National Center for Excellence in Research NCCR Kidney.CH, University of Basel, Basel, Switzerland
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
- Department of Cardiology, University of Graz, Graz, Austria; Department of Internal Medicine and Cardiology, German Heart Center Berlin (DHZB), Berlin, Germany
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, and the National Center for Excellence in Research NCCR Kidney, Zurich, Switzerland
| | - Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany.
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20
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Molina-Jijón E, Rodríguez-Muñoz R, González-Ramírez R, Namorado-Tónix C, Pedraza-Chaverri J, Reyes JL. Aldosterone signaling regulates the over-expression of claudin-4 and -8 at the distal nephron from type 1 diabetic rats. PLoS One 2017; 12:e0177362. [PMID: 28493961 PMCID: PMC5426686 DOI: 10.1371/journal.pone.0177362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/17/2017] [Indexed: 12/19/2022] Open
Abstract
Hyperglycemia in diabetes alters tight junction (TJ) proteins in the kidney. We evaluated the participation of aldosterone (ALD), and the effect of spironolactone (SPL), a mineralocorticoid receptor antagonist, on the expressions of claudin-2, -4, -5 and -8, and occludin in glomeruli, proximal and distal tubules isolated from diabetic rats. Type 1 diabetes was induced in female Wistar rats by a single tail vein injection of streptozotocin (STZ), and SPL was administrated daily by gavage, from days 3–21. Twenty-one days after STZ injection the rats were sacrificed. In diabetic rats, the serum ALD levels were increased, and SPL-treatment did not have effect on these levels or in hyperglycemia, however, proteinuria decreased in SPL-treated diabetic rats. Glomerular damage, evaluated by nephrin and Wilm’s tumor 1 (WT1) protein expressions, and proximal tubular damage, evaluated by kidney injury molecule 1 (Kim-1) and heat shock protein 72 kDa (Hsp72) expressions, were ameliorated by SPL. Also, SPL prevented decrement in claudin-5 in glomeruli, and claudin-2 and occludin in proximal tubules by decreasing oxidative stress, evaluated by superoxide anion (O2●―) production, and oxidative stress markers. In distal tubules, SPL ameliorated increase in mRNA, protein expression, and phosphorylation in threonine residues of claudin-4 and -8, through a serum and glucocorticoid-induced kinase 1 (SGK1), and with-no-lysine kinase 4 (WNK4) signaling pathway. In conclusion, this is the first study that demonstrates that ALD modulates the expression of renal TJ proteins in diabetes, and that the blockade of its actions with SPL, may be a promising therapeutic strategy to prevent alterations of TJ proteins in diabetic nephropathy.
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MESH Headings
- Aldosterone/metabolism
- Animals
- Claudin-4/metabolism
- Claudins/metabolism
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/complications
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Female
- Hyperglycemia/blood
- Hyperglycemia/drug therapy
- Hyperglycemia/prevention & control
- Immediate-Early Proteins/metabolism
- Kidney Glomerulus/drug effects
- Kidney Glomerulus/pathology
- Kidney Tubules/drug effects
- Kidney Tubules/pathology
- Models, Biological
- Natriuresis/drug effects
- Nephrons/metabolism
- Oxidative Stress/drug effects
- Phosphorylation/drug effects
- Potassium/blood
- Protein Serine-Threonine Kinases/metabolism
- Proteinuria/blood
- Proteinuria/complications
- Proteinuria/drug therapy
- Proteinuria/prevention & control
- Rats, Wistar
- Signal Transduction/drug effects
- Spironolactone/pharmacology
- Spironolactone/therapeutic use
- Tight Junctions/drug effects
- Tight Junctions/metabolism
- Weight Loss/drug effects
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Affiliation(s)
- Eduardo Molina-Jijón
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
- Departamento de Biociencias e Ingeniería, Centro Interdisciplinario de Investigaciones y Estudios sobre el Medio Ambiente y Desarrollo del Instituto Politécnico Nacional (CIIEMAD-IPN), Mexico City, México
| | - Rafael Rodríguez-Muñoz
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
| | - Ricardo González-Ramírez
- Department of Molecular Biology and Histocompatibility, Dr. Manuel Gea González, General Hospital, Mexico City, México
| | - Carmen Namorado-Tónix
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
| | - José Pedraza-Chaverri
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, México
| | - Jose L. Reyes
- Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV-IPN), Mexico City, México
- * E-mail:
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21
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Bai J, Chow BKC. Secretin is involved in sodium conservation through the renin-angiotensin-aldosterone system. FASEB J 2017; 31:1689-1697. [PMID: 28082350 DOI: 10.1096/fj.201600911r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 01/03/2017] [Indexed: 01/22/2023]
Abstract
Secretin (SCT) and its receptor (SCTR) are important in fluid regulation at multiple levels via the modulation of expression and translocation of renal aquaporin 2 and functions of central angiotensin II (ANGII). The functional interaction of SCT with peripheral ANGII, however, remains unknown. As the ANGII-aldosterone axis dominates the regulation of renal epithelial sodium channel (ENaC) function, we therefore tested whether SCT/SCTR can regulate sodium homeostasis via the renin-angiotensin-aldosterone system. SCTR-knockout (SCTR-/-) mice showed impaired aldosterone synthase (CYP11B2) expression and, consequently, aldosterone release upon intraperitoneal injection of ANGII. Endogenous ANGII production induced by dietary sodium restriction was higher in SCTR-/- than in C57BL/6N [wild-type (WT)] mice, but CYP11B2 and aldosterone synthesis were not elevated. Reduced accumulation of cholesteryl ester-the precursor of aldosterone-was observed in adrenal glands of SCTR-/- mice that were fed a low-sodium diet. Absence of SCTR resulted in elevated basal transcript levels of adrenal CYP11B2 and renal ENaCs. Although transcript and protein levels of ENaCs were similar in WT and SCTR-/- mice under sodium restriction, ENaCs in SCTR-/- mice were less sensitive to amiloride hydrochloride. In summary, the SCT/SCTR axis is involved in aldosterone precursor uptake, and the knockout of SCTR results in defective aldosterone biosynthesis/release and altered sensitivity of ENaCs to amiloride.-Bai, J., Chow, B. K. C. Secretin is involved in sodium conservation through the renin-angiotensin-aldosterone system.
