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Lenzini L, Caroccia B, Seccia TM, Rossi GP. Peptidergic G Protein-Coupled Receptor Regulation of Adrenal Function: Bench to Bedside and Back. Endocr Rev 2022; 43:1038-1050. [PMID: 35436330 DOI: 10.1210/endrev/bnac011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Indexed: 11/19/2022]
Abstract
An altered secretion of adrenocortical and adrenomedullary hormones plays a role in the clinical syndromes of primary aldosteronism (PA), Cushing, and pheochromocytoma. Moreover, an altered production of adrenocortical hormones and/or an abnormal release of factors by the adrenal medulla are involved in several other diseases, including high blood pressure, congestive heart failure, liver cirrhosis, nephrotic syndrome, primary reninism, renovascular hypertension, Addison disease, Bartter, Gitelman, and virilization syndromes. Understanding the regulation of adrenal function and the interactions between adrenal cortex and medulla is, therefore, the prerequisite for mechanistic understanding of these disorders. Accumulating evidence indicates that the modulation of adrenal hormone biosynthesis is a process far more complex than originally thought, as it involves several factors, each cooperating with the other. Moreover, the tight vascular and neural interconnections between the adrenal cortex and medulla underlie physiologically relevant autocrine/paracrine interactions involving several peptides. Besides playing a pathophysiological role in common adrenal diseases, these complex mechanisms could intervene also in rare diseases, such as pheochromocytoma concomitant with adrenal Cushing or with PA, and PA co-occurring with Cushing, through mechanisms that remain to be fully understood at the molecular levels. Heterodimerization of G protein-coupled receptors (GPCRs) induced by peptide signaling is a further emerging new modulatory mechanism capable of finely tuning adrenal hormones synthesis and release. In this review we will examine current knowledge on the role of peptides that act via GPCRs in the regulation of adrenal hormone secretion with a particular focus on autocrine-paracrine signals.
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Affiliation(s)
- Livia Lenzini
- Emergency Medicine Unit, Center for blood pressure disorders -Regione Veneto and Specialized Center of Excellence for Hypertension of the European Society of Hypertension, Department of Medicine-DIMED, University of Padua, 35126 Padua, Italy
| | - Brasilina Caroccia
- Emergency Medicine Unit, Center for blood pressure disorders -Regione Veneto and Specialized Center of Excellence for Hypertension of the European Society of Hypertension, Department of Medicine-DIMED, University of Padua, 35126 Padua, Italy
| | - Teresa Maria Seccia
- Emergency Medicine Unit, Center for blood pressure disorders -Regione Veneto and Specialized Center of Excellence for Hypertension of the European Society of Hypertension, Department of Medicine-DIMED, University of Padua, 35126 Padua, Italy
| | - Gian Paolo Rossi
- Emergency Medicine Unit, Center for blood pressure disorders -Regione Veneto and Specialized Center of Excellence for Hypertension of the European Society of Hypertension, Department of Medicine-DIMED, University of Padua, 35126 Padua, Italy
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Rossi GP, Lenzini L, Caroccia B, Rossitto G, Seccia TM. Angiotensin peptides in the regulation of adrenal cortical function. EXPLORATION OF MEDICINE 2021. [DOI: 10.37349/emed.2021.00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The adrenal cortex plays a key role in the regulation of metabolism, salt and water homeostasis and sex differentiation by synthesizing glucocorticoid, mineralocorticoid and androgen hormones. Evidence exists that angiotensin II regulates adrenocortical function and it has been contended that angiotensin peptides of the non-canonical branch of the renin angiotensin system (RAS) might also modulate steroidogenesis in adrenals. Thus, the aim of this review is to examine the role of the RAS, and particularly of the angiotensin peptides and their receptors, in the regulation of adrenocortical hormones with particular focus on aldosterone production.
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Affiliation(s)
- Gian Paolo Rossi
- Emergency Medicine Unit and European Society of Hypertension Specialized Center of Excellence for Hypertension, Department of Medicine-DIMED, University of Padua, Italy
| | - Livia Lenzini
- Emergency Medicine Unit and European Society of Hypertension Specialized Center of Excellence for Hypertension, Department of Medicine-DIMED, University of Padua, Italy
| | - Brasilina Caroccia
- Emergency Medicine Unit and European Society of Hypertension Specialized Center of Excellence for Hypertension, Department of Medicine-DIMED, University of Padua, Italy
| | - Giacomo Rossitto
- Emergency Medicine Unit and European Society of Hypertension Specialized Center of Excellence for Hypertension, Department of Medicine-DIMED, University of Padua, Italy
| | - Teresa Maria Seccia
- Emergency Medicine Unit and European Society of Hypertension Specialized Center of Excellence for Hypertension, Department of Medicine-DIMED, University of Padua, Italy
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Endothelin-1 role in human eye: a review. J Ophthalmol 2011; 2010:354645. [PMID: 21461356 PMCID: PMC3065050 DOI: 10.1155/2010/354645] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 11/14/2010] [Accepted: 12/13/2010] [Indexed: 12/05/2022] Open
Abstract
Endothelin is a potent vasoactive peptide occurring in three isotypes, ET-1, ET-2, and ET-3. Through its two main receptors, endothelin A and endothelin B, it is responsible for a variety of physiological functions, primarily blood flow control. Recent evidence from both human and animal models shows involvement of endothelin in diabetes, retinal circulation, and optic neuropathies. Increased circulating levels of endothelin-1 (ET-1) have been found in patients with diabetes, and a positive correlation between plasma ET-1 levels and microangiopathy in patients with type-2 diabetes has been demonstrated. In addition to its direct vasoconstrictor effects, enhanced levels of ET-1 may contribute to endothelial dysfunction through inhibitory effects on nitric oxide (NO) production. Experimental studies have shown that chronic ET-1 administration to the optic nerve immediately behind the globe causes neuronal damage, activation of astrocytes, the major glial cell in the anterior optic nerve, and upregulation of endothelin B receptors. This paper outlines the ubiquitous role of endothelin and its potential involvement in ophthalmology.
