1
|
Lin C, Mazzuca MQ, Khalil RA. Increased uterine arterial tone, stiffness and remodeling with augmented matrix metalloproteinase-1 and -7 in uteroplacental ischemia-induced hypertensive pregnancy. Biochem Pharmacol 2024:116227. [PMID: 38643908 DOI: 10.1016/j.bcp.2024.116227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/29/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
Preeclampsia is a pregnancy-related disorder manifested as hypertensive pregnancy (HTN-Preg) and often fetal growth restriction (FGR), but the mechanisms involved are unclear. We have reported enhanced reactivity of systemic vessels in HTN-Preg rats, but the critical changes in the uterine circulation are less clear. We tested whether HTN-Preg involves localized aberrations in uterine arterial tone, stiffness and remodeling by matrix metalloproteinases (MMPs). Blood pressure (BP) and litter size were recorded in normal pregnant (Preg) rats and Preg rats with reduced uteroplacental perfusion pressure (RUPP). Isolated uterine arteries were placed in a pressure myograph for measuring intrinsic and extrinsic tone and arterial stiffness. Arteries were bathed in normal Krebs solution (2.5 mM Ca2+), Ca2+-free (2 mM EGTA) Krebs, treated with sodium nitroprusside (SNP), or endothelium denuded, then pressurized at 10 mmHg steps from 10 to 110 mmHg, and the % change in diameter was analyzed to measure total (active + passive), active Ca2+-dependent myogenic, passive, and endothelium-dependent tone, respectively. BP was higher and the litter size and pup weight were reduced in RUPP vs Preg rats. In normal Krebs, increasing intraluminal pressure caused smaller increments in diameter in arteries of RUPP vs Preg rats, suggesting greater total vascular tone. Arterial incubation in Ca2+-free Krebs, treatment with SNP or endothelium-removal abolished the differences in vascular tone, and subtraction of each of these components from total vascular tone revealed significant active Ca2+-dependent myogenic, passive, and endothelium-dependent tone, respectively, in RUPP vs Preg rats. The total and passive strain-stress curves were shifted leftward in arteries of RUPP vs Preg rats, indicating increased uterine arterial stiffness. Arterial sections showed decreased lumen/total and increased wall/total area, and immunohistochemistry revealed greater MMP-1 and MMP-7 staining particularly in the media, suggesting uterine arterial remodeling by MMPs in RUPP vs Preg rats. The increased uterine arterial active myogenic, passive, and endothelium-dependent tone, arterial stiffness and remodeling by MMPs would further reduce uterine blood flow and exacerbate uteroplacental ischemia, FGR and HTN-Preg.
Collapse
Affiliation(s)
- Chen Lin
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, United States
| | - Marc Q Mazzuca
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, United States
| | - Raouf A Khalil
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, United States.
| |
Collapse
|
2
|
Maeda T, Okawara M, Osakabe M, Yamaguchi H, Maeda T, Kurita H. Initial real-world experience of clazosentan for subarachnoid hemorrhage in Japan. World Neurosurg X 2024; 21:100253. [PMID: 38090191 PMCID: PMC10714223 DOI: 10.1016/j.wnsx.2023.100253] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 11/28/2023] [Indexed: 05/08/2024] Open
Abstract
BACKGROUND Cerebral vasospasm (CVS) is one of the most critical factors associated with clinical outcomes of patients with subarachnoid hemorrhage (SAH). Clazosentan has been investigated worldwide as a prophylactic agent to prevent CVS. We evaluated a new CVS management protocol which included clazosentan. METHODS Consecutive 138 patients with SAH, hospitalized in our institution between January 2017 and December 2022, were included in this study. Baseline characteristics, clinical findings, and operative records were analyzed retrospectively. From May 2022, 10 mg/h clazosentan was co-administered with fasudil to all patients according to the indication in the Japanese label. Patients admitted before this date received the conventional combined protocol using the fasudil hydrochloride, nicardipine, and ozagrel. RESULTS Eighteen (13.0%) patients received the new protocol during the CVS period (defined as day 1 up to day 14 after SAH onset). There were 54 (39.1%) elderly patients aged 75 years or older. Seventy-two (52.2%) patients underwent neurosurgical clipping, whereas 55 (39.9%) patients received endovascular coiling. Among the patients with new protocol, only one patient (5.6%) had symptomatic CVS, compared with 18 patients (15.0%) in those with conventional protocol. More patients who received the new protocol had fluid retention compared with control group (38.9% [7/18] vs. 8.3% [10/120]). Other results did not differ between the two groups. CONCLUSIONS Clinical outcomes of the new protocol were comparable to those of conventional protocol. Clazosentan may simplify anti-vasospasm treatment. Fluid retention was a specific side-effect of clazosentan, which requires attention especially in the first half of the CVS period.
Collapse
Affiliation(s)
- Takuma Maeda
- Department of Cerebrovascular Surgery, Saitama Medical University International Medical Center, Hidaka, Japan
- Department of Neurosurgery, Ohkawara Neurosurgical Hospital, Muroran, Japan
| | - Mai Okawara
- Department of Neurosurgery, Ohkawara Neurosurgical Hospital, Muroran, Japan
| | - Manabu Osakabe
- Department of Neurosurgery, Ohkawara Neurosurgical Hospital, Muroran, Japan
| | - Hiroyuki Yamaguchi
- Department of Neurosurgery, Ohkawara Neurosurgical Hospital, Muroran, Japan
| | - Takahiro Maeda
- Department of Neurosurgery, Ohkawara Neurosurgical Hospital, Muroran, Japan
| | - Hiroki Kurita
- Department of Cerebrovascular Surgery, Saitama Medical University International Medical Center, Hidaka, Japan
| |
Collapse
|
3
|
Li M, Armelloni S, Mattinzoli D, Ikehata M, Chatziantoniou C, Alfieri C, Molinari P, Chadjichristos CE, Malvica S, Castellano G. Crosstalk mechanisms between glomerular endothelial cells and podocytes in renal diseases and kidney transplantation. Kidney Res Clin Pract 2024; 43:47-62. [PMID: 38062623 PMCID: PMC10846991 DOI: 10.23876/j.krcp.23.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/20/2023] [Accepted: 08/10/2023] [Indexed: 02/06/2024] Open
Abstract
The glomerular filtration barrier (GFB), composed of endothelial cells, glomerular basement membrane, and podocytes, is a unique structure for filtering blood while detaining plasma proteins according to size and charge selectivity. Structurally, the fenestrated endothelial cells, which align the capillary loops, are in close proximity to mesangial cells. Podocytes are connected by specialized intercellular junctions known as slit diaphragms and are separated from the endothelial compartment by the glomerular basement membrane. Podocyte-endothelial cell communication or crosstalk is required for the development and maintenance of an efficient filtration process in physiological conditions. In pathological situations, communication also has an essential role in promoting or delaying disease progression. Podocytes and endothelial cells can secrete signaling molecules, which act as crosstalk effectors and, through binding to their target receptors, can trigger bidirectional paracrine or autocrine signal transduction. Moreover, the emerging evidence of extracellular vesicles derived from various cell types engaging in cell communication has also been reported. In this review, we summarize the principal pathways involved in the development and maintenance of the GFB and the progression of kidney disease, particularly in kidney transplantation.
Collapse
Affiliation(s)
- Min Li
- Renal Research Laboratory, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Silvia Armelloni
- Renal Research Laboratory, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Deborah Mattinzoli
- Renal Research Laboratory, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Masami Ikehata
- Renal Research Laboratory, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Christos Chatziantoniou
- Unité Mixte de Recherche Scientifique 1155, Institut National de la Santé et de la Recherche Médicale, Hôpital Tenon, Paris, France
- Faculty of Medicine, Sorbonne University, Paris, France
| | - Carlo Alfieri
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Paolo Molinari
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Christos E. Chadjichristos
- Unité Mixte de Recherche Scientifique 1155, Institut National de la Santé et de la Recherche Médicale, Hôpital Tenon, Paris, France
- Faculty of Medicine, Sorbonne University, Paris, France
| | - Silvia Malvica
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Castellano
- Department of Nephrology, Dialysis and Kidney Transplantation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| |
Collapse
|
4
|
Hakimi S, Dutta P, Layton AT. Coupling of renal sodium and calcium transport: a modeling analysis of transporter inhibition and sex differences. Am J Physiol Renal Physiol 2023; 325:F536-F551. [PMID: 37615047 DOI: 10.1152/ajprenal.00145.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/25/2023] Open
Abstract
Ca2+ transport along the nephron occurs via specific transcellular and paracellular pathways and is coupled to the transport of other electrolytes. Notably, Na+ transport establishes an electrochemical gradient to drive Ca2+ reabsorption. Hence, alterations in renal Na+ handling, under pathophysiological conditions or pharmacological manipulations, can have major effects on Ca2+ transport. An important class of pharmacological agent is diuretics, which are commonly prescribed for the management of blood pressure and fluid balance. The pharmacological targets of diuretics generally directly facilitate Na+ transport but also indirectly affect renal Ca2+ handling. To better understand the underlying mechanisms, we developed a computational model of electrolyte transport along the superficial nephron in the kidney of a male and female rat. Sex differences in renal Ca2+ handling are represented. Model simulations predicted in the female rat nephron lower Ca2+ reabsorption in the proximal tubule and thick ascending limb, but higher reabsorption in the late distal convoluted tubule and connecting tubule, compared with the male nephron. The male rat kidney model yielded a higher urinary Ca2+ excretion than the female model, consistent with animal experiments. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occurred in parallel, but those processes were dissociated in the distal convoluted tubule. Additionally, we conducted simulations of inhibition of channels and transporters that play a major role in Na+ and Ca2+ transport. Simulation results revealed alterations in transepithelial Ca2+ transport, with differential effects among nephron segments and between the sexes.NEW & NOTEWORTHY The kidney plays an important role in the maintenance of whole body Ca2+ balance by regulating Ca2+ reabsorption and excretion. This computational modeling study provides insights into how Ca2+ transport along the nephron is coupled to Na+. Model results indicated that along the proximal tubule and thick ascending limb, Ca2+ and Na+ transport occur in parallel, but those processes were dissociated in the distal convoluted tubule. Simulations also revealed sex-specific responses to different pharmacological manipulations.
Collapse
Affiliation(s)
- Shervin Hakimi
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Pritha Dutta
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
5
|
Becker BK, Grady CM, Markl AE, Torres Rodriguez AA, Pollock DM. Elevated renal afferent nerve activity in a rat model of endothelin B receptor deficiency. Am J Physiol Renal Physiol 2023; 325:F235-F247. [PMID: 37348026 PMCID: PMC10396274 DOI: 10.1152/ajprenal.00064.2023] [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: 03/21/2023] [Revised: 06/13/2023] [Accepted: 06/21/2023] [Indexed: 06/24/2023] Open
Abstract
Renal nerves have been an attractive target for interventions aimed at lowering blood pressure; however, the specific roles of renal afferent (sensory) versus efferent sympathetic nerves in mediating hypertension are poorly characterized. A number of studies have suggested that a sympathoexcitatory signal conveyed by renal afferents elicits increases in blood pressure, whereas other studies identified sympathoinhibitory afferent pathways. These sympathoinhibitory pathways have been identified as protective against salt-sensitive increases in blood pressure through endothelin B (ETB) receptor activation. We hypothesized that ETB-deficient (ETB-def) rats, which are devoid of functional ETB receptors except in adrenergic tissues, lack appropriate sympathoinhibition and have lower renal afferent nerve activity following a high-salt diet compared with transgenic controls. We found that isolated renal pelvises from high salt-fed ETB-def animals lack a response to a physiological stimulus, prostaglandin E2, compared with transgenic controls but respond equally to a noxious stimulus, capsaicin. Surprisingly, we observed elevated renal afferent nerve activity in intact ETB-def rats compared with transgenic controls under both normal- and high-salt diets. ETB-def rats have been previously shown to have heightened global sympathetic tone, and we also observed higher total renal sympathetic nerve activity in ETB-def rats compared with transgenic controls under both normal- and high-salt diets. These data indicate that ETB receptors are integral mediators of the sympathoinhibitory renal afferent reflex (renorenal reflex), and, in a genetic rat model of ETB deficiency, the preponderance of sympathoexcitatory renal afferent nerve activity prevails and may contribute to hypertension.NEW & NOTEWORTHY Here, we found that endothelin B receptors are an important contributor to renal afferent nerve responsiveness to a high-salt diet. Rats lacking endothelin B receptors have increased afferent nerve activity that is not responsive to a high-salt diet.