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Affiliation(s)
- Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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22
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Abstract
Heart failure and chronic renal diseases are usually progressive and only partially amenable to therapy. These disorders can be the sequelae of hypertension or worsened by hypertension. They are associated with the tissue up-regulation of multiple peptides, many of which are capable of acting within the cell interior. This article proposes that these peptides, intracrines, can form self-sustaining regulatory loops that can spread through heart or kidney, producing progressive disease. Moreover, mineralocorticoid activation seems capable of amplifying some of these peptide networks. This view suggests an expanded explanation of the pathogenesis of progressive cardiorenal disease and suggests new approaches to treatment.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, Division of Research, 1514 Jefferson Highway, New Orleans, LA 70121, USA.
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23
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Xu C, Fang H, Zhou L, Lu A, Yang T. High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells. Am J Physiol Cell Physiol 2016; 311:C686-C695. [PMID: 27534754 PMCID: PMC5129751 DOI: 10.1152/ajpcell.00128.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/12/2016] [Indexed: 11/22/2022]
Abstract
(Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release.
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Affiliation(s)
- Chuanming Xu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; and
| | - Hui Fang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; and
| | - Li Zhou
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; and
| | - Aihua Lu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; and
| | - Tianxin Yang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; and .,Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah
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24
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Xu C, Lu A, Wang H, Fang H, Zhou L, Sun P, Yang T. (Pro)Renin receptor regulates potassium homeostasis through a local mechanism. Am J Physiol Renal Physiol 2016; 313:F641-F656. [PMID: 27440776 DOI: 10.1152/ajprenal.00043.2016] [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] [Received: 01/22/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022] Open
Abstract
(Pro)renin receptor (PRR) is highly expressed in the distal nephron, but it has an unclear functional implication. The present study was conducted to explore a potential role of renal PRR during high K+ (HK) loading. In normal Sprague-Dawley rats, a 1-wk HK intake increased renal expression of full-length PRR and urinary excretion of soluble PRR (sPRR). Administration of PRO20, a decoy peptide antagonist of PRR, in K+-loaded animals elevated plasma K+ level and decreased urinary K+ excretion, accompanied with suppressed urinary aldosterone excretion and intrarenal aldosterone levels. HK downregulated Na+-Cl- cotransporter (NCC) expression but upregulated CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2), renal outer medullary K+ channel (ROMK), calcium-activated potassium channel subunit α1 (α-BK), α-Na+-K+-ATPase (α-NKA), and epithelial Na+ channel subunit β (β-ENaC), all of which were blunted by PRO20. After HK loading was completed, urinary, but not plasma renin, was upregulated, which was blunted by PRO20. The same experiments that were performed using adrenalectomized (ADX) rats yielded similar results. Interestingly, spironolactone treatment in HK-loaded ADX rats attenuated kaliuresis but promoted natriuresis, which was associated with the suppressed responses of β-ENaC, α-NKA, ROMK, and α-BK protein expression. Taken together, we discovered a novel role of renal PRR in regulation of K+ homeostasis through a local mechanism involving intrarenal renin-angiotensin-aldosterone system and coordinated regulation of membrane Na+- and K+-transporting proteins.
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Affiliation(s)
- Chuanming Xu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Aihua Lu
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hong Wang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Hui Fang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Li Zhou
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China
| | - Peng Sun
- Anesthesiology, Sun Yat-sen University Cancer Center, Guangzhou, China; and
| | - Tianxin Yang
- Institute of Hypertension, Sun Yat-sen University School of Medicine, Guangzhou, China; .,Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, Utah
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25
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Bai JJ, Tan CD, Chow BKC. Secretin, at the hub of water-salt homeostasis. Am J Physiol Renal Physiol 2016; 312:F852-F860. [PMID: 27279485 DOI: 10.1152/ajprenal.00191.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/01/2016] [Indexed: 01/13/2023] Open
Abstract
Water and salt metabolism are tightly regulated processes. Maintaining this milieu intérieur within narrow limits is critical for normal physiological processes to take place. Disturbances to this balance can result in disease and even death. Some of the better-characterized regulators of water and salt homeostasis include angiotensin II, aldosterone, arginine vasopressin, and oxytocin. Although secretin (SCT) was first described >100 years ago, little is known about the role of this classic gastrointestinal hormone in the maintenance of water-salt homeostasis. In recent years, increasing body of evidence suggested that SCT and its receptor play important roles in the central nervous system and kidney to ensure that the mammalian extracellular fluid osmolarity is kept within a healthy range. In this review, we focus on recent advances in our understanding of the molecular, cellular, and network mechanisms by which SCT and its receptor mediate the control of osmotic homeostasis. Implications of hormonal cross talk and receptor-receptor interaction are highlighted.