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Bourque SL, Davidge ST, Adams MA. The interaction between endothelin-1 and nitric oxide in the vasculature: new perspectives. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1288-95. [PMID: 21368267 DOI: 10.1152/ajpregu.00397.2010] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) and endothelin-1 (ET-1) are natural counterparts in vascular function, and it is becoming increasingly clear that an imbalance between these two mediators is a characteristic of endothelial dysfunction and is important in the progression of vascular disease. Here, we review classical and more recent data that suggest that ET-1 should be regarded as an essential component of NO signaling. In particular, we review evidence of the role of ET-1 in models of acute and chronic NO synthase blockade. Furthermore, we discuss the possible mechanisms by which NO modulates ET-1 activity. On the basis of these studies, we suggest that NO tonically inhibits ET-1 function, and in conditions of diminished NO bioavailability, the deleterious effects of unmitigated ET-1 actions result in vasoconstriction and eventually lead to vascular remodeling and dysfunction.
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Affiliation(s)
- Stephane L Bourque
- Department of Obstetrics and Gynaecology, University of Alberta, Edmonton, Canada
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Kohan DE, Rossi NF, Inscho EW, Pollock DM. Regulation of blood pressure and salt homeostasis by endothelin. Physiol Rev 2011; 91:1-77. [PMID: 21248162 DOI: 10.1152/physrev.00060.2009] [Citation(s) in RCA: 291] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endothelin (ET) peptides and their receptors are intimately involved in the physiological control of systemic blood pressure and body Na homeostasis, exerting these effects through alterations in a host of circulating and local factors. Hormonal systems affected by ET include natriuretic peptides, aldosterone, catecholamines, and angiotensin. ET also directly regulates cardiac output, central and peripheral nervous system activity, renal Na and water excretion, systemic vascular resistance, and venous capacitance. ET regulation of these systems is often complex, sometimes involving opposing actions depending on which receptor isoform is activated, which cells are affected, and what other prevailing factors exist. A detailed understanding of this system is important; disordered regulation of the ET system is strongly associated with hypertension and dysregulated extracellular fluid volume homeostasis. In addition, ET receptor antagonists are being increasingly used for the treatment of a variety of diseases; while demonstrating benefit, these agents also have adverse effects on fluid retention that may substantially limit their clinical utility. This review provides a detailed analysis of how the ET system is involved in the control of blood pressure and Na homeostasis, focusing primarily on physiological regulation with some discussion of the role of the ET system in hypertension.
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Affiliation(s)
- Donald E Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
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Matsumoto T, Kakami M, Kobayashi T, Kamata K. Gender differences in vascular reactivity to endothelin-1 (1-31) in mesenteric arteries from diabetic mice. Peptides 2008; 29:1338-46. [PMID: 18486991 DOI: 10.1016/j.peptides.2008.04.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 04/01/2008] [Accepted: 04/03/2008] [Indexed: 01/22/2023]
Abstract
Endothelin-1 (1-31) [ET-1 (1-31)], a novel member of the ET family, comprises 31 amino acids and is derived from the selective hydrolysis of big ET-1 by chymase. Although ET-1 (1-31) reportedly exerts biological effects by direct or indirect [via its conversion to ET-1 (1-21)] mechanisms, it is unclear whether in diabetes the vascular effects of ET-1 (1-31) display gender differences. We investigated this question by exposing mesenteric artery rings to ET-1 (1-31), using arteries from mice in the early or chronic phase of diabetes. In the early stage of diabetes, the ET-1 (1-31)-induced contraction was similar between age- and sex-matched control and streptozotocin (STZ)-induced diabetic mice. In the chronic stage of diabetes, the ET-1 (1-31)-induced contraction was enhanced in diabetic female mice, but not in diabetic male mice (vs. both age-matched control and early-stage diabetic mice). This enhancement was largely prevented by Y27632 (Rho kinase inhibitor), PD98059 [inhibitor of extracellular signal related kinases 1 and 2 (ERK1/2)], or SP600125 [C-jun terminal kinase (JNK) inhibitor]. These data indicate that the ET-1 (1-31)-induced vasoconstriction in the mesenteric artery may be specifically enhanced in established diabetic female mice, and that this enhancement may be due to alterations in the activities of Rho/Rho kinase or mitogen-activated protein kinase.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
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D'Orléans-Juste P, Houde M, Rae G, Bkaily G, Carrier E, Simard E. Endothelin-1 (1–31): From chymase-dependent synthesis to cardiovascular pathologies. Vascul Pharmacol 2008; 49:51-62. [DOI: 10.1016/j.vph.2008.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 06/30/2008] [Indexed: 12/11/2022]
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Su W, Dai DZ, Liu HR, Na T, Dai Y. UPREGULATED ENDOTHELIN SYSTEM IN DIABETIC VASCULAR DYSFUNCTION AND EARLY RETINOPATHY IS REVERSED BY CPU0213 AND TOTAL TRITERPENE ACIDS FROM FRUCTUS CORNI. Clin Exp Pharmacol Physiol 2007; 34:1228-33. [DOI: 10.1111/j.1440-1681.2007.04698.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Watts SW, Thakali K, Smark C, Rondelli C, Fink GD. Big ET-1 processing into vasoactive peptides in arteries and veins. Vascul Pharmacol 2007; 47:302-12. [PMID: 17904426 PMCID: PMC2719821 DOI: 10.1016/j.vph.2007.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 08/28/2007] [Accepted: 08/29/2007] [Indexed: 10/22/2022]
Abstract
The endothelin (ET) peptides are more potent in contracting veins than arteries. The precursor big ET-1 is metabolized by endothelin converting enzyme [ECE; to ET-1 (1-21)], matrix metalloproteases [MMPs; to ET-1 (1-32)] and chymase [to ET-1(1-31)]. We hypothesized that arteries and veins were differently dependent in conversion of big ET-1 to vasoconstrictors. Immunohistochemical, western, zymographic and isometric contractile assays in rat aorta and vena cava were used. Big ET-1 contracted aorta [60+/-17% phenylephrine contraction] but was more efficacious in vena cava [478+/-61% norepinephrine contraction]. ECE and its product ET-1(1-21) were detected in aorta and vena cava, and the ECE inhibitors phosphoramidon and CGS-26393 reduced big ET-1-induced contraction. ET-1 (1-32) contracted aorta and vena cava but inhibition of MMPs with minocycline or GM6001 did not reduce big ET-1-induced contraction; zymography confirmed active tissue MMPs. Aorta and vena cava contracted to the product of chymase, ET-1 (1-31). Chymase was detected in aorta and only weakly in vena cava. Inhibition of chymase (chymostatin, 100 muM) reduced arterial (19% control) but not venous constriction to big ET-1. These results suggest at least one potential significant difference - the role of chymase - in in vitro enzymatic processing of big ET-1 in arteries and veins.