Collapse
Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Caroline M Grady
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alexa E Markl
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| |
Collapse
|
6
|
Oda Y, Nishi H, Nangaku M. Role of Inflammation in Progression of Chronic Kidney Disease in Type 2 Diabetes Mellitus: Clinical Implications. Semin Nephrol 2023; 43:151431. [PMID: 37865982 DOI: 10.1016/j.semnephrol.2023.151431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
Progression of chronic kidney disease in type 2 diabetes has been understood conventionally as a consequence of intraglomerular hemodynamic changes and aberrant metabolic pathways. However, an increasing body of experimental evidence has highlighted the role of inflammatory response in the progression of diabetic kidney disease. Macrophage polarization in response to specific microenvironmental stimuli affects the pathology of diabetic kidneys. The diabetic milieu also up-regulates inflammatory cytokines, chemokines, and adhesion molecules, and promotes inflammatory signal transduction pathways, including inflammasomes. Therefore, from a reverse translational perspective, modulation of the inflammatory response may be the driving force of the renoprotective effects of renin-angiotensin system inhibitors, sodium-glucose cotransporter-2 inhibitors, and mineralocorticoid receptor antagonists, all of which have been shown to slow disease progression. Currently, many agents that target the inflammation in the kidneys directly are evaluated in clinical trials. This article discusses recent clinical and experimental milestones in drug development for diabetic kidney disease with a perspective on inflammation in the kidneys. Such insights may enable a targeted approach to discovering novel drugs against chronic kidney disease in type 2 diabetes.
Collapse
Affiliation(s)
- Yasuhiro Oda
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Hiroshi Nishi
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| |
Collapse
|
7
|
Guthrie GL, Almutlaq RN, Sugahara S, Butt MK, Brooks CR, Pollock DM, Gohar EY. G protein-coupled estrogen receptor 1 regulates renal endothelin-1 signaling system in a sex-specific manner. Front Physiol 2023; 14:1086973. [PMID: 36733911 PMCID: PMC9887121 DOI: 10.3389/fphys.2023.1086973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023] Open
Abstract
Demographic studies reveal lower prevalence of hypertension among premenopausal females compared to age-matched males. The kidney plays a central role in the maintenance of sodium (Na+) homeostasis and consequently blood pressure. Renal endothelin-1 (ET-1) is a pro-natriuretic peptide that contributes to sex differences in blood pressure regulation and Na+ homeostasis. We recently showed that activation of renal medullary G protein-coupled estrogen receptor 1 (GPER1) promotes ET-1-dependent natriuresis in female, but not male, rats. We hypothesized that GPER1 upregulates the renal ET-1 signaling system in females, but not males. To test our hypothesis, we determined the effect of GPER1 deletion on ET-1 and its downstream effectors in the renal cortex, outer and inner medulla obtained from 12-16-week-old female and male mice. GPER1 knockout (KO) mice and wildtype (WT) littermates were implanted with telemetry transmitters for blood pressure assessment, and we used metabolic cages to determine urinary Na+ excretion. GPER1 deletion did not significantly affect 24-h mean arterial pressure (MAP) nor urinary Na+ excretion. However, GPER1 deletion decreased urinary ET-1 excretion in females but not males. Of note, female WT mice had greater urinary ET-1 excretion than male WT littermates, whereas no sex differences were observed in GPER1 KO mice. GPER1 deletion increased inner medullary ET-1 peptide content in both sexes but increased outer medullary ET-1 content in females only. Cortical ET-1 content increased in response to GPER1 deletion in both sexes. Furthermore, GPER1 deletion notably increased inner medullary ET receptor A (ETA) and decreased outer medullary ET receptor B (ETB) mRNA expression in male, but not female, mice. We conclude that GPER1 is required for greater ET-1 excretion in females. Our data suggest that GPER1 is an upstream regulator of renal medullary ET-1 production and ET receptor expression in a sex-specific manner. Overall, our study identifies the role of GPER1 as a sex-specific upstream regulator of the renal ET-1 system.
Collapse
Affiliation(s)
- Ginger L. Guthrie
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Rawan N. Almutlaq
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Sho Sugahara
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Maryam K. Butt
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Craig R. Brooks
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, United States
| | - David M. Pollock
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Eman Y. Gohar
- Division of Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, United States,*Correspondence: Eman Y. Gohar,
| |
Collapse
|
8
|
Soliman RH, Jin C, Taylor CM, Moura Coelho da Silva E, Pollock DM. Sex Differences in Diurnal Sodium Handling During Diet-Induced Obesity in Rats. Hypertension 2022; 79:1395-1408. [PMID: 35545941 PMCID: PMC9186154 DOI: 10.1161/hypertensionaha.121.18690] [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 Emerging evidence over the past several years suggests that diurnal control of sodium excretion is sex dependent and involves the renal endothelin system. Given recent awareness of disruptions of circadian function in obesity, we determined whether diet-induced obesity impairs renal handling of an acute salt load at different times of day and whether this varies by sex and is associated with renal endothelin dysfunction. METHODS Male and female Sprague-Dawley rats were placed on a high-fat diet for 8 weeks before assessing renal sodium handling and blood pressure. RESULTS Male, but not female, rats on high fat had a significantly reduced natriuretic response to acute NaCl injection at the beginning of their active period that was associated with lower endothelin 1 (ET-1) excretion, lower ET-1 mRNA expression in the cortex and outer medulla as well as lower ETB receptor expression in the outer medulla of the high-fat rats. Obese males also had significantly higher blood pressure (telemetry) that was exacerbated by adding high salt to the diet during the last 2 weeks. While female rats developed hypertension with a high-fat diet, they were not salt sensitive and ET-1 excretion was unchanged. CONCLUSIONS These data identify diet-induced obesity as a sex-specific disruptive factor for maintaining proper sodium handling. Although high-fat diets induce hypertension in both sexes, these data reveal that males are at greater risk of salt-dependent hypertension and further suggest that females have more redundant systems that can be productive against salt-sensitive hypertension in at least some circumstances.
Collapse
Affiliation(s)
- Reham H. Soliman
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham
| | - Chunhua Jin
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham
| | - Crystal M. Taylor
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham
| | - Emile Moura Coelho da Silva
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham
| | - David M. Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham
| |
Collapse
|
9
|
Tabeling C, González Calera CR, Lienau J, Höppner J, Tschernig T, Kershaw O, Gutbier B, Naujoks J, Herbert J, Opitz B, Gruber AD, Hocher B, Suttorp N, Heidecke H, Burmester GR, Riemekasten G, Siegert E, Kuebler WM, Witzenrath M. Endothelin B Receptor Immunodynamics in Pulmonary Arterial Hypertension. Front Immunol 2022; 13:895501. [PMID: 35757687 PMCID: PMC9221837 DOI: 10.3389/fimmu.2022.895501] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/09/2022] [Indexed: 01/08/2023] Open
Abstract
Introduction Inflammation is a major pathological feature of pulmonary arterial hypertension (PAH), particularly in the context of inflammatory conditions such as systemic sclerosis (SSc). The endothelin system and anti-endothelin A receptor (ETA) autoantibodies have been implicated in the pathogenesis of PAH, and endothelin receptor antagonists are routinely used treatments for PAH. However, immunological functions of the endothelin B receptor (ETB) remain obscure. Methods Serum levels of anti-ETB receptor autoantibodies were quantified in healthy donors and SSc patients with or without PAH. Age-dependent effects of overexpression of prepro-endothelin-1 or ETB deficiency on pulmonary inflammation and the cardiovascular system were studied in mice. Rescued ETB-deficient mice (ETB-/-) were used to prevent congenital Hirschsprung disease. The effects of pulmonary T-helper type 2 (Th2) inflammation on PAH-associated pathologies were analyzed in ETB-/- mice. Pulmonary vascular hemodynamics were investigated in isolated perfused mouse lungs. Hearts were assessed for right ventricular hypertrophy. Pulmonary inflammation and collagen deposition were assessed via lung microscopy and bronchoalveolar lavage fluid analyses. Results Anti-ETB autoantibody levels were elevated in patients with PAH secondary to SSc. Both overexpression of prepro-endothelin-1 and rescued ETB deficiency led to pulmonary hypertension, pulmonary vascular hyperresponsiveness, and right ventricular hypertrophy with accompanying lymphocytic alveolitis. Marked perivascular lymphocytic infiltrates were exclusively found in ETB-/- mice. Following induction of pulmonary Th2 inflammation, PAH-associated pathologies and perivascular collagen deposition were aggravated in ETB-/- mice. Conclusion This study provides evidence for an anti-inflammatory role of ETB. ETB seems to have protective effects on Th2-evoked pathologies of the cardiovascular system. Anti-ETB autoantibodies may modulate ETB-mediated immune homeostasis.
Collapse
Affiliation(s)
- Christoph Tabeling
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Carla R González Calera
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jasmin Lienau
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jakob Höppner
- Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thomas Tschernig
- Institute of Anatomy and Cell Biology, University of Saarland, Homburg, Germany
| | - Olivia Kershaw
- Department of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - Birgitt Gutbier
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jan Naujoks
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Julia Herbert
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Bastian Opitz
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Achim D Gruber
- Department of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University of Heidelberg, University Medical Centre Mannheim, Heidelberg, Germany.,Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, School of Medicine, Hunan Normal University, Changsha, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China
| | - Norbert Suttorp
- Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,German Center for Lung Research (DZL), Partner Site Charité, Berlin, Germany
| | | | - Gerd-R Burmester
- Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Elise Siegert
- Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.,Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Wolfgang M Kuebler
- German Center for Lung Research (DZL), Partner Site Charité, Berlin, Germany.,Institute of Physiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site, Berlin, Germany.,St. Michael's Hospital, Keenan Research Centre for Biomedical Science, Toronto, ON, Canada.,Departments of Physiology and Surgery, University of Toronto, Toronto, ON, Canada
| | - Martin Witzenrath
- Division of Pulmonary Inflammation, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Infectious Diseases and Respiratory Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.,German Center for Lung Research (DZL), Partner Site Charité, Berlin, Germany
| |
Collapse
|
10
|
Mutations in rhodopsin, endothelin B receptor, and CC chemokine receptor 5 in large animals: Modeling human diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:155-178. [PMID: 35595348 DOI: 10.1016/bs.pmbts.2022.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of cell membrane receptors involved in modulating almost all physiological processes by transducing extracellular signals into the cytoplasm. Dysfunctions of GPCR-regulated signaling result in diverse human diseases, making GPCRs the most popular drug targets for human medicine. Large animals share higher similarities (in physiology and metabolism) with humans than rodents. Similar to findings in human genetics, diverse diseases caused by mutations in GPCR genes have also been discovered in large animals. Rhodopsin, endothelin B receptor, and CC chemokine receptor type 5 have been shown to be involved in human retinitis pigmentosa, Hirschsprung disease, and HIV infection/AIDS, respectively, and several mutations of these GPCRs have also been identified from large animals. The large animals with naturally occurring mutations of these GPCRs provide an opportunity to gain a better understanding of the pathogenesis of human diseases, and can be used for preclinical trials of therapies for human diseases. In this review, we aim to summarize the naturally occurring mutations of these three GPCRs in large animals and humans.