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Affiliation(s)
- Jenny Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Chong Da Tan
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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26
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Bernardi S, Michelli A, Zuolo G, Candido R, Fabris B. Update on RAAS Modulation for the Treatment of Diabetic Cardiovascular Disease. J Diabetes Res 2016; 2016:8917578. [PMID: 27652272 PMCID: PMC5019930 DOI: 10.1155/2016/8917578] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/27/2016] [Indexed: 02/07/2023] Open
Abstract
Since the advent of insulin, the improvements in diabetes detection and the therapies to treat hyperglycemia have reduced the mortality of acute metabolic emergencies, such that today chronic complications are the major cause of morbidity and mortality among diabetic patients. More than half of the mortality that is seen in the diabetic population can be ascribed to cardiovascular disease (CVD), which includes not only myocardial infarction due to premature atherosclerosis but also diabetic cardiomyopathy. The importance of renin-angiotensin-aldosterone system (RAAS) antagonism in the prevention of diabetic CVD has demonstrated the key role that the RAAS plays in diabetic CVD onset and development. Today, ACE inhibitors and angiotensin II receptor blockers represent the first line therapy for primary and secondary CVD prevention in patients with diabetes. Recent research has uncovered new dimensions of the RAAS and, therefore, new potential therapeutic targets against diabetic CVD. Here we describe the timeline of paradigm shifts in RAAS understanding, how diabetes modifies the RAAS, and what new parts of the RAAS pathway could be targeted in order to achieve RAAS modulation against diabetic CVD.
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Affiliation(s)
- Stella Bernardi
- Department of Medical Sciences, University of Trieste, Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
- Division of Medicina Clinica, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
- *Stella Bernardi:
| | - Andrea Michelli
- Department of Medical Sciences, University of Trieste, Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
| | - Giulia Zuolo
- Department of Medical Sciences, University of Trieste, Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
| | - Riccardo Candido
- Diabetes Centre, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Via Puccini, 34100 Trieste, Italy
| | - Bruno Fabris
- Department of Medical Sciences, University of Trieste, Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
- Division of Medicina Clinica, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Cattinara Teaching Hospital, Strada di Fiume, 34100 Trieste, Italy
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27
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Epstein M. Reduction of cardiovascular risk in chronic kidney disease by mineralocorticoid receptor antagonism. Lancet Diabetes Endocrinol 2015; 3:993-1003. [PMID: 26429402 DOI: 10.1016/s2213-8587(15)00289-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 12/24/2022]
Abstract
Cardiovascular disease is the leading cause of death and morbidity in people with chronic kidney disease, but there are few evidence-based treatments for reducing cardiovascular events in these patients. The failure of novel drug candidates to delay progression to end-stage renal disease and limit or abrogate cardiovascular morbidity and mortality has led to increased interest in a mineralocorticoid receptor (MR) antagonist-based treatment model to reduce cardiovascular risk in patients with chronic kidney disease and end-stage renal disease. Aldosterone concentrations and MR signalling are associated with an enhanced risk of cardiovascular injury and the incidence of sudden death, and MR blockade decreases the risk of cardiovascular events and sudden death in patients with reduced glomerular filtration rate. Since evidence from clinical trials shows that treatment with MR antagonists confers a morbidity and mortality advantage for patients with cardiovascular disorders, similar benefits might also accrue in patients with chronic kidney disease. Large prospective trials are urgently needed to answer this question. In this Review, I argue that despite differences in the pathophysiology and clinical features of cardiovascular disease in patients with and without chronic kidney disease, MR antagonists could provide cardiovascular benefit in patients with chronic kidney disease.
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Affiliation(s)
- Murray Epstein
- Division of Nephrology and Hypertension, University of Miami, Leonard M Miller School of Medicine, Miami, FL, USA.
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A mechanism for mineralocortcoid participation in renal disease and heart failure. ACTA ACUST UNITED AC 2015; 9:586-91. [DOI: 10.1016/j.jash.2015.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 04/22/2015] [Accepted: 05/02/2015] [Indexed: 12/21/2022]
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Wesson DE, Jo CH, Simoni J. Angiotensin II-mediated GFR decline in subtotal nephrectomy is due to acid retention associated with reduced GFR. Nephrol Dial Transplant 2014; 30:762-70. [PMID: 25527741 DOI: 10.1093/ndt/gfu388] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 11/22/2014] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Angiotensin II (AII) mediates glomerular filtration rate (GFR) decline in animals with subtotal nephrectomy (Nx), but the mechanisms for increased AII activity are unknown. Because reduced GFR of Nx is associated with acid (H(+)) retention that increases kidney AII, AII-mediated GFR decline might be induced by H(+) retention. METHODS We measured GFR and kidney microdialyzate H(+) and AII content in Sham and 2/3 Nx rats in response to amelioration of H(+) retention with dietary NaHCO3, to AII receptor antagonism and to both. RESULTS GFR was lower in Nx than that in Sham. Nx but not Sham GFR was lower at Week 24 than that at Week 1. Despite no differences in plasma acid-base parameters or urine net acid excretion, kidney H(+) content was higher in Nx than that in Sham, consistent with H(+) retention. Plasma and kidney microdialyzate AII were higher in Nx than that in Sham and dietary NaHCO3 reduced each in Nx but not in Sham. AII receptor antagonism was associated with higher Week 24 GFR in Nx with H(+) retention but not in Sham or in Nx in which H(+) retention had been corrected with dietary NaHCO3. Week 24 GFR after dietary NaHCO3 was higher than after AII receptor antagonism. Week 24 GFR was not different after adding AII receptor antagonism to dietary NaHCO3. CONCLUSIONS AII-mediated GFR decline in 2/3 Nx was induced by H(+) retention and its amelioration with dietary HCO3 conserved GFR better than AII receptor antagonism in this CKD model. H(+) retention might induce AII-mediated GFR decline in patients with reduced GFR, even without metabolic acidosis.