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Affiliation(s)
- Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317, USA.
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Zhou Y, Mitra S, Varadharaj S, Parinandi N, Zweier JL, Flavahan NA. Increased expression of cyclooxygenase-2 mediates enhanced contraction to endothelin ETA receptor stimulation in endothelial nitric oxide synthase knockout mice. Circ Res 2006; 98:1439-45. [PMID: 16645140 DOI: 10.1161/01.res.0000224120.52792.10] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The aim of this study was to determine whether prolonged loss of NO activity, in endothelial NO synthase knockout (eNOS(-/-)) mice, influences endothelin (ET) ETA receptor-mediated smooth muscle contraction and, if so, to define the underlying mechanism(s). In isolated endothelium-denuded abdominal aortas, contractions to the selective ETA receptor agonist ET-1(1-31) were significantly increased in aortas from eNOS(-/-) compared with wild-type (WT) mice. In contrast, contractions to the alpha1-adrenergic agonist phenylephrine or the thromboxane (TX) A2 analog U-46619 were similar between eNOS(-/-) and WT mice. Immunofluorescent and Western blot analysis demonstrated that the aortic expression of ETA receptors was decreased in eNOS(-/-) compared with WT mice. Contractions evoked by ET-1(1-31), but not phenylephrine, were reduced by inhibition of cyclooxygenase-2 (COX-2) (indomethacin or celecoxib) or of TXA2/prostaglandin H2 receptors (SQ-29548). After COX inhibition, contractions to ET-1(1-31) were no longer increased and were actually decreased in eNOS(-/-) compared with WT aortas. Western blot analysis revealed that endothelium-denuded abdominal aortas express COX-2, but not COX-1, and that expression of COX-2 was significantly increased in eNOS(-/-) compared with WT mice. Contractions to the COX substrate arachidonic acid were also increased in eNOS(-/-) aortas. Furthermore, ET-1(1-31) but not phenylephrine stimulated production of the TXA2 metabolite TXB2, which was increased in eNOS(-/-) compared with WT aortas. Therefore, COX-2 plays a crucial and selective role in ETA-mediated smooth muscle contraction. Furthermore, COX-2 expression is increased in eNOS(-/-) mice, which overcomes a reduced expression of ETA receptors and enables a selective increase in contraction to ETA receptor stimulation.
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Affiliation(s)
- Yingbi Zhou
- Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
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Tirapelli CR, Fecteau MH, Honore JC, Legros E, Gobeil F, D'orleans-Juste P. Enzymatic pathways involved in the generation of endothelin-1(1-31) from exogenous big endothelin-1 in the rabbit aorta. Br J Pharmacol 2006; 148:527-35. [PMID: 16633356 PMCID: PMC1751794 DOI: 10.1038/sj.bjp.0706735] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We investigated whether blood vessels contribute to the production of ET-1(1-31) from exogenous big endothelin-1 (BigET-1) in the rabbit and assessed which enzymes are involved in this process. Vascular reactivity experiments, using standard muscle bath procedures, showed that BigET-1 induces contraction in endothelium-intact rabbit aortic rings. Preincubation of the rings with phosphoramidon, CGS35066 or thiorphan reduced BigET-1-induced contraction. Conversely, chymostatin did not affect BigET-1-induced contraction. Thiorphan and phosphoramidon, but not CGS35066 or chymostatin, reduced ET-1(1-31)-induced contraction. None of the enzymatic inhibitors affected the contraction afforded by ET-1.BQ123-, but not BQ788-, selective antagonists for ET(A) and ET(B) receptors, respectively, produced concentration-dependent rightward displacements of the ET-1(1-31) and ET-1 concentration-response curves. By the use of enzymatic assays, we found that the aorta, as well as the heart, lung, kidney and liver, possess a chymase-like activity. Enzyme immunoassays detected significant levels of Ir-ET-1(1-31) in bathing medium of aortas after the addition of BigET-1 (30 nM). Neither thiorphan nor chymostatin altered the levels of Ir-ET-1(1-31). Conversely, the levels of Ir-ET-1(1-31) were increased in the presence of phosphoramidon. This marked increase of the 31-amino-acid peptide was abolished when phosphoramidon and chymostatin were added simultaneously. The major new finding of the present work is that the rabbit aorta generates ET-1(1-31) from exogenously administered BigET-1. Additionally, by measuring the production of ET-1(1-31), we showed that a chymase-like enzyme is involved in this process when ECE and NEP are inhibited by phosphoramidon. Our results also suggest that ET-1(1-31) is an alternate intermediate in the production of ET-1 following BigET-1 administration. Finally, we showed that NEP is the predominant enzymatic pathway involved in the cleavage of ET-1(1-31) to a bioactive metabolite that will act on ET(A) receptors to induce contraction in the rabbit aorta.