Collapse
|
11
|
Soliman RH, Pollock DM. Circadian Control of Sodium and Blood Pressure Regulation. Am J Hypertens 2021; 34:1130-1142. [PMID: 34166494 PMCID: PMC9526808 DOI: 10.1093/ajh/hpab100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/12/2021] [Accepted: 06/23/2021] [Indexed: 01/26/2023] Open
Abstract
The attention for the control of dietary risk factors involved in the development of hypertension, includes a large effort on dietary salt restrictions. Ample studies show the beneficial role of limiting dietary sodium as a lifestyle modification in the prevention and management of essential hypertension. Not until the past decade or so have studies more specifically investigated diurnal variations in renal electrolyte excretion, which led us to the hypothesis that timing of salt intake may impact cardiovascular health and blood pressure regulation. Cell autonomous molecular clocks as the name implies, function independently to maintain optimum functional rhythmicity in the face of environmental stressors such that cellular homeostasis is maintained at all times. Our understanding of mechanisms influencing diurnal patterns of sodium excretion and blood pressure has expanded with the discovery of the circadian clock genes. In this review, we discuss what is known about circadian regulation of renal sodium handling machinery and its influence on blood pressure regulation, with timing of sodium intake as a potential modulator of the kidney clock.
Collapse
Affiliation(s)
- Reham H Soliman
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David M Pollock
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| |
Collapse
|
12
|
Chen KC, Chen KC, Song ZM, Croaker GD. Structural heart defects associated with ET B mutation, a cause of Hirschsprung disease. BMC Cardiovasc Disord 2021; 21:475. [PMID: 34600481 PMCID: PMC8487587 DOI: 10.1186/s12872-021-02281-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HSCR, a colonic neurocristopathy affecting 1/5000 births, is suggested to associate with cardiac septal defects and conotruncal malformations. However, we question subtle cardiac changes maybe more commonly present due to multi-regulations by HSCR candidate genes, in this instance, ETB. To investigate, we compared the cardiac morphology and quantitative measurements of sl/sl rat to those of the control group. METHODS Eleven neonatal rats were generated from heterozygote (ETB+/-) crossbreeding. Age and bodyweight were recorded at time of sacrifice. Diffusion-staining protocols with 1.5% iodine solution was completed prior to micro-CT scanning. All rats were scanned using an in vivo micro-CT scanner, Caliper Quantum FX, followed by two quality-control scans using a custom-built ex vivo micro-CT system. All scans were reviewed for gross cardiac dysmorphology. Micro-CT data were segmented semi-automatically post-NLM filtering for: whole-heart, LV, RV, LA, RA, and aortic arch. Measurements were taken with Drishti. Following image analysis, PCR genotyping of rats was performed: five sl/sl rats, three wildtype, and three heterozygotes. Statistical comparisons on organ volume, growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control group. RESULTS Cardiac morphology and constituents were preserved. However, significant volumetric reductions were recorded in sl/sl rats with respect to the control: whole heart (38.70%, p value = 0.02); LV (41.22%, p value = 0.01), RV (46.15%, p value = 0.02), LA (44.93%, p value = 0.06), and RA (39.49%, p value = 0.02). Consistent trend was observed in growth rate (~ 20%) and organ-volume/bodyweight ratios (~ 25%). On the contrary, measurements on aortic arch demonstrated no significant difference among the two groups. CONCLUSION Despite the presence of normal morphology, significant cardiac growth retardation was detected in sl/sl rat, supporting the likely association of cardiac anomalies with HSCR, at least in ETB-/- subtype. Structural reduction was likely due to a combination of failure to thrive from enteric dysfunction, alterations to CaNCC colonization, and importantly coronary hypoperfusion from elevated ET-1/ETA-mediated hypervasoconstriction. Little correlation was detected between aortic arch development and sl/sl rat, supporting minor ETB role in large vessels. Although further clinical study is warranted, HSCR patients may likely require cardiac assessment in view of potential congenital cardiac defects.
Collapse
Affiliation(s)
- Ko-Chin Chen
- Australian National University Medical School, Florey Building 54 Mills Road, Acton, ACT 2601 Australia
| | - Ko-Chien Chen
- MD Anderson Cancer Centre, University of Texas, Houston, TX 77030 USA
| | - Zan-Min Song
- The John Curtin School of Medical Research, Australian National University Medical School, Acton, ACT 2601 Australia
| | - Geoffrey D. Croaker
- Australian National University Medical School, Florey Building 54 Mills Road, Acton, ACT 2601 Australia
- Paediatric Surgery, The Canberra Hospital, Garran, ACT Australia
| |
Collapse
|
13
|
Chen KC, Song ZM, Croaker GD. Brain size reductions associated with endothelin B receptor mutation, a cause of Hirschsprung's disease. BMC Neurosci 2021; 22:42. [PMID: 34147087 PMCID: PMC8214790 DOI: 10.1186/s12868-021-00646-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 06/08/2021] [Indexed: 01/03/2023] Open
Abstract
Background ETB has been reported to regulate neurogenesis and vasoregulation in foetal development. Its dysfunction was known to cause HSCR, an aganglionic colonic disorder with syndromic forms reported to associate with both small heads and developmental delay. We therefore asked, "is CNS maldevelopment a more general feature of ETB mutation?" To investigate, we reviewed the micro-CT scans of an ETB−/− model animal, sl/sl rat, and quantitatively evaluated the structural changes of its brain constituents. Methods Eleven neonatal rats generated from ETB+/− cross breeding were sacrificed. Micro-CT scans were completed following 1.5% iodine-staining protocols. All scans were reviewed for morphological changes. Selected organs were segmented semi-automatically post-NLM filtering: TBr, T-CC, T-CP, OB, Med, Cer, Pit, and S&I Col. Volumetric measurements were made using Drishti rendering software. Rat genotyping was completed following analysis. Statistical comparisons on organ volume, organ growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control groups based on autosomal recessive inheritance. One-way ANOVA was also performed to evaluate potential dose-dependent effect. Results sl/sl rat has 16.32% lower body weight with 3.53% lower growth rate than the control group. Gross intracranial morphology was preserved in sl/sl rats. However, significant volumetric reduction of 20.33% was detected in TBr; similar reductions were extended to the measurements of T-CC, T-CP, OB, Med, and Pit. Consistently, lower brain and selected constituent growth rates were detected in sl/sl rat, ranging from 6.21% to 11.51% reduction. Lower organ volume/bodyweight ratio was detected in sl/sl rats, reflecting disproportional neural changes with respect to body size. No consistent linear relationships exist between ETB copies and intracranial organ size or growth rates. Conclusion Although ETB−/− mutant has a normal CNS morphology, significant size reductions in brain and constituents were detected. These structural changes likely arise from a combination of factors secondary to dysfunctional ET-1/ET-3/ETB signalling, including global growth impairment from HSCR-induced malnutrition and dysregulations in the neurogenesis, angiogenesis, and cerebral vascular control. These changes have important clinical implications, such as autonomic dysfunction or intellectual delay. Although further human study is warranted, our study suggested comprehensive managements are required for HSCR patients, at least in ETB−/− subtype. Supplementary Information The online version contains supplementary material available at 10.1186/s12868-021-00646-z.
Collapse
Affiliation(s)
- Ko-Chin Chen
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.
| | - Zan-Min Song
- Medical School, Australian National University, Canberra, ACT, 2601, Australia
| | - Geoffrey D Croaker
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.,The Canberra Hospital, Yamba Drive, Garran, ACT, 2605, Australia
| |
Collapse
|
14
|
Becker BK, Johnston JG, Young CM, Torres Rodriguez AA, Jin C, Pollock DM. Endothelin B receptors impair baroreflex function and increase blood pressure variability during high salt diet. Auton Neurosci 2021; 232:102796. [PMID: 33798837 PMCID: PMC8040376 DOI: 10.1016/j.autneu.2021.102796] [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: 07/16/2020] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 10/21/2022]
Abstract
Baroreflex function is an integral component maintaining consistent blood pressure. Hypertension is often associated with baroreflex dysfunction, and environmental risk factors such as high salt diet exacerbate hypertension in subjects with baroreflex dysfunction. However, the interactions between high salt diet, baroreflex dysfunction, and hypertension are incompletely understood. The endothelin system is another potent mediator of blood pressure control especially in response to a high salt diet. We hypothesized that the endothelin B (ETB) receptor activation on adrenergic nerves decreases baroreflex sensitivity. We utilized male ETB receptor deficient (ETB-def) rats that express functional ETB receptors only on adrenergic nerves and transgenic (TG) controls to evaluate baroreflex function during normal (0.49% NaCl) and high (4.0% NaCl) salt diets. In conscious rats equipped with telemetry, ETB-def rats had an increased lability of systolic blood pressure (SBP) compared to TG controls as indicated by higher standard deviation (SD) of SBP under both normal (10.2 ± 0.6 vs. 12.4 ± 0.9 mmHg, respectively, p = 0.0001) and high (11.7 ± 0.6 vs. 16.1 ± 1.0 mmHg, p = 0.0001) salt diets. In anesthetized preparations, ETB-def rats displayed reduced heart rate (p genotype = 0.0167) and renal sympathetic nerve (p genotype = 0.0022) baroreflex sensitivity. We then gave male Sprague-Dawley rats the selective ETB receptor antagonist, A-192621 (10 mg/kg/day), to block ETB receptors. Following ETB receptor antagonism, even though SBP increased (131 ± 7 before vs. 152 ± 8 mmHg after, p < 0.0001), the lability (standard deviation) of SBP decreased (9.3 ± 2.0 vs. 7.1 ± 1.1 mmHg, p = 0.0155). These data support our hypothesis that ETB receptors on adrenergic nerves contribute to baroreflex dysfunction.
Collapse
Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Carolyn M Young
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| |
Collapse
|
15
|
Endothelin-targeted new treatments for proteinuric and inflammatory glomerular diseases: focus on the added value to anti-renin-angiotensin system inhibition. Pediatr Nephrol 2021; 36:763-775. [PMID: 32185491 DOI: 10.1007/s00467-020-04518-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/06/2020] [Accepted: 02/21/2020] [Indexed: 12/11/2022]
Abstract
Chronic kidney disease (CKD) is the main cause of end-stage renal disease worldwide arising as a frequent complication of diabetes, obesity, and hypertension. Current therapeutic options, mainly based of inhibition of the renin-angiotensin system (RAS), provide imperfect renoprotection if started at an advanced phase of the disease, and treatments that show or even reverse the progression of CKD are needed. The endothelin (ET) system contributes to the normal renal physiology; however, robust evidence suggests a key role of ET-1 and its cognate receptors, in the progression of CKD. The effectiveness of ET receptor antagonists in ameliorating renal hemodynamics and fibrosis has been largely demonstrated in different experimental models. A significant antiproteinuric effect of ET receptor antagonists has been found in diabetic and non-diabetic CKD patients even on top of RAS blockade, and emerging evidence from ongoing clinical trials highlights their beneficial effects on a wide range of kidney disorders.
Collapse
|
16
|
Gohar EY, Pollock DM. Functional Interaction of Endothelin Receptors in Mediating Natriuresis Evoked by G Protein-Coupled Estrogen Receptor 1. J Pharmacol Exp Ther 2020; 376:98-105. [PMID: 33127751 PMCID: PMC7788354 DOI: 10.1124/jpet.120.000322] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 10/26/2020] [Indexed: 01/14/2023] Open
Abstract
The G protein–coupled estrogen receptor 1 (GPER1) mediates rapid estrogenic signaling. We recently reported that activation of GPER1 in the renal medulla evokes endothelin-1–dependent natriuresis in female, but not male, rats. However, the involvement of the ET receptors, ETA and ETB, underlying GPER1 natriuretic action remain unclear. In this study, we used genetic and pharmacologic methods to identify the contributions of ETA and ETB in mediating this female-specific natriuretic effect of renal medullary GPER1. Infusion of the GPER1-selective agonist G1 (5 pmol/kg per minute) into the renal medulla for 40 minutes increased Na+ excretion and urine flow in anesthetized female ETB-deficient (ETB def) rats and littermate controls but did not affect blood pressure or urinary K+ excretion in either group. Pretreatment with the selective ETA inhibitor ABT-627 (5 mg/kg, intravenous) abolished G1-induced natriuresis in ETB def rats. To further isolate the effects of inhibiting either receptor alone, we conducted the same experiments in anesthetized female Sprague-Dawley (SD) rats pretreated or not with ABT-627 and/or the selective ETB inhibitor A-192621 (10 mg/kg, intravenous). Neither antagonism of ETA nor antagonism of ETB receptor alone affected the G1-induced increase in Na+ excretion and urine flow in SD rats. However, simultaneous antagonism of both receptors completely abolished these effects. These data suggest that ETA and ETB receptors can mediate the natriuretic and diuretic response to renal medullary GPER1 activation in female rats.