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Affiliation(s)
- Donald E Wesson
- Department of Internal Medicine, Baylor Scott and White Health, Temple, TX, USA Texas A&M Health Sciences Center College of Medicine, Temple, TX, USA
| | - Chan-Hee Jo
- Department of Biostatistics, Baylor Scott and White Health, Temple, TX, USA
| | - Jan Simoni
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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Sun QL, Li M, Rui HL, Chen YP. Inhibition of local aldosterone by eplerenone reduces renal structural damage in a novel model of chronic cyclosporine A nephrotoxicity. J Renin Angiotensin Aldosterone Syst 2014; 16:301-10. [PMID: 25500744 DOI: 10.1177/1470320314561248] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 10/14/2014] [Indexed: 11/16/2022] Open
Affiliation(s)
- Qiao-Ling Sun
- Department of Nephrology, Qilu Hospital, Shandong University, China
| | - Meng Li
- Department of Neurosurgery, Qianfoshan Hospital, Shandong University, China
| | - Hong-Liang Rui
- Department of Nephrology, Beijing An Zhen Hospital, Capital Medical University, China
| | - Yi-Pu Chen
- Department of Nephrology, Beijing An Zhen Hospital, Capital Medical University, China
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Todkar A, Picard N, Loffing-Cueni D, Sorensen MV, Mihailova M, Nesterov V, Makhanova N, Korbmacher C, Wagner CA, Loffing J. Mechanisms of renal control of potassium homeostasis in complete aldosterone deficiency. J Am Soc Nephrol 2014; 26:425-38. [PMID: 25071088 DOI: 10.1681/asn.2013111156] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Aldosterone-independent mechanisms may contribute to K(+) homeostasis. We studied aldosterone synthase knockout (AS(-/-)) mice to define renal control mechanisms of K(+) homeostasis in complete aldosterone deficiency. AS(-/-) mice were normokalemic and tolerated a physiologic dietary K(+) load (2% K(+), 2 days) without signs of illness, except some degree of polyuria. With supraphysiologic K(+) intake (5% K(+)), AS(-/-) mice decompensated and became hyperkalemic. High-K(+) diets induced upregulation of the renal outer medullary K(+) channel in AS(-/-) mice, whereas upregulation of the epithelial sodium channel (ENaC) sufficient to increase the electrochemical driving force for K(+) excretion was detected only with a 2% K(+) diet. Phosphorylation of the thiazide-sensitive NaCl cotransporter was consistently lower in AS(-/-) mice than in AS(+/+) mice and was downregulated in mice of both genotypes in response to increased K(+) intake. Inhibition of the angiotensin II type 1 receptor reduced renal creatinine clearance and apical ENaC localization, and caused severe hyperkalemia in AS(-/-) mice. In contrast with the kidney, the distal colon of AS(-/-) mice did not respond to dietary K(+) loading, as indicated by Ussing-type chamber experiments. Thus, renal adaptation to a physiologic, but not supraphysiologic, K(+) load can be achieved in aldosterone deficiency by aldosterone-independent activation of the renal outer medullary K(+) channel and ENaC, to which angiotensin II may contribute. Enhanced urinary flow and reduced activity of the thiazide-sensitive NaCl cotransporter may support renal adaptation by activation of flow-dependent K(+) secretion and increased intratubular availability of Na(+) that can be reabsorbed in exchange for K(+) secreted.
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Affiliation(s)
- Abhijeet Todkar
- Institutes of Anatomy and Physiology, and Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | | | | | | | | | - Viatcheslav Nesterov
- Institute for Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Natalia Makhanova
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Christoph Korbmacher
- Institute for Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany; and
| | - Carsten A Wagner
- Physiology, and Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Johannes Loffing
- Institutes of Anatomy and Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland;
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Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate. Kidney Int 2014; 86:1031-8. [PMID: 24694986 DOI: 10.1038/ki.2014.83] [Citation(s) in RCA: 263] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 01/01/2014] [Accepted: 02/06/2014] [Indexed: 12/28/2022]
Abstract
Alkali therapy of metabolic acidosis in patients with chronic kidney disease (CKD) with plasma total CO2 (TCO2) below 22 mmol/l per KDOQI guidelines appears to preserve estimated glomerular filtration rate (eGFR). Since angiotensin II mediates GFR decline in partial nephrectomy models of CKD and even mild metabolic acidosis increases kidney angiotensin II in animals, alkali treatment of CKD-related metabolic acidosis in patients with plasma TCO2 over 22 mmol/l might preserve GFR through reduced kidney angiotensin II. To test this, we randomized 108 patients with stage 3 CKD and plasma TCO2 22-24 mmol/l to Usual Care or interventions designed to reduce dietary acid by 50% using sodium bicarbonate or base-producing fruits and vegetables. All were treated to achieve a systolic blood pressure below 130 mm Hg with regimens including angiotensin converting enzyme inhibition and followed for 3 years. Plasma TCO2 decreased in Usual Care but increased with bicarbonate or fruits and vegetables. By contrast, urine excretion of angiotensinogen, an index of kidney angiotensin II, increased in Usual Care but decreased with bicarbonate or fruits and vegetables. Creatinine-calculated and cystatin C-calculated eGFR decreased in all groups, but loss was less at 3 years with bicarbonate or fruits and vegetables than Usual Care. Thus, dietary alkali treatment of metabolic acidosis in CKD that is less severe than that for which KDOQI recommends therapy reduces kidney angiotensin II activity and preserves eGFR.