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Affiliation(s)
- Carlos R Tirapelli
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
| | - Marie-Helene Fecteau
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
| | - Jean-Claude Honore
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
| | - Eurode Legros
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
| | - Fernand Gobeil
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
| | - Pedro D'orleans-Juste
- Department of Pharmacology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 3001 – 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4
- Author for correspondence:
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Zhang TT, Cui B, Dai DZ, Tang XY. Pharmacological efficacy of CPU 86017 on hypoxic pulmonary hypertension in rats: mediated by direct inhibition of calcium channels and antioxidant action, but indirect effects on the ET-1 pathway. J Cardiovasc Pharmacol 2005; 46:727-34. [PMID: 16306794 DOI: 10.1097/01.fjc.0000184470.58047.79] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Endothelin-1 (ET-1) plays a key role in the pathogenesis of pulmonary hypertension. The present study was conducted to examine the effects of a novel compound p-chlorobenzyltetrahydroberberine (CPU 86017) on endothelin-1 system of hypoxia-induced pulmonary hypertension in rats. SD male rats were divided into control, untreated pulmonary hypertension, nifedipine (10 mg/kg p.o.), and CPU 86017 (80, 40, and 20 mg/kg p.o.) groups. The pulmonary hypertension was established by housing the rats in a hypoxic (10 +/- 0.5% oxygen) chamber 8 hours per day for 4 weeks. Hemodynamic and morphologic assessment exhibited a significant increase in the central vein pressure (CVP), right ventricular systolic pressure (RVSP), and pulmonary arteriole remodeling in the pulmonary hypertensive rats, which were improved by CPU 86017 80 and 40 mg/kg administration (P < 0.01). The elevated pulmonary endothelin-1 level and the over-active preproET-1 and iNOS mRNA expression were also decreased significantly (P < 0.01) in CPU 86017 groups. The maladjustment of redox enzyme system in pulmonary hypertension rats was corrected after treatment. We concluded that CPU 86017 improves pulmonary hypertension mainly to suppress the endothelin-1 pathway at the upstream and downstream via calcium antagonism and antioxidative action, then, resulting in a relief in pathogenesis of the disease.
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Affiliation(s)
- Tian-Tai Zhang
- Research Division of Pharmacology, China Pharmaceutical University, Nanjing, China
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Zhang TT, Cui B, Dai DZ, Su W. CPU 86017, p-chlorobenzyltetrahydroberberine chloride, attenuates monocrotaline-induced pulmonary hypertension by suppressing endothelin pathway. Acta Pharmacol Sin 2005; 26:1309-16. [PMID: 16225752 DOI: 10.1111/j.1745-7254.2005.00214.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIM To elucidate the involvement of the endothelin (ET) pathway in the pathogenesis of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and the therapeutic effect of CPU 86017 (p-chlorobenzyltetrahydroberberine chloride) in rats. METHODS Rats were injected with a single dose (60 mg/kg, sc) of MCT and given CPU 86017 (20, 40, and 80 mg/kg-1/d-1, po) or saline for 28 d. The hemodynamics, mRNA expression, and vascular activity were evaluated. RESULTS Right ventricular systolic pressure and central venous pressures were elevated markedly in the PAH model and decreased by CPU 86017. In the PAH group, the endothelin-1 (ET-1) in serum and lungs was dramatically increased by 54% (79.9 pg/mL, P<0.01) and 93% (166.2 pg/mL, P<0.01), and mRNA levels of preproET-1, eNOS, and iNOS also increased dramatically compared with control. Compared with PAH group, CPU 86017 decreased the content of ET-1 to the normal level in lung tissue, but was less effective in serum. The level of NO was significantly increased in CPU 86017 at 80 and 40 mg/kg-1/d-1 groups in tissue, whereas the difference in serum was not significant. A significant reduction in MDA production and an increase in the SOD activity in the serum and lungs was observed in all three CPU 86017 groups. CPU 86017 80 mg/kg-1/d-1 po increased the activity of cNOS by 33% (P<0.01). The up-regulation of eNOS and iNOS mRNA levels induced by MCT was significantly reversed in 3 CPU 86017 groups, and preproET-1 mRNA abundance was also reduced notably in CPU 86017 80 mg/kg-1/d-1 group vs the PAH group. The KCl-induced vasoconstrictions in the calcium-free medium decreased markedly in PAH group but recovered partially after CPU 86017 intervention. The constrictions in the presence of Ca(2+) was not improved by CPU 86017. The phenylephrine-induced vasoconstrictions in the calcium-free medium decreased markedly in PAH group but not recovered after CPU 86017 intervention. The constrictions in the presence of Ca(2+) completely returned to the normal after CPU 86017 intervention. CONCLUSION CPU 86017 suppressed MCT-induced PAH mainly through an indirect suppression of the ET-1 system, which was involved in the pathogenesis of the disease.
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Affiliation(s)
- Tian-tai Zhang
- Research Division of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
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Fecteau MH, Honoré JC, Plante M, Labonté J, Rae GA, D'Orléans-Juste P. Endothelin-1 (1-31) Is an Intermediate in the Production of Endothelin-1 After Big Endothelin-1 Administration In Vivo. Hypertension 2005; 46:87-92. [PMID: 15956117 DOI: 10.1161/01.hyp.0000170460.24604.23] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The precursor of endothelin-1, big endothelin-1, can be hydrolyzed by chymase to generate endothelin-1 (1-31) in vitro. In the present study, we explored the processes involved in the production of endothelin-1 (1-31) as well as its pharmacodynamic characteristics in the rabbit in vivo. Endothelin-1 (1-31) (1 nmol/kg, injected into the left cardiac ventricle) induced a monophasic increase of mean arterial blood pressure similarly to big endothelin-1 (1-38), whereas endothelin-1 induces a biphasic response. Phosphoramidon, a dual neutral endopeptidase and endothelin-converting enzyme inhibitor, blocked both pressor responses to endothelin-1 (1-31) and big endothelin-1 but not those afforded by endothelin-1. Thiorphan, a neutral endopeptidase inhibitor, markedly inhibited the response to endothelin-1 (1-31) but only weakly reduced that of big endothelin-1. In contrast, CGS 35066, an endothelin-converting enzyme inhibitor, was significantly more efficient against the pressor response to big endothelin-1 than to endothelin-1 (1-31). Furthermore, injection of big endothelin-1 concomitantly with phosphoramidon induced an increase in endothelin-1 (1-31) plasma levels. Finally, intracardiac-administered endothelin-1 (1-31) induced an increase of endothelin-1 plasma levels, which are markedly reduced by phosphoramidon and thiorphan but not by CGS 35066. Our results thus demonstrate that endothelin-1 (1-31) is an alternate intermediate in the production of endothelin-1 after big endothelin-1 administration in the rabbit in vivo.