Collapse
Affiliation(s)
- Eman Y Gohar
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Alabama (E.Y.G, D.M.P); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt (E.Y.G)
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Alabama (E.Y.G, D.M.P); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt (E.Y.G)
| |
Collapse
|
17
|
Hu R, McDonough AA, Layton AT. Sex differences in solute transport along the nephrons: effects of Na + transport inhibition. Am J Physiol Renal Physiol 2020; 319:F487-F505. [PMID: 32744084 DOI: 10.1152/ajprenal.00240.2020] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Each day, ~1.7 kg of NaCl and 180 liters of water are reabsorbed by nephron segments in humans, with urinary excretion fine tuned to meet homeostatic requirements. These tasks are coordinated by a spectrum of renal Na+ transporters and channels. The goal of the present study was to investigate the extent to which inhibitors of transepithelial Na+ transport (TNa) along the nephron alter urinary solute excretion and how those effects may vary between male and female subjects. To accomplish that goal, we developed sex-specific multinephron models that represent detailed transcellular and paracellular transport processes along the nephrons of male and female rat kidneys. We simulated inhibition of Na+/H+ exchanger 3 (NHE3), bumetanide-sensitive Na+-K+-2Cl- cotransporter (NKCC2), Na+-Cl- cotransporter (NCC), and amiloride-sensitive epithelial Na+ channel (ENaC). NHE3 inhibition simulations predicted a substantially reduced proximal tubule TNa, and NKCC2 inhibition substantially reduced thick ascending limb TNa. Both gave rise to diuresis, natriuresis, and kaliuresis, with those effects stronger in female rats. While NCC inhibition was predicted to have only minor impact on renal TNa, it nonetheless had a notable effect of enhancing excretion of Na+, K+, and Cl-, particularly in female rats. Inhibition of ENaC was predicted to have opposite effects on the excretion of Na+ (increased) and K+ (decreased) and to have only a minor impact on whole kidney TNa. Unlike inhibition of other transporters, ENaC inhibition induced stronger natriuresis and diuresis in male rats than female rats. Overall, model predictions agreed well with measured changes in Na+ and K+ excretion in response to diuretics and Na+ transporter mutations.
Collapse
Affiliation(s)
- Rui Hu
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Alicia A McDonough
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada.,Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
18
|
Yang Y, Li M, Zou X, Chen C, Zheng S, Fu C, Chen K, Jose PA, Lan C, Liu Y. Role of GRK4 in the regulation of the renal ETB receptor in hypertension. FASEB J 2020; 34:11594-11604. [PMID: 32687659 DOI: 10.1096/fj.201902552r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 06/07/2020] [Accepted: 06/15/2020] [Indexed: 01/11/2023]
Abstract
The endothelin receptor type B (ETBR) regulates water and electrolyte balance and blood pressure, in part, by inhibiting renal sodium transport. Our preliminary study found that the ETBR-mediated diuresis and natriuresis are impaired in hypertension with unknown mechanism. Persistently increased activity of G protein-coupled receptor kinase 4 (GRK4), caused by increased expression or genetic variants (eg, GRKγ142V), impairs the ability of the kidney to excrete a sodium load, in part, by impairing renal dopamine D1 receptor function through persistent phosphorylation. Our present study found that although renal ETBR expression was not different between Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHRs), renal ETBR phosphorylation was higher in SHRs. The role of hyper-phosphorylation in impaired ETBR-function was supported by results in human (h) GRK4γ transgenic mice. Stimulation of ETBR by BQ3020-induced natriuresis in human (h) GRK4γ wild-type (WT) mice. However, in hGRK4γ 142V transgenic mice, the renal ETBR was hyperphosphorylated and ETBR-mediated natriuresis and diuresis were not evident. There were co-localization and co-immunoprecipitation of ETBR and GRK4 in renal proximal tubule (RPT) cells from both WKY and SHRs but was greater in the latter than the former group. SiRNA-mediated downregulation of GRK4 expression, recovered the impaired inhibitory effect of ETBR on Na+ -K+ -ATPase activity in RPT cells from SHR. In vivo downregulation of renal GRK4 expression, via ultrasound-targeted microbubble destruction, decreased ETBR phosphorylation and restored ETBR-mediated natriuresis and diuresis in SHRs. This study provides a mechanism by which GRK4, via regulation of renal ETBR function, participates in the pathogenesis of hypertension.
Collapse
Affiliation(s)
- Yang Yang
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Meixiang Li
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China.,The First People's Hospital of Liangjiang New District, Chongqing, P.R. China
| | - Xue Zou
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Caiyu Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Shuo Zheng
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Chunjiang Fu
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Ken Chen
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Pedro A Jose
- Division of Renal Diseases & Hypertension, Department of Medicine and Pharmacology/Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Cong Lan
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China
| | - Yukai Liu
- Department of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, P.R. China.,Chongqing Institute of Cardiology, Chongqing, P.R. China.,Chongqing Cardiovascular Clinical Research Center, Chongqing, P.R. China.,The First People's Hospital of Liangjiang New District, Chongqing, P.R. China
| |
Collapse
|
19
|
Kuczmarski AV, Shoemaker LN, Hobson JC, Edwards DG, Wenner MM. Altered endothelial ET B receptor expression in postmenopausal women. Am J Physiol Heart Circ Physiol 2020; 319:H242-H247. [PMID: 32559137 DOI: 10.1152/ajpheart.00342.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The endothelin system plays an important role in mediating vascular function. The endothelin-B receptor (ETBR) on endothelial cells mediates vasodilation via nitric oxide production. The vasodilatory effect of the ETBR is lost following menopause and may contribute to impaired vascular endothelial function in postmenopausal women (PMW). However, it is unclear if these functional changes are due to changes in ETBR expression on the endothelium. Therefore, the purpose of this study was to test the hypothesis that endothelial cell ETBR expression is lower in PMW compared with young women (YW). Primary endothelial cells were harvested from the antecubital vein of healthy PMW (n = 15, 60 ± 6 yr) and YW (n = 15, 22 ± 2 yr). Cells were identified as endothelial cells by staining for vascular endothelial cadherin, and nuclear integrity was assessed using 4',6-diamidino-2-phenylindole (DAPI). Within those cells, ETBR was quantified using immunocytochemistry; fluorescence intensity was measured in 30 cells and averaged for each participant. Endothelial function was assessed using brachial artery flow-mediated dilation (FMD). Endothelial cell ETBR expression was lower in PMW [0.46 ± 0.11 arbitrary units (AU)] compared with YW (0.58 ± 0.14 AU; P = 0.02). Furthermore, significant correlations between ETBR expression and FMD (r = 0.47, P < 0.01), total cholesterol (r = -0.38, P = 0.04), and LDL cholesterol (r = -0.39, P = 0.03) were observed. These data demonstrate that endothelial cell ETBR expression is attenuated in PMW. These novel findings provide additional insight into the mechanisms underlying vascular endothelial dysfunction in PMW.NEW & NOTEWORTHY Our study provides novel data demonstrating attenuated endothelial ETBR expression in postmenopausal women. Furthermore, our data extend current knowledge by demonstrating a positive relation between ETBR expression and brachial artery flow-mediated dilation. These findings provide additional mechanistic insight into vascular endothelial dysfunction in postmenopausal women.
Collapse
Affiliation(s)
- Andrew V Kuczmarski
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Leena N Shoemaker
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Joshua C Hobson
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| |
Collapse
|
20
|
Rivera-Gonzalez OJ, Kasztan M, Johnston JG, Hyndman KA, Speed JS. Loss of endothelin type B receptor function improves insulin sensitivity in rats. Can J Physiol Pharmacol 2020; 98:604-610. [PMID: 32083942 PMCID: PMC7442597 DOI: 10.1139/cjpp-2019-0666] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
High salt intake (HS) is associated with obesity and insulin resistance. ET-1, a peptide released in response to HS, inhibits the actions of insulin on cultured adipocytes through ET-1 type B (ETB) receptors; however, the in vivo implications of ETB receptor activation on lipid metabolism and insulin resistance is unknown. We hypothesized that activation of ETB receptors in response to HS intake promotes dyslipidemia and insulin resistance. In normal salt (NS) fed rats, no significant difference in body mass or epididymal fat mass was observed between control and ETB deficient rats. After 2 weeks of HS, ETB-deficient rats had significantly lower body mass and epididymal fat mass compared to controls. Nonfasting plasma glucose was not different between genotypes; however, plasma insulin concentration was significantly lower in ETB-deficient rats compared to controls, suggesting improved insulin sensitivity. In addition, ETB-deficient rats had higher circulating free fatty acids in both NS and HS groups, with no difference in plasma triglycerides between genotypes. In a separate experiment, ETB-deficient rats had significantly lower fasting blood glucose and improved glucose and insulin tolerance compared to controls. These data suggest that ET-1 promotes adipose deposition and insulin resistance via the ETB receptor.
Collapse
Affiliation(s)
- Osvaldo J Rivera-Gonzalez
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Kelly A Hyndman
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Joshua S Speed
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| |
Collapse
|
21
|
Tutunea-Fatan E, Lee JC, Denker BM, Gunaratnam L. Heterotrimeric Gα 12/13 proteins in kidney injury and disease. Am J Physiol Renal Physiol 2020; 318:F660-F672. [PMID: 31984793 DOI: 10.1152/ajprenal.00453.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Gα12 and Gα13 are ubiquitous members of the heterotrimeric guanine nucleotide-binding protein (G protein) family that play central and integrative roles in the regulation of signal transduction cascades within various cell types in the kidney. Gα12/Gα13 proteins enable the kidney to adapt to an ever-changing environment by transducing stimuli from cell surface receptors and accessory proteins to effector systems. Therefore, perturbations in Gα12/Gα13 levels or their activity can contribute to the pathogenesis of various renal diseases, including renal cancer. This review will highlight and discuss the complex and expanding roles of Gα12/Gα13 proteins on distinct renal pathologies, with emphasis on more recently reported findings. Deciphering how the different Gα12/Gα13 interaction networks participate in the onset and development of renal diseases may lead to the discovery of new therapeutic strategies.
Collapse
Affiliation(s)
- Elena Tutunea-Fatan
- Matthew Mailing Centre for Translational Transplant Studies, Lawson Health Research Institute, London, Ontario, Canada
| | - Jasper C Lee
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Bradley M Denker
- Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Lakshman Gunaratnam
- Matthew Mailing Centre for Translational Transplant Studies, Lawson Health Research Institute, London, Ontario, Canada.,Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada.,Division of Nephrology, Department of Medicine, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
22
|
Soliman RH, Johnston JG, Gohar EY, Taylor CM, Pollock DM. Greater natriuretic response to ENaC inhibition in male versus female Sprague-Dawley rats. Am J Physiol Regul Integr Comp Physiol 2020; 318:R418-R427. [PMID: 31913682 DOI: 10.1152/ajpregu.00060.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Genes for the epithelial sodium channel (ENaC) subunits are expressed in a circadian manner, but whether this results in time-of-day differences in activity is not known. Recent data show that protein expression of ENaC subunits is higher in kidneys from female rats, yet females are more efficient in excreting an acute salt load. Thus, our in vivo study determined whether there is a time-of-day difference as well as a sex difference in the response to ENaC inhibition by benzamil. Our results showed that the natriuretic and diuretic responses to a single dose of benzamil were significantly greater in male compared with female rats whether given at the beginning of the inactive period [Zeitgeber time 0 (ZT0), 7 AM] or active period (ZT12, 7 PM). However, the response to benzamil was not significantly different between ZT0 and ZT12 dosing in either male or female rats. There was no difference in renal cortical α-ENaC protein abundance between ZT0 and ZT12 or males and females. Given previous reports of flow-induced stimulation of endothelin-1 (ET-1) production and sex differences in the renal endothelin system, we measured urinary ET-1 excretion to assess the effects of increased urine flow on intrarenal ET-1. ET-1 excretion was significantly increased following benzamil administration in both sexes, but this increase was significantly greater in females. These results support the hypothesis that ENaC activity is less prominent in maintaining Na+ balance in females independent of renal ET-1. Because ENaC subunit genes and protein expression vary by time of day and are greater in female rat kidneys, this suggests a clear disconnect between ENaC expression and channel activity.