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Li C, Siragy HM. High glucose induces podocyte injury via enhanced (pro)renin receptor-Wnt-β-catenin-snail signaling pathway. PLoS One 2014; 9:e89233. [PMID: 24533170 PMCID: PMC3923071 DOI: 10.1371/journal.pone.0089233] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/17/2014] [Indexed: 01/04/2023] Open
Abstract
(Pro)renin receptor (PRR) expression is upregulated in diabetes. We hypothesized that PRR contributes to podocyte injury via activation of Wnt-β-catenin-snail signaling pathway. Mouse podocytes were cultured in normal (5 mM) or high (25 mM) D-glucose for 3 days. Compared to normal glucose, high glucose significantly decreased mRNA and protein expressions of podocin and nephrin, and increased mRNA and protein expressions of PRR, Wnt3a, β-catenin, and snail, respectively. Confocal microscopy studies showed significant reduction in expression and reorganization of podocyte cytoskeleton protein, F-actin, in response to high glucose. Transwell functional permeability studies demonstrated significant increase in albumin flux through podocytes monolayer with high glucose. Cells treated with high glucose and PRR siRNA demonstrated significantly attenuated mRNA and protein expressions of PRR, Wnt3a, β-catenin, and snail; enhanced expressions of podocin mRNA and protein, improved expression and reorganization of F-actin, and reduced transwell albumin flux. We conclude that high glucose induces podocyte injury via PRR-Wnt-β-catenin-snail signaling pathway.
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Affiliation(s)
- Caixia Li
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Helmy M. Siragy
- Division of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, Virginia, United States of America
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Wada T, Miyashita Y, Sasaki M, Aruga Y, Nakamura Y, Ishii Y, Sasahara M, Kanasaki K, Kitada M, Koya D, Shimano H, Tsuneki H, Sasaoka T. Eplerenone ameliorates the phenotypes of metabolic syndrome with NASH in liver-specific SREBP-1c Tg mice fed high-fat and high-fructose diet. Am J Physiol Endocrinol Metab 2013; 305:E1415-25. [PMID: 24129399 DOI: 10.1152/ajpendo.00419.2013] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Because the renin-angiotensin-aldosterone system has been implicated in the development of insulin resistance and promotion of fibrosis in some tissues, such as the vasculature, we examined the effect of eplerenone, a selective mineralocorticoid receptor (MR) antagonist, on nonalcoholic steatohepatitis (NASH) and metabolic phenotypes in a mouse model reflecting metabolic syndrome in humans. We adopted liver-specific transgenic (Tg) mice overexpressing the active form of sterol response element binding protein-1c (SREBP-1c) fed a high-fat and fructose diet (HFFD) as the animal model in the present study. When wild-type (WT) C57BL/6 and liver-specific SREBP-1c Tg mice grew while being fed HFFD for 12 wk, body weight and epididymal fat weight increased in both groups with an elevation in blood pressure and dyslipidemia. Glucose intolerance and insulin resistance were also observed. Adipose tissue hypertrophy and macrophage infiltration with crown-like structure formation were also noted in mice fed HFFD. Interestingly, the changes noted in both genotypes fed HFFD were significantly ameliorated with eplerenone. HFFD-fed Tg mice exhibited the histological features of NASH in the liver, including macrovesicular steatosis and fibrosis, whereas HFFD-fed WT mice had hepatic steatosis without apparent fibrotic changes. Eplerenone effectively ameliorated these histological abnormalities. Moreover, the direct suppressive effects of eplerenone on lipopolysaccharide-induced TNFα production in the presence and absence of aldosterone were observed in primary-cultured Kupffer cells and bone marrow-derived macrophages. These results indicated that eplerenone prevented the development of NASH and metabolic abnormalities in mice by inhibiting inflammatory responses in both Kupffer cells and macrophages.
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Ritz E, Tomaschitz A. Aldosterone and the kidney: a rapidly moving frontier (an update). Nephrol Dial Transplant 2013; 29:2012-9. [PMID: 24194611 DOI: 10.1093/ndt/gft035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Beyond the classical effect of aldosterone on sodium reabsorption in the distal nephron, the spectrum of aldosterone-induced effects on the kidney (and the cardiovascular system) continues to expand at a rapid pace. Blockade of this system has become an attractive target for intervention. Major contributions have been reported in the past 2-3 years. By necessity this brief summary addresses only some of the emerging issues of nephrological relevance. In this fast moving field, we try to give a concise discussion of papers with potential nephrological relevance in the past 2-3 years.
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Affiliation(s)
- Eberhard Ritz
- Nierenzentrum, Im Neuenheimer Feld 162, Heidelberg, Germany
| | - Andreas Tomaschitz
- Department of Cardiology, Medical University Graz, Graz, Austria Specialist Clinic for Rehabilitation PV Bad Aussee, Bad Aussee, Austria
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36
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Rapid induction of aldosterone synthesis in cultured neonatal rat cardiomyocytes under high glucose conditions. BIOMED RESEARCH INTERNATIONAL 2013; 2013:161396. [PMID: 24288663 PMCID: PMC3830858 DOI: 10.1155/2013/161396] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/22/2013] [Indexed: 11/17/2022]
Abstract
In addition to classical adrenal cortical biosynthetic pathway, there is increasing evidence that aldosterone is produced in extra-adrenal tissues. Although we previously reported aldosterone production in the heart, the concept of cardiac aldosterone synthesis remains controversial. This is partly due to lack of established experimental models representing aldosterone synthase (CYP11B2) expression in robustly reproducible fashion. We herein investigated suitable conditions in neonatal rat cardiomyocytes (NRCMs) culture system producing CYP11B2 with considerable efficacy. NRCMs were cultured with various glucose doses for 2-24 hours. CYP11B2 mRNA expression and aldosterone concentrations secreted from NRCMs were determined using real-time PCR and enzyme immunoassay, respectively. We found that suitable conditions for CYP11B2 induction included four-hour incubation with high glucose conditions. Under these particular conditions, CYP11B2 expression, in accordance with aldosterone secretion, was significantly increased compared to those observed in the cells cultured under standard-glucose condition. Angiotensin II receptor blocker partially inhibited this CYP11B2 induction, suggesting that there is local renin-angiotensin-aldosterone system activation under high glucose conditions. The suitable conditions for CYP11B2 induction in NRCMs culture system are now clarified: high-glucose conditions with relatively brief period of culture promote CYP11B2 expression in cardiomyocytes. The current system will help to accelerate further progress in research on cardiac tissue aldosterone synthesis.