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Affiliation(s)
- Marie-Hélène Fecteau
- Department of Pharmacology, Medical School, Université de Sherbrooke, 3001 12th Ave N, Sherbrooke, Québec, J1H 5N4, Canada
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Mazzocchi G, Neri G, Rucinski M, Rebuffat P, Spinazzi R, Malendowicz LK, Nussdorfer GG. Ghrelin enhances the growth of cultured human adrenal zona glomerulosa cells by exerting MAPK-mediated proliferogenic and antiapoptotic effects. Peptides 2004; 25:1269-77. [PMID: 15350694 DOI: 10.1016/j.peptides.2004.05.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Revised: 05/14/2004] [Accepted: 05/14/2004] [Indexed: 11/29/2022]
Abstract
Ghrelin is an endogenous ligand of the growth hormone secretagogue receptor (GHS-R), two subtypes of which have been identified and named GHS-R1a and GHS-R1b. Evidence has been provided that ghrelin and its receptors are expressed in the adrenal gland, and we have investigated the possible role of the ghrelin system in the functional regulation of the human adrenal cortex. Reverse transcription-polymerase chain reaction detected the expression of both subtypes of GHS-Rs exclusively in the zona glomerulosa (ZG). Ghrelin did not significantly affect either basal or agonist-stimulated aldosterone secretion from cultured ZG cells. In contrast, ghrelin raised proliferative activity and decreased apoptotic deletion rate of ZG cells, the maximal effective concentration being 10(-8) M. The growth effects of 10(-8) M ghrelin on cultured ZG cells were not affected by either the protein kinase (PK)A and PKC antagonists H-89 and calphostin-C or the mitogen-activated PK (MAPK) p38 antagonist SB-293580, but were abolished by both the tyrosine kinase (TK) and MAPK p42/p44 antagonists tyrphostin-23 (10(-5) M) and PD-98059 (10(-4) M), respectively. Ghrelin (10(-8) M) enhanced TK and MAPK p42/p44 activities of ZG cells. Preincubation with 10(-5) M tyrphostin-23 blocked the ghrelin-induced stimulation of both TK and MAPK p42/p44, while preincubation with 10(-4) M PD-98059 only annulled MAPK p42/p44 stimulation. Collectively, our findings allow us to conclude that ghrelin, acting via GHS-Rs exclusively located in the ZG, enhances the growth of human adrenal cortex, through a mechanism involving the activation of the TK-dependent MAPK p42/p44 cascade.
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Affiliation(s)
- Giuseppina Mazzocchi
- Department of Human Anatomy and Physiology, Section of Anatomy, University of Padua, Via Gabelli 65, Padua I-35121, Italy
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Spät A, Hunyady L. Control of aldosterone secretion: a model for convergence in cellular signaling pathways. Physiol Rev 2004; 84:489-539. [PMID: 15044681 DOI: 10.1152/physrev.00030.2003] [Citation(s) in RCA: 344] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Aldosterone secretion by glomerulosa cells is stimulated by angiotensin II (ANG II), extracellular K(+), corticotrophin, and several paracrine factors. Electrophysiological, fluorimetric, and molecular biological techniques have significantly clarified the molecular action of these stimuli. The steroidogenic effect of corticotrophin is mediated by adenylyl cyclase, whereas potassium activates voltage-operated Ca(2+) channels. ANG II, bound to AT(1) receptors, acts through the inositol 1,4,5-trisphosphate (IP(3))-Ca(2+)/calmodulin system. All three types of IP(3) receptors are coexpressed, rendering a complex control of Ca(2+) release possible. Ca(2+) release is followed by both capacitative and voltage-activated Ca(2+) influx. ANG II inhibits the background K(+) channel TASK and Na(+)-K(+)-ATPase, and the ensuing depolarization activates T-type (Ca(v)3.2) Ca(2+) channels. Activation of protein kinase C by diacylglycerol (DAG) inhibits aldosterone production, whereas the arachidonate released from DAG in ANG II-stimulated cells is converted by lipoxygenase to 12-hydroxyeicosatetraenoic acid, which may also induce Ca(2+) signaling. Feedback effects and cross-talk of signal-transducing pathways sensitize glomerulosa cells to low-intensity stimuli, such as physiological elevations of [K(+)] (< or =1 mM), ANG II, and ACTH. Ca(2+) signaling is also modified by cell swelling, as well as receptor desensitization, resensitization, and downregulation. Long-term regulation of glomerulosa cells involves cell growth and proliferation and induction of steroidogenic enzymes. Ca(2+), receptor, and nonreceptor tyrosine kinases and mitogen-activated kinases participate in these processes. Ca(2+)- and cAMP-dependent phosphorylation induce the transfer of the steroid precursor cholesterol from the cytoplasm to the inner mitochondrial membrane. Ca(2+) signaling, transferred into the mitochondria, stimulates the reduction of pyridine nucleotides.
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Affiliation(s)
- András Spät
- Dept. of Physiology, Semmelweis University, Faculty of Medicine, PO Box 259, H-1444 Budapest, Hungary.
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Malendowicz LK, Conconi MT, Parnigotto PP, Nussdorfer GG. Endogenous adrenomedullin system regulates the growth of rat adrenocortical cells cultured in vitro. REGULATORY PEPTIDES 2003; 112:27-31. [PMID: 12667622 DOI: 10.1016/s0167-0115(03)00019-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The expression of adrenomedullin (AM) system (AM and its receptors), as mRNA and protein, has been detected in the mammalian adrenal zona glomerulosa (ZG) cells. Evidence has been also provided that exogenous AM is able to enhance in vivo and in vitro the proliferative activity of ZG cells. However, the possibility that endogenous AM system may act as a physiological ZG growth regulator has not yet been demonstrated. Hence, we investigated whether the prolonged (48-72 h) suppression of AM gene transcription by a specific antisense oligonucleotide or the long-lasting (24-96 h) blockade of AM receptors by the selective antagonist AM(22-52) are able to affect the growth of rat ZG cells cultured in vitro. Freshly dispersed cells were incubated for 3 h with an AM antisense or a scrambled oligonucleotide, then they were cultured for 48 or 72 h, and proAM mRNA expression and AM content was checked by reverse transcription-polymerase chain reaction and radioimmune assay, respectively. Other ZG cells were cultured in the presence of AM and/or AM(22-52). Growth assay showed that AM (10(-8) M) decreased and AM(22-52) (10(-6) M) increased the duplication time of cultured cells. AM (10(-8) M) raised proliferation index and decreased apoptotic index of cultured cells, and AM(22-52) reversed these effects. AM(22-52) (from 10(-7) to 10(-6) M) and pAM gene suppression by the antisense oligonucleotide significantly lowered proliferation index and increased apoptotic index of cultured cells, both these effects being abrogated by AM (10(-8) M). It is concluded that endogenous AM system plays a relevant role in the autocrine-paracrine regulation of cultured rat ZG-cell growth.