Collapse
Affiliation(s)
- Reham H Soliman
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jermaine G Johnston
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Eman Y Gohar
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Crystal M Taylor
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Section of Cardio-renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
23
|
De Miguel C, Sedaka R, Kasztan M, Lever JM, Sonnenberger M, Abad A, Jin C, Carmines PK, Pollock DM, Pollock JS. Tauroursodeoxycholic acid (TUDCA) abolishes chronic high salt-induced renal injury and inflammation. Acta Physiol (Oxf) 2019; 226:e13227. [PMID: 30501003 DOI: 10.1111/apha.13227] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 10/23/2018] [Accepted: 11/22/2018] [Indexed: 12/23/2022]
Abstract
AIM Chronic high salt intake exaggerates renal injury and inflammation, especially with the loss of functional ETB receptors. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone and bile salt that is approved for the treatment of hepatic diseases. Our aim was to determine whether TUDCA is reno-protective in a model of ETB receptor deficiency with chronic high salt-induced renal injury and inflammation. METHODS ETB -deficient and transgenic control rats were placed on normal (0.8% NaCl) or high salt (8% NaCl) diet for 3 weeks, receiving TUDCA (400 mg/kg/d; ip) or vehicle. Histological and biochemical markers of kidney injury, renal cell death and renal inflammation were assessed. RESULTS In ETB -deficient rats, high salt diet significantly increased glomerular and proximal tubular histological injury, proteinuria, albuminuria, excretion of tubular injury markers KIM-1 and NGAL, renal cortical cell death and renal CD4+ T cell numbers. TUDCA treatment increased proximal tubule megalin expression as well as prevented high salt diet-induced glomerular and tubular damage in ETB -deficient rats, as indicated by reduced kidney injury markers, decreased glomerular permeability and proximal tubule brush border restoration, as well as reduced renal inflammation. However, TUDCA had no significant effect on blood pressure. CONCLUSIONS TUDCA protects against the development of glomerular and proximal tubular damage, decreases renal cell death and inflammation in the renal cortex in rats with ETB receptor dysfunction on a chronic high salt diet. These results highlight the potential use of TUDCA as a preventive tool against chronic high salt induced renal damage.
Collapse
Affiliation(s)
- Carmen De Miguel
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Randee Sedaka
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Malgorzata Kasztan
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Jeremie M. Lever
- Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Michelle Sonnenberger
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Andrew Abad
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Chunhua Jin
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Pamela K. Carmines
- Department of Cellular and Integrative Physiology University of Nebraska Medical Center Omaha Nebraska
| | - David M. Pollock
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| | - Jennifer S. Pollock
- Section of Cardio‐Renal Physiology and Medicine, Division of Nephrology, Department of Medicine University of Alabama at Birmingham Birmingham Alabama
| |
Collapse
|
24
|
Gonzalez-Vicente A, Saez F, Monzon CM, Asirwatham J, Garvin JL. Thick Ascending Limb Sodium Transport in the Pathogenesis of Hypertension. Physiol Rev 2019; 99:235-309. [PMID: 30354966 DOI: 10.1152/physrev.00055.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The thick ascending limb plays a key role in maintaining water and electrolyte balance. The importance of this segment in regulating blood pressure is evidenced by the effect of loop diuretics or local genetic defects on this parameter. Hormones and factors produced by thick ascending limbs have both autocrine and paracrine effects, which can extend prohypertensive signaling to other structures of the nephron. In this review, we discuss the role of the thick ascending limb in the development of hypertension, not as a sole participant, but one that works within the rich biological context of the renal medulla. We first provide an overview of the basic physiology of the segment and the anatomical considerations necessary to understand its relationship with other renal structures. We explore the physiopathological changes in thick ascending limbs occurring in both genetic and induced animal models of hypertension. We then discuss the racial differences and genetic defects that affect blood pressure in humans through changes in thick ascending limb transport rates. Throughout the text, we scrutinize methodologies and discuss the limitations of research techniques that, when overlooked, can lead investigators to make erroneous conclusions. Thus, in addition to advancing an understanding of the basic mechanisms of physiology, the ultimate goal of this work is to understand our research tools, to make better use of them, and to contextualize research data. Future advances in renal hypertension research will require not only collection of new experimental data, but also integration of our current knowledge.
Collapse
Affiliation(s)
| | - Fara Saez
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Casandra M Monzon
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jessica Asirwatham
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, Case Western Reserve University , Cleveland, Ohio
| |
Collapse
|
25
|
Krawczyk KK, Skovsted GF, Perisic L, Dreier R, Berg JO, Hedin U, Rippe C, Swärd K. Expression of endothelin type B receptors (EDNRB) on smooth muscle cells is controlled by MKL2, ternary complex factors, and actin dynamics. Am J Physiol Cell Physiol 2018; 315:C873-C884. [PMID: 30332284 DOI: 10.1152/ajpcell.00170.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The endothelin type B receptor (ETB or EDNRB) is highly plastic and is upregulated in smooth muscle cells (SMCs) by arterial injury and following organ culture in vitro. We hypothesized that this transcriptional plasticity may arise, in part, because EDNRB is controlled by a balance of transcriptional inputs from myocardin-related transcription factors (MRTFs) and ternary complex factors (TCFs). We found significant positive correlations between the TCFs ELK3 and FLI1 versus EDNRB in human arteries. The MRTF MKL2 also correlated with EDNRB. Overexpression of ELK3, FLI1, and MKL2 in human coronary artery SMCs promoted expression of EDNRB, and the effect of MKL2 was antagonized by myocardin (MYOCD), which also correlated negatively with EDNRB at the tissue level. Silencing of MKL2 reduced basal EDNRB expression, but depolymerization of actin using latrunculin B (LatB) or overexpression of constitutively active cofilin, as well as treatment with the Rho-associated kinase (ROCK) inhibitor Y27632, increased EDNRB in a MEK/ERK-dependent fashion. Transcript-specific primers indicated that the second EDNRB transcript (EDNRB_2) was targeted, but this promoter was largely unresponsive to LatB and was inhibited rather than stimulated by MKL2 and FLI1, suggesting distant control elements or an indirect effect. LatB also reduced expression of endothelin-1, but supplementation experiments argued that this was not the cause of EDNRB induction. EDNRB finally changed in parallel with ELK3 and FLI1 in rat and human carotid artery lesions. These studies implicate the actin cytoskeleton and ELK3, FLI1, and MKL2 in the transcriptional control of EDNRB and increase our understanding of the plasticity of this receptor.
Collapse
Affiliation(s)
| | - Gry Freja Skovsted
- Department of Veterinary and Animal Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Ljubica Perisic
- Department of Molecular Medicine and Surgery, Karolinska Institutet , Stockholm , Sweden
| | - Rasmus Dreier
- Department of Medicine and Department of Clinical Physiology, Nuclear Medicine, and PET, University of Copenhagen, Herlev, Denmark
| | - Jais Oliver Berg
- Department of Plastic and Reconstructive Surgery, Herlev-Gentofte Hospital, University of Copenhagen, Herlev, Denmark
| | - Ulf Hedin
- Department of Molecular Medicine and Surgery, Karolinska Institutet , Stockholm , Sweden
| | - Catarina Rippe
- Department of Experimental Medical Science, Lund University , Lund , Sweden
| | - Karl Swärd
- Department of Experimental Medical Science, Lund University , Lund , Sweden
| |
Collapse
|
26
|
Vaněčková I, Hojná S, Kadlecová M, Vernerová Z, Kopkan L, Červenka L, Zicha J. Renoprotective effects of ET(A) receptor antagonists therapy in experimental non-diabetic chronic kidney disease: Is there still hope for the future? Physiol Res 2018; 67:S55-S67. [PMID: 29947528 DOI: 10.33549/physiolres.933898] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic kidney disease (CKD) is a life-threatening disease arising as a frequent complication of diabetes, obesity and hypertension. Since it is typically undetected for long periods, it often progresses to end-stage renal disease. CKD is characterized by the development of progressive glomerulosclerosis, interstitial fibrosis and tubular atrophy along with a decreased glomerular filtration rate. This is associated with podocyte injury and a progressive rise in proteinuria. As endothelin-1 (ET-1) through the activation of endothelin receptor type A (ET(A)) promotes renal cell injury, inflammation, and fibrosis which finally lead to proteinuria, it is not surprising that ET(A) receptors antagonists have been proven to have beneficial renoprotective effects in both experimental and clinical studies in diabetic and non-diabetic CKD. Unfortunately, fluid retention encountered in large clinical trials in diabetic CKD led to the termination of these studies. Therefore, several advances, including the synthesis of new antagonists with enhanced pharmacological activity, the use of lower doses of ET antagonists, the addition of diuretics, plus simply searching for distinct pathological states to be treated, are promising targets for future experimental studies. In support of these approaches, our group demonstrated in adult subtotally nephrectomized Ren-2 transgenic rats that the addition of a diuretic on top of renin-angiotensin and ET(A) blockade led to a further decrease of proteinuria. This effect was independent of blood pressure which was normalized in all treated groups. Recent data in non-diabetic CKD, therefore, indicate a new potential for ET(A) antagonists, at least under certain pathological conditions.
Collapse
Affiliation(s)
- I Vaněčková
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | | | | | | | | | | | | |
Collapse
|
27
|
Speed JS, Hyndman KA, Roth K, Heimlich JB, Kasztan M, Fox BM, Johnston JG, Becker BK, Jin C, Gamble KL, Young ME, Pollock JS, Pollock DM. High dietary sodium causes dyssynchrony of the renal molecular clock in rats. Am J Physiol Renal Physiol 2018; 314:F89-F98. [PMID: 28971988 PMCID: PMC5866350 DOI: 10.1152/ajprenal.00028.2017] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 08/31/2017] [Accepted: 09/22/2017] [Indexed: 11/22/2022] Open
Abstract
Speed JS, Hyndman KA, Roth K, Heimlich JB, Kasztan M, Fox BM, Johnston JG, Becker BK, Jin C, Gamble KL, Young ME, Pollock JS, Pollock DM. High dietary sodium causes dyssynchrony of the renal molecular clock in rats. Am J Physiol Renal Physiol 314: F89-F98, 2018. First published September 27, 2017; doi:10.1152/ajprenal.00028.2017.-Dyssynchrony of circadian rhythms is associated with various disorders, including cardiovascular and metabolic diseases. The cell autonomous molecular clock maintains circadian control; however, environmental factors that may cause circadian dyssynchrony either within or between organ systems are poorly understood. Our laboratory recently reported that the endothelin (ET-1) B (ETB) receptor functions to facilitate Na+ excretion in a time of day-dependent manner. Therefore, the present study was designed to determine whether high salt (HS) intake leads to circadian dyssynchrony within the kidney and whether the renal endothelin system contributes to control of the renal molecular clock. We observed that HS feeding led to region-specific alterations in circadian clock components within the kidney. For instance, HS caused a significant 5.5-h phase delay in the peak expression of Bmal1 and suppressed Cry1 and Per2 expression in the renal inner medulla, but not the renal cortex, of control rats. The phase delay in Bmal1 expression appears to be mediated by ET-1 because this phenomenon was not observed in the ETB-deficient rat. In cultured inner medullary collecting duct cells, ET-1 suppressed Bmal1 mRNA expression. Furthermore, Bmal1 knockdown in these cells reduced epithelial Na+ channel expression. These data reveal that HS feeding leads to intrarenal circadian dyssynchrony mediated, in part, through activation of ETB receptors within the renal inner medulla.