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Lumbers ER, Pringle KG, Wang Y, Gibson KJ. The renin-angiotensin system from conception to old age: the good, the bad and the ugly. Clin Exp Pharmacol Physiol 2013; 40:743-52. [DOI: 10.1111/1440-1681.12098] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 04/08/2013] [Accepted: 04/12/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Eugenie R Lumbers
- School of Biomedical Sciences and Pharmacy; Hunter Medical Research Institute; University of Newcastle and Mothers and Babies Research Centre; Newcastle NSW Australia
| | - Kirsty G Pringle
- School of Biomedical Sciences and Pharmacy; Hunter Medical Research Institute; University of Newcastle and Mothers and Babies Research Centre; Newcastle NSW Australia
| | - Yu Wang
- School of Biomedical Sciences and Pharmacy; Hunter Medical Research Institute; University of Newcastle and Mothers and Babies Research Centre; Newcastle NSW Australia
| | - Karen J Gibson
- School of Medical Sciences; University of New South Wales; Sydney NSW Australia
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Ritz E, Pitt B. Mineralocorticoid receptor blockade-a novel approach to fight hyperkalaemia in chronic kidney disease. Clin Kidney J 2013; 6:464-8. [PMID: 26120440 PMCID: PMC4438399 DOI: 10.1093/ckj/sft084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 01/06/2023] Open
Abstract
Hyperkalaemia continues to be a major hazard of mineralocorticoid receptor blockade in an effort to retard the progression of chronic kidney disease (CKD). In cardiac patients on mineralocorticoid receptor blockade, RLY-5016 which captures K+ in the colon has been effective in reducing the risk of hyperkalaemia. This compound might be useful in CKD as well.
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Affiliation(s)
- E Ritz
- Nierenzentrum , University of Heidelberg , Heidelberg , Germany
| | - B Pitt
- Internal Medicine and Cardiovascular Disease , University of Michigan Medical School , Ann Arbor, MI , USA
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Aldosterone stimulates fibronectin synthesis in renal fibroblasts through mineralocorticoid receptor-dependent and independent mechanisms. Gene 2013; 531:23-30. [PMID: 23994292 DOI: 10.1016/j.gene.2013.08.047] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/13/2013] [Indexed: 11/22/2022]
Abstract
In addition to its role in regulation of salt transport in the kidney, the mineralocorticoid hormone aldosterone plays an independent role as a mediator of kidney injury and progression of chronic kidney disease. Studies in both animal models and patients have shown that aldosterone enhances the accumulation of extracellular matrix and progression of fibrosis in the kidney. However, the cellular mechanisms that lead to aldosterone-dependent fibrogenesis are poorly understood. In this study we find that aldosterone stimulates fibronectin synthesis through mineralocorticoid receptor (MCR) dependent activation of the c-Jun NH2-terminal protein kinase (JNK) and subsequent phosphorylation of the AP1 transcription factor c-jun, which forms a nuclear complex with the mineralocorticoid receptor in a kidney fibroblast cell line (NRK 49f). Furthermore, MCR-independent phosphorylation of Src family kinase induces IgF1 receptor phosphorylation, which leads to stimulation of the extracellular signal-regulated kinase (ERK1/2) to enhanced fibronectin synthesis. We further find that the IgF1-R-dependent signaling pathway activates fibronectin expression faster than the MCR-dependent pathway. We propose that the mechanisms described in this study are important to aldosterone-dependent progression of interstitial fibrosis in the kidney. Due to the duality of aldosterone-dependent activation of fibronectin synthesis in kidney fibroblasts, MCR-specific inhibitors may not entirely prevent the progression of fibrosis by aldosterone in the kidney.
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Salyer SA, Parks J, Barati MT, Lederer ED, Clark BJ, Klein JD, Khundmiri SJ. Aldosterone regulates Na(+), K(+) ATPase activity in human renal proximal tubule cells through mineralocorticoid receptor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2143-52. [PMID: 23684706 DOI: 10.1016/j.bbamcr.2013.05.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/15/2013] [Accepted: 05/08/2013] [Indexed: 12/21/2022]
Abstract
The mechanisms by which aldosterone increases Na(+), K(+) ATPase and sodium channel activity in cortical collecting duct and distal nephron have been extensively studied. Recent investigations demonstrate that aldosterone increases Na-H exchanger-3 (NHE-3) activity, bicarbonate transport, and H(+) ATPase in proximal tubules. However, the role of aldosterone in regulation of Na(+), K(+) ATPase in proximal tubules is unknown. We hypothesize that aldosterone increases Na(+), K(+) ATPase activity in proximal tubules through activation of the mineralocorticoid receptor (MR). Immunohistochemistry of kidney sections from human, rat, and mouse kidneys revealed that the MR is expressed in the cytosol of tubules staining positively for Lotus tetragonolobus agglutinin and type IIa sodium-phosphate cotransporter (NpT2a), confirming proximal tubule localization. Adrenalectomy in Sprague-Dawley rats decreased expression of MR, ENaC α, Na(+), K(+) ATPase α1, and NHE-1 in all tubules, while supplementation with aldosterone restored expression of above proteins. In human kidney proximal tubule (HKC11) cells, treatment with aldosterone resulted in translocation of MR to the nucleus and phosphorylation of SGK-1. Treatment with aldosterone also increased Na(+), K(+) ATPase-mediated (86)Rb uptake and expression of Na(+), K(+) ATPase α1 subunits in HKC11 cells. The effects of aldosterone on Na(+), K(+) ATPase-mediated (86)Rb uptake were prevented by spironolactone, a competitive inhibitor of aldosterone for the MR, and partially by Mifepristone, a glucocorticoid receptor (GR) inhibitor. These results suggest that aldosterone regulates Na(+), K(+) ATPase in renal proximal tubule cells through an MR-dependent mechanism.