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Affiliation(s)
- Ludwik K Malendowicz
- Department of Human Anatomy and Physiology (Section of Anatomy), School of Medicine, University of Padua, Via Gabelli 65, I-35121, Padua, Italy
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Kitamura H, Cui P, Sharmin S, Yano M, Kido H. Binding of a new bioactive 31-amino-acid endothelin-1 to an endothelin ET(B) or ET(B)-like receptor in porcine lungs. Eur J Pharmacol 2003; 465:31-8. [PMID: 12650830 DOI: 10.1016/s0014-2999(03)01454-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Endothelin-1-(1-31) is a new bioactive 31-amino-acid-length peptide generated from big endothelin-1 by chymase or other chymotrypsin-type proteases with various pathophysiologic functions. In this study, we have detected the specific and monophasic binding of [125I]endothelin-1-(1-31) in porcine lung membranes. Competition studies of [125I]endothelin-1-(1-31) binding by unlabeled endothelin-1-(1-31), endothelin-1, endothelin-3, and antagonists and agonists of endothelin ET(A) and ET(B) receptors suggest that the binding protein is an endothelin ET(B) or ET(B)-like receptor rather than an endothelin ET(A) receptor in porcine lungs. Kinetic studies showed that the affinity of endothelin-1-(1-31) to its receptor was approximately one order of magnitude lower than that of endothelin-1, and that the specific binding of endothelin-1-(1-31) was about 19% of endothelin-1 binding. The binding of [125I]endothelin-1-(1-31) was extremely slow, slower even than that of endothelin-1, and nearly irreversible. This unique quasi-irreversibility may explain the slow-onset and long-lasting biologic effects of this peptide in vivo.
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Affiliation(s)
- Hiroko Kitamura
- Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, Kuramoto-cho 3-18-15, Tokushima 770-8503, Japan
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Andreis PG, Malendowicz LK, Trejter M, Neri G, Spinazzi R, Rossi GP, Nussdorfer GG. Ghrelin and growth hormone secretagogue receptor are expressed in the rat adrenal cortex: Evidence that ghrelin stimulates the growth, but not the secretory activity of adrenal cells. FEBS Lett 2003; 536:173-9. [PMID: 12586359 DOI: 10.1016/s0014-5793(03)00051-6] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ghrelin is an endogenous ligand of the growth hormone secretagogue receptor (GHS-R), which has been originally isolated from rat stomach. Evidence has been previously provided that adrenal gland possesses abundant ghrelin-displaceable GHS-Rs, but nothing is known about the possible role of ghrelin in the regulation of adrenocortical function. Reverse transcription-polymerase chain reaction demonstrated the expression of ghrelin and GHS-R in the rat adrenal cortex, and high adrenal concentrations of immunoreactive ghrelin were detected by radioimmune assay (RIA). Autoradiography localized abundant [(125)I]ghrelin binding sites in the adrenal zona glomerulosa (ZG) and outer zona fasciculata (ZF). Ghrelin (from 10(-10) to 10(-8) M) did not affect either basal steroid hormone (pregnenolone, progesterone, 11-deoxycorticosterone, corticosterone, 18-hydroxycorticosterone and aldosterone) secretion from dispersed ZG and zona fasciculata/reticularis (ZF/R) cells (as evaluated by quantitative high pressure liquid chromatography), or basal and agonist-stimulated aldosterone and corticosterone production from cultured ZG and ZF/R cells, respectively (as measured by RIA). Ghrelin (10(-8) and 10(-6) M) raised basal, but not agonist-stimulated, proliferation rate of cultured ZG cells (percent of cells able to incorporate 5-bromo-2'-deoxyuridine), without affecting apoptotic deletion rate (percent of cells able to incorporate biotinylated nucleosides into apoptotic DNA fragments). The tyrosine kinase (TK) inhibitor tyrphostin-23 and the p42/p44 mitogen-activated protein kinase (MAPK) inhibitor PD-98059 abolished the proliferogenic effect of 10(-8) M ghrelin, while the protein kinase A and C inhibitors H-89 and calphostin-C were ineffective. Ghrelin (10(-8) M) stimulated TK and MAPK activity of dispersed ZG cells, and the effect was abolished by preincubation with tyrphostin-23 and PD-98059, respectively. Tyrphostin-23 annulled ghrelin-induced activation of MAPK activity. Taken together, the present findings indicate that (i) ghrelin and GHS-R are both expressed in the rat adrenal cortex, ghrelin binding sites being very abundant in the ZG; (ii) ghrelin does not affect the secretory activity of rat adrenocortical cells, but significantly enhances the proliferation rate of cultured ZG cells, without affecting apoptotic deletion rate; and (iii) the ZG proliferogenic action of ghrelin involves the TK-dependent activation of the p42/p44 MAPK cascade.