Collapse
Affiliation(s)
- Joshua S Speed
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Kelly A Hyndman
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Kaehler Roth
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | | | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Brandon M Fox
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Bryan K Becker
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Karen L Gamble
- Department of Psychiatry, University of Alabama at Birmingham , Birmingham, Alabama
| | - Martin E Young
- Department of Medicine, Division of Cardiovascular Disease, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jennifer S Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| |
Collapse
|
28
|
Speed JS, Hyndman KA, Kasztan M, Johnston JG, Roth KJ, Titze JM, Pollock DM. Diurnal pattern in skin Na + and water content is associated with salt-sensitive hypertension in ET B receptor-deficient rats. Am J Physiol Regul Integr Comp Physiol 2017; 314:R544-R551. [PMID: 29351432 DOI: 10.1152/ajpregu.00312.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Impairment in the ability of the skin to properly store Na+ nonosmotically (without water) has recently been hypothesized as contributing to salt-sensitive hypertension. Our laboratory has shown that endothelial production of endothelin-1 (ET-1) is crucial to skin Na+ handling. Furthermore, it is well established that loss of endothelin type B receptor (ETB) receptor function impairs Na+ excretion by the kidney. Thus we hypothesized that rats lacking functional ETB receptors (ETB-def) will have a reduced capacity of the skin to store Na+ during chronic high-salt (HS) intake. We observed that ETB-def rats exhibited salt-sensitive hypertension with an approximate doubling in the diurnal amplitude of mean arterial pressure compared with genetic control rats on a HS diet. Two weeks of HS diet significantly increased skin Na+ content relative to water; however, there was no significant difference between control and ETB-def rats. Interestingly, HS intake led to a 19% increase in skin Na+ and 16% increase in water content (relative to dry wt.) during the active phase (zeitgeber time 16) versus inactive phase (zeitgeber time 4, P < 0.05) in ETB-def rats. There was no significant circadian variation in total skin Na+ or water content of control rats fed normal or HS. These data indicate that ETB receptors have little influence on the ability to store Na+ nonosmotically in the skin during long-term HS intake but, rather, appear to regulate diurnal rhythms in skin Na+ content and circadian blood pressure rhythms associated with a HS diet.
Collapse
Affiliation(s)
- Joshua S Speed
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Kelly A Hyndman
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Kaehler J Roth
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Jens M Titze
- Cardiovasular and Metabolic Disorders, National University of Singapore Medical School, Singapore
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham , Birmingham, Alabama
| |
Collapse
|
29
|
Kansanen E, Kuosmanen SM, Ruotsalainen AK, Hynynen H, Levonen AL. Nitro-Oleic Acid Regulates Endothelin Signaling in Human Endothelial Cells. Mol Pharmacol 2017; 92:481-490. [DOI: 10.1124/mol.117.109751] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/02/2017] [Indexed: 11/22/2022] Open
|
30
|
Becker BK, Feagans AC, Chen D, Kasztan M, Jin C, Speed JS, Pollock JS, Pollock DM. Renal denervation attenuates hypertension but not salt sensitivity in ET B receptor-deficient rats. Am J Physiol Regul Integr Comp Physiol 2017; 313:R425-R437. [PMID: 28701323 DOI: 10.1152/ajpregu.00174.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/16/2017] [Accepted: 07/06/2017] [Indexed: 02/07/2023]
Abstract
Hypertension is a prevalent pathology that increases risk for numerous cardiovascular diseases. Because the etiology of hypertension varies across patients, specific and effective therapeutic approaches are needed. The role of renal sympathetic nerves is established in numerous forms of hypertension, but their contribution to salt sensitivity and interaction with factors such as endothelin-1 are poorly understood. Rats deficient of functional ETB receptors (ETB-def) on all tissues except sympathetic nerves are hypertensive and exhibit salt-sensitive increases in blood pressure. We hypothesized that renal sympathetic nerves contribute to hypertension and salt sensitivity in ETB-def rats. The hypothesis was tested through bilateral renal sympathetic nerve denervation and measuring blood pressure during normal salt (0.49% NaCl) and high-salt (4.0% NaCl) diets. Denervation reduced mean arterial pressure in ETB-def rats compared with sham-operated controls by 12 ± 3 (SE) mmHg; however, denervation did not affect the increase in blood pressure after 2 wk of high-salt diet (+19 ± 3 vs. +16 ± 3 mmHg relative to normal salt diet; denervated vs. sham, respectively). Denervation reduced cardiac sympathetic-to-parasympathetic tone [low frequency-high frequency (LF/HF)] during normal salt diet and vasomotor LF/HF tone during high-salt diet in ETB-def rats. We conclude that the renal sympathetic nerves contribute to the hypertension but not to salt sensitivity of ETB-def rats.
Collapse
Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Amanda C Feagans
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Daian Chen
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joshua S Speed
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jennifer S Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
31
|
Nickel NP, O'Leary JM, Brittain EL, Fessel JP, Zamanian RT, West JD, Austin ED. Kidney dysfunction in patients with pulmonary arterial hypertension. Pulm Circ 2017; 7:38-54. [PMID: 28680564 PMCID: PMC5448543 DOI: 10.1086/690018] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/26/2016] [Indexed: 12/19/2022] Open
Abstract
Pulmonary arterial hypertension (PH) and chronic kidney disease (CKD) both profoundly impact patient outcomes, whether as primary disease states or as co-morbid conditions. PH is a common co-morbidity in CKD and vice versa. A growing body of literature describes the epidemiology of PH secondary to chronic kidney disease and end-stage renal disease (ESRD) (WHO group 5 PH). But, there are only limited data on the epidemiology of kidney disease in group 1 PH (pulmonary arterial hypertension [PAH]). The purpose of this review is to summarize the current data on epidemiology and discuss potential disease mechanisms and management implications of kidney dysfunction in PAH. Kidney dysfunction, determined by serum creatinine or estimated glomerular filtration rate, is a frequent co-morbidity in PAH and impaired kidney function is a strong and independent predictor of mortality. Potential mechanisms of PAH affecting the kidneys are increased venous congestion, decreased cardiac output, and neurohormonal activation. On a molecular level, increased TGF-β signaling and increased levels of circulating cytokines could have the potential to worsen kidney function. Nephrotoxicity does not seem to be a common side effect of PAH-targeted therapy. Treatment implications for kidney disease in PAH include glycemic control, lifestyle modification, and potentially Renin-Angiotensin-Aldosterone System (RAAS) blockade.
Collapse
Affiliation(s)
- N P Nickel
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - J M O'Leary
- Division of Cardiovascular Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - E L Brittain
- Division of Cardiovascular Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - J P Fessel
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - R T Zamanian
- Division of Pulmonary and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - J D West
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - E D Austin
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
| |
Collapse
|
32
|
Vercauteren M, Trensz F, Pasquali A, Cattaneo C, Strasser DS, Hess P, Iglarz M, Clozel M. Endothelin ETA Receptor Blockade, by Activating ETB Receptors, Increases Vascular Permeability and Induces Exaggerated Fluid Retention. J Pharmacol Exp Ther 2017; 361:322-333. [DOI: 10.1124/jpet.116.234930] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/17/2017] [Indexed: 11/22/2022] Open
|
33
|
Gohar EY, Kasztan M, Pollock DM. Interplay between renal endothelin and purinergic signaling systems. Am J Physiol Renal Physiol 2017; 313:F666-F668. [PMID: 28179257 DOI: 10.1152/ajprenal.00639.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 12/19/2022] Open
Abstract
Alterations in extracellular fluid volume regulation and sodium balance may result in the development and maintenance of salt-dependent hypertension, a major risk factor for cardiovascular disease. Numerous pathways contribute to the regulation of sodium excretion and blood pressure, including endothelin and purinergic signaling. Increasing evidence suggests a link between purinergic receptor activation and endothelin production within the renal collecting duct as a means of promoting natriuresis. A better understanding of the relationship between these two systems, especially in regard to sodium homeostasis, will fill a significant knowledge gap and may provide novel antihypertensive treatment options. Therefore, this review focuses on the cross talk between endothelin and purinergic signaling as it relates to the renal regulation of sodium and blood pressure homeostasis.
Collapse
Affiliation(s)
- Eman Y Gohar
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Malgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
34
|
Functional ET(A)-ET(B) Receptor Cross-talk in Basilar Artery In Situ From ET(B) Receptor Deficient Rats. J Cardiovasc Pharmacol 2016; 67:212-7. [PMID: 26528589 DOI: 10.1097/fjc.0000000000000335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The role of endothelin (ET)(A)-ET(B) receptor cross-talk in limiting the ET(A) receptor antagonist inhibition of ET-1 constriction is revealed by the partial or complete dependency of the ET(A) receptor antagonist inhibition on functional removal of the ET(B) receptor. Although functional removal of the ET(B) receptor is generally accomplished with ET(B) receptor antagonist, a novel approach using rats containing a naturally occurring deletion mutation in the ET(B) receptor [rescued "spotting lethal" (sl) rats; ET(B)(sl/sl)] demonstrated increased ET(A) receptor antagonist inhibition of ET-1 constriction in vena cava. We investigated whether this deletion mutation was also sufficient to remove the ET(B) receptor dependency of the ET(A) receptor antagonist inhibition of ET-1 constriction in the basilar artery. Consistent with previous reports, ET-1 plasma levels were elevated in ET(B)(sl/sl) as compared with ET(B)(+/+) rats. ET(B) receptor antagonist failed to relax the ET-1 constricted basilar artery from ET(B)(+/+) and ET(B)(sl/sl) rats. Relaxation to combined ET(A) and ET(B) receptor antagonist was greater than relaxation to ET(A) receptor antagonist in the basilar artery from ET(B)(+/+) and, unexpectedly, ET(B)(sl/sl) rats. These findings confirm the presence of ET(A)-ET(B) receptor cross-talk in the basilar artery. We speculate that mutant ET(B) receptor expression produced by alternative splicing may be sufficient to allow cross-talk.
Collapse
|
35
|
Layton AT, Laghmani K, Vallon V, Edwards A. Solute transport and oxygen consumption along the nephrons: effects of Na+ transport inhibitors. Am J Physiol Renal Physiol 2016; 311:F1217-F1229. [PMID: 27707706 DOI: 10.1152/ajprenal.00294.2016] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/28/2016] [Indexed: 01/11/2023] Open
Abstract
Sodium and its associated anions are the major determinant of extracellular fluid volume, and the reabsorption of Na+ by the kidney plays a crucial role in long-term blood pressure control. The goal of this study was to investigate the extent to which inhibitors of transepithelial Na+ transport (TNa) along the nephron alter urinary solute excretion and TNa efficiency and how those effects may vary along different nephron segments. To accomplish that goal, we used the multinephron model developed in the companion study (28). That model represents detailed transcellular and paracellular transport processes along the nephrons of a rat kidney. We simulated the inhibition of the Na+/H+ exchanger (NHE3), the bumetanide-sensitive Na+-K+-2Cl- transporter (NKCC2), the Na+-Cl- cotransporter (NCC), and the amiloride-sensitive Na+ channel (ENaC). Under baseline conditions, NHE3, NKCC2, NCC, and ENaC reabsorb 36, 22, 4, and 7%, respectively, of filtered Na+ The model predicted that inhibition of NHE3 substantially reduced proximal tubule TNa and oxygen consumption (QO2 ). Whole-kidney TNa efficiency, as reflected by the number of moles of Na+ reabsorbed per moles of O2 consumed (denoted by the ratio TNa/QO2 ), decreased by ∼20% with 80% inhibition of NHE3. NKCC2 inhibition simulations predicted a substantial reduction in thick ascending limb TNa and QO2 ; however, the effect on whole-kidney TNa/QO2 was minor. Tubular K+ transport was also substantially impaired, resulting in elevated urinary K+ excretion. The most notable effect of NCC inhibition was to increase the excretion of Na+, K+, and Cl-; its impact on whole-kidney TNa and its efficiency was minor. Inhibition of ENaC was predicted to have opposite effects on the excretion of Na+ (increased) and K+ (decreased) and to have only a minor impact on whole-kidney TNa and TNa/QO2 Overall, model predictions agree well with measured changes in Na+ and K+ excretion in response to diuretics and Na+ transporter mutations.