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Affiliation(s)
- Sarah A Salyer
- Department of Medicine, Kidney Disease Program, University of Louisville, Louisville, KY, USA
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Dietary management of chronic kidney disease: protein restriction and beyond. Curr Opin Nephrol Hypertens 2013; 21:635-40. [PMID: 23079747 DOI: 10.1097/mnh.0b013e328357a69b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW More kidney protective strategies are needed to reduce the burden of complete kidney failure from chronic kidney disease (CKD). Clinicians sometimes use protein restriction as kidney protection despite its demonstrated lack of effectiveness in the only large-scale study. Small-scale studies support that dietary acid reduction is kidney-protective, including when done with base-inducing foods like fruits and vegetables. We review these studies in light of current kidney-protective recommendations. RECENT FINDINGS Animal models of CKD show that acid-inducing dietary protein exacerbates and base-inducing protein ameliorates nephropathy progression, and that increased intake of acid-inducing but not base-inducing dietary protein exacerbates progression. Clinical studies show that dietary acid reduction with Na-based alkali reduces kidney injury and slows nephropathy progression in patients with CKD and reduced glomerular filtration rate (GFR); base-inducing fruits and vegetables reduce kidney injury in patients with reduced GFR; and base-inducing fruits and vegetables improve metabolic acidosis in CKD. SUMMARY Protein type rather than amount might more importantly affect nephropathy progression. Base-inducing foods might be another way to reduce dietary acid, a strategy shown in small studies to slow nephropathy progression. Further studies will determine if CKD patients should be given base-inducing food as part of their management.
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Circulating aldosterone and mortality in female nursing home residents. Exp Gerontol 2013; 48:313-8. [DOI: 10.1016/j.exger.2013.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 12/11/2012] [Accepted: 01/07/2013] [Indexed: 11/19/2022]
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Arora MK, Singh UK. Molecular mechanisms in the pathogenesis of diabetic nephropathy: an update. Vascul Pharmacol 2013; 58:259-71. [PMID: 23313806 DOI: 10.1016/j.vph.2013.01.001] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 01/04/2013] [Accepted: 01/04/2013] [Indexed: 12/13/2022]
Abstract
Diabetes mellitus is known to trigger retinopathy, neuropathy and nephropathy. Diabetic nephropathy, a long-term major microvascular complication of uncontrolled hyperglycemia, affects a large population worldwide. Recent findings suggest that numerous pathways are activated during the course of diabetes mellitus and that these pathways individually or collectively play a role in the induction and progression of diabetic nephropathy. However, clinical strategies targeting these pathways to manage diabetic nephropathy remain unsatisfactory, as the number of diabetic patients with nephropathy is increasing yearly. To develop ground-breaking therapeutic options to prevent the development and progression of diabetic nephropathy, a comprehensive understanding of the molecular mechanisms involved in the pathogenesis of the disease is mandatory. Therefore, the purpose of this paper is to discuss the underlying mechanisms and downstream pathways involved in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Mandeep Kumar Arora
- Faculty of Pharmacy, Swami Vivekanand Subharti University, Meerut 250005, Uttar Pradesh, India.
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Green Tea Attenuates Oxidative Stress and Downregulates the Expression of Angiotensin II AT(1) Receptor in Renal and Hepatic Tissues of Streptozotocin-Induced Diabetic Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:409047. [PMID: 23243444 PMCID: PMC3518821 DOI: 10.1155/2012/409047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 10/13/2012] [Indexed: 02/06/2023]
Abstract
This study investigates the potential of green tea to modulate oxidative stress and angiotensin II AT1 receptor expression in renal and hepatic tissues of diabetic rats. Three groups of rats were studied after 8 weeks following diabetes induction: normal, streptozotocin-induced diabetic (diabetic control), and green-tea-treated diabetic rats. Total antioxidant, catalase, and malondialdehyde levels were assayed by standard procedures. Levels of AT1 receptor labeling, in renal and hepatic tissues of the three rat groups, were immunohistochemically investigated using an anti-AT1 receptor antibody. Levels of total antioxidant and catalase were significantly reduced, whereas malondialdehyde levels and AT1 receptor labeling were significantly increased in renal and hepatic tissues of diabetic control rats compared to normal rats. Compared to diabetic control rats, total antioxidant and catalase levels were significantly increased, whereas malondialdehyde levels and AT1 receptor labeling in the green-tea-treated diabetic group were significantly reduced throughout hepatic lobules and renal cortical and medullary vascular and tubular segments to levels comparable to those observed in normal rats. The capacity of green tea to modulate diabetes-induced oxidative stress and AT1 receptor upregulation may be beneficial in opposing the deleterious effects of excessive angiotensin II signaling, manifested by progressive renal and hepatic tissue damage.