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Affiliation(s)
- Paola G Andreis
- Department of Human Anatomy and Physiology, Section of Anatomy, School of Medicine, University of Padua, Via Gabelli 65, I-35121 Padua, Italy
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Rossi GP, Conconi MT, Malendowicz LK, Nussdorfer GG. Role of the endogenous adrenomedullin system in regulating the secretion and growth of rat adrenal cortex. Hypertens Res 2003; 26 Suppl:S85-92. [PMID: 12630816 DOI: 10.1291/hypres.26.s85] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The expression of components of the adrenomedullin (AM) system (AM and its receptors) has been detected in mammalian adrenal zona glomerulosa (ZG) cells, and evidence has been provided that AM is able to inhibit agonist-stimulated aldosterone secretion from and to enhance the proliferative activity of ZG cells. However, there has been no evidence that the endogenous AM system acts as a physiological regulator of ZG function. Hence, we investigated whether the suppression of AM gene transcription by a specific antisense oligodeoxynucleotide (ODN) is able to alter the secretion and growth of rat ZG cells cultured in vitro. ZG cell cultures were examined 0, 2, 4, 6 and 8 days after treatment with scrambled sense (S)-ODN (control cultures) and AM antisense (A)-ODN. Control cultures, as well as freshly dispersed ZG cells and ODN-untreated cultures, expressed AM as mRNA and protein. A-ODN treatment suppressed AM expression within 4 days and the suppression lasted until day 6. Confluent control cultures displayed basal and angiotensin-II (Ang-II), K(+)- and adrenocorticotropic hormone (ACTH)-stimulated aldosterone secretions similar to those of ODN-untreated cultures. A-ODN treatment magnified the aldosterone response to Ang-II and K+ at days 4 and 6 (but not at day 8), without affecting the basal or ACTH-stimulated secretion. As compared to ODN-untreated and control cultures, non-confluent A-ODN-treated ones showed a 40% elongation in the duplication time, a significant decrease in the proliferation index, and a marked rise in apoptotic index from day 4 to day 8. In conclusion, our study validates the use of A-ODN to block the endogenous AM system, showing that suppression of AM-synthesis requires at least 2 days to become appreciable and persists for at least 6 days. Moreover, it provides the first evidence that endogenous AM plays a physiological role in cultured rat ZG cells, by exerting a buffering action on their acute secretory response to Ang-II and K+ and by maintaining normal basal proliferative and apoptotic activities.
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Affiliation(s)
- Gian Paolo Rossi
- Department of Clinical and Experimental Medicine, University of Padua, Padua, Italy
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21
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Belloni AS, Trejter M, Malendowicz LK, Nussdorfer GG. Adrenomedullin stimulates proliferation and inhibits apoptosis of immature rat thymocytes cultured in vitro. Peptides 2003; 24:295-300. [PMID: 12668215 DOI: 10.1016/s0196-9781(03)00038-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Adrenomedullin (AM) is a hypotensive peptide, which derives from the proteolytic cleavage of pro(p)AM, and acts through two subtypes of receptors, named L1-receptor (L1-R) and calcitonin receptor-like receptor (CRLR). CRLR functions as either a calcitonin gene-related peptide (CGRP) receptor or a selective AM receptor depending on which member of a family of receptor-activity-modifying proteins (RAMPs) is expressed: RAMP1 generates CGRP receptors, while RAMP2 and RAMP3 produce AM receptors. Reverse transcription (RT)-polymerase chain reaction (PCR) consistently allowed the detection of pAM and peptidyl-glycine alpha-amidating monooxygenase (the enzyme converting immature AM to the mature peptide) mRNAs in the thymus cortex of immature (10-day-old) rats. Accordingly, radioimmune assay (RIA) measured low but sizeable AM concentrations in this tissue. RT-PCR also demonstrated the presence of the specific mRNAs of L1-R, CRLR and RAMPs. AM (from 10(-9) to 10(-7)M) increased proliferation index and lowered apoptotic index of cultured immature rat thymocytes, and the effects were annulled by the AM receptor antagonist AM(22-52). In conclusion, our study demonstrated that (1) immature rat thymus cortex expresses AM and the AM receptors L1-R and CRLR/RAMP; and (2) AM, acting via AM(22-52)-sensitive receptors, exerts a potent growth promoting effect on immature rat thymus, by enhancing proliferation and lowering apoptotic death of thymocytes. Taken together, these findings could suggest that AM may play a role in the development of immunity.
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Affiliation(s)
- Anna S Belloni
- Department of Human Anatomy and Physiology, Section of Anatomy, University of Padua, Via Gabelli 65, I-35121, Padua, Italy
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22
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Honoré JC, Plante M, Bkaily G, Rae GA, D'Orléans-Juste P. Pressor and pulmonary responses to ET-1(1-31) in guinea-pigs. Br J Pharmacol 2002; 136:819-28. [PMID: 12110606 PMCID: PMC1573412 DOI: 10.1038/sj.bjp.0704782] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. Endothelin-1(1-31) (ET-1(1-31); 0.25 to 4 nmol kg(-1); i.v.) induced, in the guinea-pig, graded increases in MAP and an indomethacin-sensitive enhancement of pulmonary insufflation pressure (PIP). At all doses, ET-1(1-31) induced a monophasic pressor response, except at 4 nmol kg(-1), which caused a rapid and transient response (first phase: over first 10 min after injection) followed by a more slowly-developing and sustained (second phase: between 10 and 45 min after injection) increase in MAP. ET-1(1-31) was 4 to 10 fold less potent than ET-1 on PIP responses. 2. Phosphoramidon (5 and 10 mg kg(-1)) reduced both pressor and PIP effects of ET-1(1-31). Thiorphan (0.25 and 2.5 mg kg(-1)) did not affect the pressor responses to ET-1(1-31) although its PIP effects were markedly reduced by the NEP inhibitor. A selective endothelin-converting enzyme (ECE) inhibitor, CGS 35066 (1 mg kg(-1)), significantly reduced the second phase pressor response and increase in PIP triggered by ET-1(1-31). 3. The second (but not the first) pressor phase of ET-1(1-31) (4 nmol kg(-1)) was markedly reduced by BQ-123 (selective ET(A) antagonist), whereas the increase of PIP was significantly reduced by BQ-788 (selective ET(B) antagonist). Co-administration of BQ-123 plus BQ-788 abolished ET-1(1-31)-induced increase in PIP, but blockade of the second pressor phase afforded by BQ-123 was now reversed. 4. In guinea-pig isolated perfused lungs, ET-1(1-31) (50 nM) induced the release of prostacyclin and thromboxane A(2), which was inhibited by BQ-788 (5 nM) or thiorphan (25 microM), but not BQ-123 (1 microM). 5. These results suggest that ET-1(1-31) enhances MAP. Its sustained, but not transient, pressor effects are mediated via ET(A) receptor activation. Furthermore, ET-1(1-31) increases airway resistance in vivo and triggers prostacyclin and thromboxane A(2) release from perfused lungs predominantly via ET(B) receptor activation. ET-1(1-31) failed to display any selectivity of action towards either ET(A) or ET(B) receptors in these models. 6. We suggest that, in order to raise MAP, ET-1(1-31) requires conversion to ET-1, predominantly by ECE and to a lesser extent neutral endopeptidase 24.11, whereas the reverse holds true regarding its pharmacological effects in airways.