Collapse
Affiliation(s)
- Anita T Layton
- Department of Mathematics, Duke University, Durham, North Carolina;
| | - Kamel Laghmani
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and
| | - Volker Vallon
- Departments of Medicine and Pharmacology, University of California San Diego, La Jolla, California, and San Diego Veterans Affairs Healthcare System, San Diego, California
| | - Aurélie Edwards
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and
| |
Collapse
|
36
|
Johnston JG, Speed JS, Jin C, Pollock DM. Loss of endothelin B receptor function impairs sodium excretion in a time- and sex-dependent manner. Am J Physiol Renal Physiol 2016; 311:F991-F998. [PMID: 27582096 DOI: 10.1152/ajprenal.00103.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 08/27/2016] [Indexed: 12/28/2022] Open
Abstract
Recent studies suggested a direct link between circadian rhythms and regulation of sodium excretion. Endothelin-1 (ET-1) regulates sodium balance by promoting natriuresis through the endothelin B receptor (ETB) in response to increased salt in the diet, but the effect that the time of day has on this natriuretic response is not known. Therefore, this study was designed to test the hypothesis that ETB receptor activation contributes to the diurnal control of sodium excretion and that sex differences contribute to this control as well. Twelve-hour urine collections were used to measure sodium excretion. On day 3 of the experiment, a NaCl load (900 μeq) was given by oral gavage either at Zeitgeber time [ZT] 0 (inactive period) or ZT12 (active period) to examine the natriuretic response to the acute salt load. Male and female ETB-deficient (ETB def) rats showed an impaired natriuretic response to a salt load at ZT0 compared with their respective transgenic controls (Tg cont). Male ETB def rats showed a delayed natriuretic response to a salt load given at ZT12 compared with male Tg cont, a contrast to the prompt response shown by female ETB def rats. Treatment with ABT-627, an ETA receptor antagonist, improved the natriuretic response seen within the first 12 h of a ZT0 salt load in both sexes. These findings demonstrate that diurnal excretion of an acute salt load 1) requires ET-1 and the ETB receptor, 2) is more evident in male vs. female rats, and 3) is opposed by the ETA receptor.
Collapse
Affiliation(s)
- Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joshua S Speed
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
37
|
Elijovich F, Weinberger MH, Anderson CAM, Appel LJ, Bursztyn M, Cook NR, Dart RA, Newton-Cheh CH, Sacks FM, Laffer CL. Salt Sensitivity of Blood Pressure: A Scientific Statement From the American Heart Association. Hypertension 2016; 68:e7-e46. [PMID: 27443572 DOI: 10.1161/hyp.0000000000000047] [Citation(s) in RCA: 301] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
38
|
Akashi K, Saegusa J, Sendo S, Nishimura K, Okano T, Yagi K, Yanagisawa M, Emoto N, Morinobu A. Knockout of endothelin type B receptor signaling attenuates bleomycin-induced skin sclerosis in mice. Arthritis Res Ther 2016; 18:113. [PMID: 27209208 PMCID: PMC4875589 DOI: 10.1186/s13075-016-1011-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 05/03/2016] [Indexed: 02/07/2023] Open
Abstract
Background Endothelin-1 (ET-1) is important in the pathogenesis of systemic sclerosis (SSc). ET-1 binds two receptors, endothelin type A (ETA) and endothelin type B (ETB). Dual ETA/ETB receptor antagonists and a selective ETA receptor antagonist are used clinically to treat SSc, and the effect of these antagonists on fibroblast activation has been described. However, the role of ETB receptor signaling in fibrogenesis is less clear. This study was conducted to evaluate the profibrotic function of ETB receptor signaling in a murine model of bleomycin (BLM)-induced scleroderma. Methods We used ETB receptor–knockout (ETBKO) mice, which are genetically rescued from lethal intestinal aganglionosis by an ETB receptor transgene driven by the human dopamine β-hydroxylase (DβH)-gene promoter, and wild-type mice with DβH-ETB (WT). BLM or phosphate-buffered saline (PBS) was administered subcutaneously by osmotic minipump, and skin fibrosis was assessed by dermal thickness, subcutaneous fat atrophy, and myofibroblast count in the dermis. Dermal fibroblasts isolated from ETBKO and WT mice were cultured in vitro, stimulated with BLM or ET-1, and the expression of profibrotic genes was compared by quantitative PCR. Results Dermal thickness, subcutaneous fat atrophy, and myofibroblast counts in the dermis were significantly reduced in ETBKO mice compared to WT mice, after BLM treatment. Compared with wild-type, dermal fibroblasts isolated from ETBKO mice showed lower gene expressions of α-smooth muscle actin and collagen 1α1 in response to BLM or ET-1 stimulation in vitro. Conclusions ET-1–ETB receptor signaling is involved in skin sclerosis and in collagen synthesis by dermal fibroblasts. Electronic supplementary material The online version of this article (doi:10.1186/s13075-016-1011-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kengo Akashi
- Department of Rheumatology and Clinical Immunology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Jun Saegusa
- Department of Rheumatology and Clinical Immunology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Sho Sendo
- Department of Rheumatology and Clinical Immunology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Keisuke Nishimura
- Department of Rheumatology and Clinical Immunology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan
| | - Takuya Okano
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe, Japan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Keiko Yagi
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Japan
| | - Noriaki Emoto
- Department of Clinical Pharmacy, Kobe Pharmaceutical University, Kobe, Japan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Akio Morinobu
- Department of Rheumatology and Clinical Immunology, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
| |
Collapse
|
39
|
Srisawat U, Kongrat S, Muanprasat C, Chatsudthipong V. Losartan and Sodium Nitroprusside Effectively Protect against Renal Impairments after Ischemia and Reperfusion in Rats. Biol Pharm Bull 2016; 38:753-62. [PMID: 25947921 DOI: 10.1248/bpb.b14-00860] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ischemia and subsequent reperfusion are known to impair renal function. We examined several agents that might prevent renal impairment or enhance the recovery of renal function after ischemia/reperfusion injury in rats. Different degrees of preventive effects were observed in rats treated with captopril, BQ-123 (endothelin type A receptor antagonist), sodium nitroprusside (SNP, a nitric oxide donor), and losartan (angiotensin II type 1 receptor antagonist). Only minimal changes in renal morphology were observed after treatment with losartan, SNP, captopril, and BQ-123 compared with control animals. On the other hand, lesions were prominent in the N(G)-nitro-L-arginine-methyl ester (L-NAME)- and L-arginine-treated rats. The Na(+)-K(+) ATPase activity of ischemic kidneys was, however, preserved in all treatment groups, except in those treated with L-arginine and L-NAME, which showed a marked reduction in Na(+)-K(+) ATPase activity. Our post-treatment data suggest that losartan and SNP have the greatest potential for therapeutic use to mitigate post-ischemic renal damage and functional impairment.
Collapse
Affiliation(s)
- Umarat Srisawat
- Department of Physiology, Faculty of Science, Mahidol University
| | | | | | | |
Collapse
|
40
|
Davenport AP, Hyndman KA, Dhaun N, Southan C, Kohan DE, Pollock JS, Pollock DM, Webb DJ, Maguire JJ. Endothelin. Pharmacol Rev 2016; 68:357-418. [PMID: 26956245 PMCID: PMC4815360 DOI: 10.1124/pr.115.011833] [Citation(s) in RCA: 462] [Impact Index Per Article: 57.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The endothelins comprise three structurally similar 21-amino acid peptides. Endothelin-1 and -2 activate two G-protein coupled receptors, ETA and ETB, with equal affinity, whereas endothelin-3 has a lower affinity for the ETA subtype. Genes encoding the peptides are present only among vertebrates. The ligand-receptor signaling pathway is a vertebrate innovation and may reflect the evolution of endothelin-1 as the most potent vasoconstrictor in the human cardiovascular system with remarkably long lasting action. Highly selective peptide ETA and ETB antagonists and ETB agonists together with radiolabeled analogs have accurately delineated endothelin pharmacology in humans and animal models, although surprisingly no ETA agonist has been discovered. ET antagonists (bosentan, ambrisentan) have revolutionized the treatment of pulmonary arterial hypertension, with the next generation of antagonists exhibiting improved efficacy (macitentan). Clinical trials continue to explore new applications, particularly in renal failure and for reducing proteinuria in diabetic nephropathy. Translational studies suggest a potential benefit of ETB agonists in chemotherapy and neuroprotection. However, demonstrating clinical efficacy of combined inhibitors of the endothelin converting enzyme and neutral endopeptidase has proved elusive. Over 28 genetic modifications have been made to the ET system in mice through global or cell-specific knockouts, knock ins, or alterations in gene expression of endothelin ligands or their target receptors. These studies have identified key roles for the endothelin isoforms and new therapeutic targets in development, fluid-electrolyte homeostasis, and cardiovascular and neuronal function. For the future, novel pharmacological strategies are emerging via small molecule epigenetic modulators, biologicals such as ETB monoclonal antibodies and the potential of signaling pathway biased agonists and antagonists.
Collapse
Affiliation(s)
- Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Kelly A Hyndman
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Neeraj Dhaun
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Christopher Southan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Donald E Kohan
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Jennifer S Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David M Pollock
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - David J Webb
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Cambridge, United Kingdom (A.P.D., J.J.M.); IUPHAR/BPS Guide to PHARMACOLOGY, Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, Edinburgh, United Kingdom (C.S.); Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah (D.E.K.); Cardio-Renal Physiology & Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama (K.A.H., J.S.P., D.M.P.); and Department of Renal Medicine, Royal Infirmary of Edinburgh (N.D.) and University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute (D.J.W.N.D.), Edinburgh, Scotland, United Kingdom
| |
Collapse
|
41
|
Abstract
All three members of the endothelin (ET) family of peptides, ET-1, ET-2, and ET-3, are expressed in the human kidney, with ET-1 being the predominant isoform. ET-1 and ET-2 bind to two G-protein–coupled receptors, ETA and ETB, whereas at physiological concentrations ET-3 has little affinity for the ETA receptor. The human kidney is unusual among the peripheral organs in expressing a high density of ETB. The renal vascular endothelium only expresses the ETB subtype and ET-1 acts in an autocrine or paracrine manner to release vasodilators. Endothelial ETB in kidney, as well as liver and lungs, also has a critical role in scavenging ET-1 from the plasma. The third major function is ET-1 activation of ETB in in the nephron to reduce salt and water re-absorption. In contrast, ETA predominate on smooth muscle, causing vasoconstriction and mediating many of the pathophysiological actions of ET-1. The role of the two receptors has been delineated using highly selective ETA (BQ123, TAK-044) and ETB (BQ788) peptide antagonists. Nonpeptide antagonists, bosentan, macitentan, and ambrisentan, that are either mixed ETA/ETB antagonists or display ETA selectivity, have been approved for clinical use but to date are limited to pulmonary hypertension. Ambrisentan is in clinical trials in patients with type 2 diabetic nephropathy. This review summarizes ET-receptor antagonism in the human kidney, and considers the relative merits of selective versus nonselective antagonism in renal disease.
Collapse
|
42
|
Aversa M, Porter S, Granton J. Comparative safety and tolerability of endothelin receptor antagonists in pulmonary arterial hypertension. Drug Saf 2016; 38:419-35. [PMID: 25792028 DOI: 10.1007/s40264-015-0275-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pulmonary arterial hypertension (PAH) is a condition that leads to progressive right heart failure and death unless recognized and treated early. Endothelin, a potent endogenous vasoconstrictor, has been identified as an important mediator of PAH. Endothelin receptor antagonists (ERAs) have been associated with an improvement in exercise capacity and time to clinical worsening in patients with Group 1 PAH, and three different ERAs are currently approved for use in this population: bosentan, ambrisentan, and macitentan. While all three ERAs are generally well-tolerated, they each have important adverse effects that need to be recognized and monitored. In particular, they may cause anemia, peripheral edema, and mild cardiac, respiratory, neurologic, and gastrointestinal adverse effects to varying degrees. Although bosentan increases a patient's risk of developing liver transaminitis, ambrisentan and macitentan do not appear to confer the same risk of hepatotoxicity at this time. Important drug-drug interactions, particularly involving other drugs metabolized via the cytochrome P450 pathway, are important to recognize when prescribing ERAs. In this review, we provide a brief overview of the current state of knowledge as it relates to the adverse effect profiles, tolerability, and drug-drug interactions of this class of medication as informed by the results of randomized clinical trials, drug surveillance programs, and regulatory agencies.