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46
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Wesson DE, Jo CH, Simoni J. Angiotensin II receptors mediate increased distal nephron acidification caused by acid retention. Kidney Int 2012; 82:1184-94. [PMID: 22832514 DOI: 10.1038/ki.2012.267] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Patients with a moderately reduced glomerular filtration rate (GFR) typically have no metabolic acidosis and a urine net acid excretion comparable to those with normal GFR, supporting greater per nephron acidification with moderately reduced GFR. We modeled such patients using rats with a surgical reduction of 2/3 kidney mass, yielding animals with reduced GFR without metabolic acidosis. We then tested the hypothesis that reduction of nephron mass augments distal nephron acidification in remnant nephrons mediated by increased angiotensin II activity, and that the latter is induced by underlying acid retention. Nephron mass reduction yielded lower GFR than controls (sham operation), higher acid retention (measured by microdialysis of kidney cortex), higher distal nephron acidification, and higher plasma and kidney levels of angiotensin II, but plasma total CO(2) and urine net acid excretion were not different. Angiotensin II receptor antagonism reduced distal nephron acidification to levels similar to control. Dietary alkali that lowered acid retention to that of control also reduced plasma and kidney levels of angiotensin II and reduced distal nephron acidification to control. Angiotensin II receptor antagonism with dietary alkali had no significant added effect on distal nephron acidification. Thus, nephron reduction that moderately reduced GFR with no metabolic acidosis is characterized by increased angiotensin II activity. This mediates increased distal nephron acidification and is induced by acid retention.
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Affiliation(s)
- Donald E Wesson
- Texas A&M Health Sciences Center College of Medicine, Temple, Texas 76502, USA.
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Huang L, Nikolic-Paterson D, Ma F, Tesch G. Aldosterone Induces Kidney Fibroblast Proliferation via Activation of Growth Factor Receptors and PI3K/MAPK Signalling. ACTA ACUST UNITED AC 2012; 120:e115-22. [DOI: 10.1159/000339500] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 05/11/2012] [Indexed: 11/19/2022]
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Queisser N, Schupp N. Aldosterone, oxidative stress, and NF-κB activation in hypertension-related cardiovascular and renal diseases. Free Radic Biol Med 2012; 53:314-27. [PMID: 22609249 DOI: 10.1016/j.freeradbiomed.2012.05.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 05/07/2012] [Accepted: 05/07/2012] [Indexed: 02/07/2023]
Abstract
The mineralocorticoid aldosterone regulates electrolyte and fluid balance and is involved in blood pressure homoeostasis. Classically, it binds to its intracellular mineralocorticoid receptor to induce expression of proteins influencing the reabsorption of sodium and water in the distal nephron. Aldosterone gained special attention when large clinical studies showed that blocking its receptor in patients with cardiovascular diseases reduced their mortality. These patients present increased plasma aldosterone levels. The exact mechanisms of the potential toxic effects of aldosterone leading to cardiovascular damage are not known yet. The observation of reduced nitric oxide bioavailability in hyperaldosteronism implied the generation of oxidative stress by aldosterone. Subsequent studies confirmed the increase of oxidative stress markers in patients with chronic heart failure and in animal models of hyperaldosteronism. The effects of reactive oxygen species have been related to the activation of transcription factors, such as NF-κB. This review summarizes the present-day knowledge of aldosterone-induced oxidative stress and NF-κB activation in humans and different experimental models.
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Affiliation(s)
- Nina Queisser
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Str. 9, 97078 Würzburg, Germany
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Combined aliskiren and amlodipine reduce albuminuria via reduction in renal inflammation in diabetic rats. J Cardiovasc Pharmacol 2012; 59:281-7. [PMID: 22075749 DOI: 10.1097/fjc.0b013e31823fc3f5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We hypothesized that compared with hydrochlorothiazide (HCTZ), the renin inhibitor aliskiren (ALISK) or amlodipine (AMLO) and their combination reduce albuminuria via reduction in renal inflammation, independent of blood pressure (BP) changes. We studied normal and streptozotocin-induced diabetic (DM) Sprague-Dawley rats treated for 6 weeks with vehicle, ALISK, HCTZ, or AMLO individually and combined and evaluated the effects of treatments on BP, urine albumin to creatinine ratio, renal interstitial fluid levels of angiotensin II, tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6) and renal expression of TNF-α, IL-6, transforming growth factor beta 1, and nuclear factor kappa B. There were no differences in BP between treatments. Only ALISK and its combinations reduced renal interstitial fluid angiotensin II. Urine albumin to creatinine ratio increased in DM rats and decreased with ALISK alone or combined with HCTZ or AMLO. HCTZ or AMLO individually and combined did not influence urine albumin to creatinine ratio. Renal interstitial fluid TNF-α and IL-6, and the renal expression of TNF-α, IL-6, transforming growth factor beta 1, and nuclear factor kappa B were increased in DM rats. These renal inflammatory markers were reduced only with ALISK or AMLO individually or combined with other treatments. We conclude that ALISK alone and combined with HCTZ or AMLO reduced albuminuria in diabetes via reduction in renal inflammation, independent of BP changes.
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Garlic (Allium sativum) down-regulates the expression of angiotensin II AT1 receptor in adrenal and renal tissues of streptozotocin-induced diabetic rats. Inflammopharmacology 2012; 21:147-59. [DOI: 10.1007/s10787-012-0139-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 05/16/2012] [Indexed: 01/11/2023]
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