Collapse
Affiliation(s)
- Meghan Aversa
- Toronto General Hospital, 11-124 Munk building, 585 University Ave, Toronto, Ontario, Canada
| | | | | |
Collapse
|
43
|
Saleh L, Verdonk K, Visser W, van den Meiracker AH, Danser AHJ. The emerging role of endothelin-1 in the pathogenesis of pre-eclampsia. Ther Adv Cardiovasc Dis 2016; 10:282-93. [PMID: 26755746 DOI: 10.1177/1753944715624853] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Pre-eclampsia (PE) is the most frequently encountered medical complication during pregnancy. It is characterized by a rise in systemic vascular resistance with a relatively low cardiac output and hypovolemia, combined with severe proteinuria. Despite the hypovolemia, renin-angiotensin system (RAS) activity is suppressed and aldosterone levels are decreased to the same degree as renin. This suggests that the RAS is not the cause of the hypertension in PE, but rather that its suppression is the consequence of the rise in blood pressure. Abnormal placentation early in pregnancy is widely assumed to be an important initial event in the onset of PE. Eventually, this results in the release of anti-angiogenic factors [in particular, soluble Fms-like tyrosine kinase-1 (sFlt-1)] and cytokines, leading to generalized vascular dysfunction. Elevated sFlt-1 levels bind and inactivate vascular endothelial growth factor (VEGF). Of interest, VEGF inhibition with drugs like sunitinib, applied in cancer patients, results in a PE-like syndrome, characterized by hypertension, proteinuria and renal toxicity. Both in cancer patients treated with sunitinib and in pregnant women with PE, significant rises in endothelin-1 occur. Multiple regression analysis revealed that endothelin-1 is an independent determinant of the hypertension and proteinuria in PE, and additionally a renin suppressor. Moreover, studies in animal models representative of PE, have shown that endothelin receptor blockers prevent the development of this disease. Similarly, endothelin receptor blockers are protective during sunitinib treatment. Taken together, activation of the endothelin system emerges as an important pathway causing the clinical manifestations of PE. This paper critically addresses this concept, taking into consideration both clinical and preclinical data, and simultaneously discusses the therapeutic consequences of this observation.
Collapse
Affiliation(s)
- Langeza Saleh
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The NetherlandsDivision Obstetrics & Prenatal Medicine, Department of Obstetrics & Gynaecology, Erasmus MC, Rotterdam, The Netherlands
| | - Koen Verdonk
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Willy Visser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The NetherlandsDivision Obstetrics & Prenatal Medicine, Department of Obstetrics & Gynaecology, Erasmus MC, Rotterdam, The Netherlands
| | - Anton H van den Meiracker
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - A H Jan Danser
- Department of Internal Medicine, Division of Vascular Medicine & Pharmacology, Room EE1418, Erasmus MC, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
| |
Collapse
|
44
|
Jin C, Speed JS, Pollock DM. High salt intake increases endothelin B receptor function in the renal medulla of rats. Life Sci 2015; 159:144-147. [PMID: 26724217 DOI: 10.1016/j.lfs.2015.12.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 11/15/2022]
Abstract
AIMS Endothelin (ET)-1 promotes natriuresis via the endothelin B receptor (ETB) within the renal medulla. In male rats, direct interstitial infusion of ET-1 into the renal medulla has no effect on renal sodium and water excretion but is associated with endothelin A receptor (ETA)-dependent reductions in medullary blood flow. Loss of ETB function leads to salt-sensitive hypertension. We hypothesized that HS intake would increase the natriuretic and diuretic response to renal medullary infusion of ET peptides. MAIN METHODS Male Sprague-Dawley (SD) rats were fed a normal (NS) or high (HS) salt diet for 7days. Rats were anesthetized and a catheter implanted in the renal medulla for interstitial infusion along with a ureteral catheter for urine collection. Medullary infusion of a low dose of ETB receptor agonist, sarafotoxin 6c (S6c; 0.15μg/kg/h), or ET-1 (0.45μg/kg/h) was used to determine changes in sodium excretion (UNaV). KEY FINDINGS In HS fed rats, intramedullary infusion of a low dose of S6c induced a significant increase in UNaV, roughly 2-fold over baseline, compared to no response to this low dose in NS fed rats. In HS fed rats, intramedullary infusion of ET-1 induced a significantly greater increase in UNaV compared to NS fed rats, although this increase was not different from the HS time control studies. SIGNIFICANCE We conclude that high salt intake enhances the diuretic and natriuretic effects of ETB receptor activation in vivo consistent with a role for the ETB receptor in maintaining fluid-electrolyte homeostasis.
Collapse
Affiliation(s)
- Chunhua Jin
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Joshua S Speed
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States.
| |
Collapse
|
45
|
De Miguel C, Pollock DM, Pollock JS. Endothelium-derived ET-1 and the development of renal injury. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1071-3. [PMID: 25994955 DOI: 10.1152/ajpregu.00142.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 05/04/2015] [Indexed: 01/24/2023]
Abstract
The role of the vasoactive peptide endothelin-1 (ET-1) in renal injury is not fully understood. In this review, we examine the genetic models available to understand the autocrine/paracrine mechanisms by which ET-1 leads to renal injury and propose the working hypothesis that endothelium-derived ET-1 induces renal injury by initiating renal tubular apoptosis in a paracrine manner.
Collapse
Affiliation(s)
- Carmen De Miguel
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David M Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jennifer S Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
46
|
Abstract
The amiloride-sensitive epithelial Na(+) channel (ENaC) is a key player in the regulation of Na(+) homeostasis. Its functional activity is under continuous control by a variety of signaling molecules, including bioactive peptides of endothelin family. Since ENaC dysfunction is causative for disturbances in total body Na(+) levels associated with the abnormal regulation of blood volume, blood pressure, and lung fluid balance, uncovering the molecular mechanisms of inhibitory modulation or inappropriate activation of ENaC is crucial for the successful treatment of a variety of human diseases including hypertension. The precise regulation of ENaC is particularly important for normal Na(+) and fluid homeostasis in organs where endothelins are known to act: the kidneys, lung, and colon. Inhibition of ENaC by endothelin-1 (ET-1) has been established in renal cells, and several molecular mechanisms of inhibition of ENaC by ET-1 are proposed and will be reviewed in this chapter.
Collapse
Affiliation(s)
- Andrey Sorokin
- Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
| | | |
Collapse
|
47
|
Kolettis TM, Kontonika M, Barka E, Daskalopoulos EP, Baltogiannis GG, Tourmousoglou C, Papalois A, Kyriakides ZS. Central Sympathetic Activation and Arrhythmogenesis during Acute Myocardial Infarction: Modulating Effects of Endothelin-B Receptors. Front Cardiovasc Med 2015; 2:6. [PMID: 26664878 PMCID: PMC4671362 DOI: 10.3389/fcvm.2015.00006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/10/2015] [Indexed: 12/15/2022] Open
Abstract
Sympathetic activation during acute myocardial infarction (MI) is an important arrhythmogenic mechanism, but the role of central autonomic inputs and their modulating factors remain unclear. Using the in vivo rat-model, we examined the effects of clonidine, a centrally acting sympatholytic agent, in the presence or absence of myocardial endothelin-B (ETB) receptors. We studied wild-type (n = 20) and ETB-deficient rats (n = 20) after permanent coronary ligation, with or without pretreatment with clonidine. Cardiac rhythm was continuously recorded for 24 h by implantable telemetry devices, coupled by the assessment of autonomic and heart failure indices. Sympathetic activation and arrhythmogenesis were more prominent in ETB-deficient rats during the early phase post-ligation. Clonidine improved these outcomes throughout the observation period in ETB-deficient rats, but only during the delayed phase in wild-type rats. However, this benefit was counterbalanced by atrioventricular conduction abnormalities and by higher incidence of heart failure, the latter particularly evident in ETB-deficient rats. Myocardial ETB-receptors attenuate the arrhythmogenic effects of central sympathetic activation during acute MI. ETB-receptor deficiency potentiates the sympatholytic effects of clonidine and aggravates heart failure. The interaction between endothelin and sympathetic responses during myocardial ischemia/infarction and its impact on arrhythmogenesis and left ventricular dysfunction merits further investigation.
Collapse
Affiliation(s)
| | | | - Eleonora Barka
- Cardiovascular Research Institute , Ioannina and Athens , Greece
| | | | | | | | - Apostolos Papalois
- Cardiovascular Research Institute , Ioannina and Athens , Greece ; Experimental Research Center ELPEN , Athens , Greece
| | | |
Collapse
|
48
|
Zicha J, Dobešová Z, Zídek V, Silhavý J, Simáková M, Mlejnek P, Vaněčková I, Kuneš J, Pravenec M. Pharmacogenetic analysis of captopril effects on blood pressure: possible role of the Ednrb (endothelin receptor type B) candidate gene. Physiol Res 2015; 63:263-5. [PMID: 24779608 DOI: 10.33549/physiolres.932732] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The objective of the current study was to search for genetic determinants associated with antihypertensive effects of angiotensin-converting enzyme (ACE) inhibitor captopril. Linkage and correlation analyses of captopril-induced effects on blood pressure (BP) with renal transcriptome were performed in the BXH/HXB recombinant inbred (RI) strains derived from spontaneously hypertensive rat (SHR) and Brown Norway (BN-Lx) progenitors. Variability of blood pressure lowering effects of captopril among RI strains was continuous suggesting a polygenic mode of inheritance. Linkage analysis of captopril-induced BP effects revealed a significant quantitative trait locus (QTL) on chromosome 15. This QTL colocalized with cis regulated expression QTL (eQTL) for the Ednrb (endothelin receptor type B) gene in the kidney (SHR allele was associated with increased renal expression) and renal expression of Ednrb correlated with captopril-induced BP effects. These results suggest that blood pressure lowering effects of ACE inhibitor captopril may be modulated by the variants at the Ednrb locus.
Collapse
Affiliation(s)
- J Zicha
- Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kopp UC. Role of renal sensory nerves in physiological and pathophysiological conditions. Am J Physiol Regul Integr Comp Physiol 2015; 308:R79-95. [PMID: 25411364 PMCID: PMC4297860 DOI: 10.1152/ajpregu.00351.2014] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 11/02/2014] [Indexed: 12/26/2022]
Abstract
Whether activation of afferent renal nerves contributes to the regulation of arterial pressure and sodium balance has been long overlooked. In normotensive rats, activating renal mechanosensory nerves decrease efferent renal sympathetic nerve activity (ERSNA) and increase urinary sodium excretion, an inhibitory renorenal reflex. There is an interaction between efferent and afferent renal nerves, whereby increases in ERSNA increase afferent renal nerve activity (ARNA), leading to decreases in ERSNA by activation of the renorenal reflexes to maintain low ERSNA to minimize sodium retention. High-sodium diet enhances the responsiveness of the renal sensory nerves, while low dietary sodium reduces the responsiveness of the renal sensory nerves, thus producing physiologically appropriate responses to maintain sodium balance. Increased renal ANG II reduces the responsiveness of the renal sensory nerves in physiological and pathophysiological conditions, including hypertension, congestive heart failure, and ischemia-induced acute renal failure. Impairment of inhibitory renorenal reflexes in these pathological states would contribute to the hypertension and sodium retention. When the inhibitory renorenal reflexes are suppressed, excitatory reflexes may prevail. Renal denervation reduces arterial pressure in experimental hypertension and in treatment-resistant hypertensive patients. The fall in arterial pressure is associated with a fall in muscle sympathetic nerve activity, suggesting that increased ARNA contributes to increased arterial pressure in these patients. Although removal of both renal sympathetic and afferent renal sensory nerves most likely contributes to the arterial pressure reduction initially, additional mechanisms may be involved in long-term arterial pressure reduction since sympathetic and sensory nerves reinnervate renal tissue in a similar time-dependent fashion following renal denervation.
Collapse
Affiliation(s)
- Ulla C Kopp
- Departments of Internal Medicine and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| |
Collapse
|
50
|
Endothelin A receptor blocker atrasentan lowers blood pressure by the reduction of nifedipine-sensitive calcium influx in Ren-2 transgenic rats fed a high-salt diet. J Hypertens 2015; 33:161-9. [DOI: 10.1097/hjh.0000000000000357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|