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Affiliation(s)
- Jean-Claude Honoré
- Department of Pharmacology, Institute of Pharmacology of Sherbrooke; Medical School, Université de Sherbrooke, 3001 12 Avenue North, Sherbrooke (Québec) J1H 5N4, Canada
| | - Mirco Plante
- Department of Pharmacology, Institute of Pharmacology of Sherbrooke; Medical School, Université de Sherbrooke, 3001 12 Avenue North, Sherbrooke (Québec) J1H 5N4, Canada
| | - Ghassan Bkaily
- Department of Anatomy and Cell Biology, Medical School, Université de Sherbrooke, 3001 12 Avenue North, Sherbrooke (Québec) J1H 5N4, Canada
| | - Giles A Rae
- Department of Pharmacology, CCB, Universidade Federal de Santa Catarina, Rua Ferreira Lima, 82, Florianópolis, 88015-420, SC, Brazil
| | - Pedro D'Orléans-Juste
- Department of Pharmacology, Institute of Pharmacology of Sherbrooke; Medical School, Université de Sherbrooke, 3001 12 Avenue North, Sherbrooke (Québec) J1H 5N4, Canada
- Author for correspondence:
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23
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Rossi GP, Seccia TM, Nussdorfer GG. Reciprocal regulation of endothelin-1 and nitric oxide: relevance in the physiology and pathology of the cardiovascular system. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 209:241-72. [PMID: 11580202 DOI: 10.1016/s0074-7696(01)09014-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The endothelium plays a crucial role in the regulation of cardiovascular structure and function by releasing several mediators in response to biochemical and physical stimuli. These mediators are grouped into two classes: (1) endothelium-derived constricting factors (EDCFs) and (2) endothelium-derived relaxing factors (EDRFs), the roles of which are considered to be detrimental and beneficial, respectively. Endothelin-1 (ET-1) and nitric oxide (NO) are the prototypes of EDCFs and EDRFs, respectively, and their effects on the cardiovascular system have been studied in depth. Numerous conditions characterized by an impaired availability of NO have been found to be associated with enhanced synthesis of ET-1, and vice versa, thereby suggesting that these two factors have a reciprocal regulation. Experimental studies have provided evidence that ET-1 may exert a bidirectional effect by either enhancing NO production via ETB receptors located in endothelial cells or blunting it via ETA receptors prevalently located in the vascular smooth muscle cells. Conversely, NO was found to inhibit ET-1 synthesis in different cell types. In vitro and in vivo studies have started to unravel the molecular mechanisms involved in this complex interaction. It has been clarified that several factors affect in opposite directions the transcription of preproET-1 and NO-synthase genes, nuclear factor-KB and peroxisome proliferator-activated receptors playing a key role in these regulatory mechanisms. ET-1 and NO interplay seems to have a great relevance in the physiological regulation of vascular tone and blood pressure, as well as in vascular remodeling. Moreover, an imbalance between ET-1 and NO systems may underly the mechanisms involved in the pathogenesis of systemic and pulmonary hypertension and atherosclerosis.
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Affiliation(s)
- G P Rossi
- Department of Clinical and Experimental Medicine, University Hospital, University of Padua, Italy
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Andreis PG, Neri G, Tortorella C, Aragona F, Rossi GP, Nussdorfer GG. Mechanisms transducing the aldosterone secretagogue signal of endothelins in the human adrenal cortex. Peptides 2002; 23:561-6. [PMID: 11836007 DOI: 10.1016/s0196-9781(01)00631-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Evidence has been provided that the 21-amino acid hypertensive peptide endothelin (ET)-1 exerts a potent secretagogue effect on human adrenocortical zona glomerulosa (ZG), acting through two receptor subtypes, called ET(A) and ET(B), the signaling mechanism(s) of which has (have) not yet been investigated. Collagenase dispersed human ZG cells were obtained from normal adrenals of patients undergoing nephrectomy/adrenalectomy for renal cancer. The selective ET(A)- and ET(B)-receptor activation was obtained by exposing dispersed cells to ET-1 plus the ET(B)-receptor antagonist BQ-788 and to the ET(B)-receptor agonist BQ-3020, respectively. The phospholipase (PL) C inhibitor U-73122 abolished ET(A) receptor-mediated secretory response, but only partially prevented the ET(B) receptor-mediated one. The phosphatidylinositol 3-kinase inhibitor wortmannin, the calmodulin inhibitor W-7 and the protein kinase (PK) C inhibitor calphostin-C significantly blunted the secretory responses ensuing from the activation of both receptor subtypes. When added together, calphostin-C and wortmannin or W-7 abolished ET(A)-mediated secretory response, but only decreased ET(B)-mediated one. The ET(B) receptor-, but not the ET(A) receptor-mediated aldosterone response was partially reversed by the cyclooxygenase (COX) inhibitor indomethacin, which when added together with U-73122 abolished it. ET(A)-receptor activation raised inositol triphosphate (IP(3)) production from dispersed ZG cells, while ET(B)-receptor stimulation enhanced both IP(3) and prostaglandin-E(2) production. Collectively, our findings indicate that ETs stimulate aldosterone secretion from human ZG cells, acting through ET(A) receptors exclusively coupled to PLC/PKC-dependent pathway and ET(B) receptors coupled to both PLC/PKC- and COX-dependent cascades.
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Affiliation(s)
- Paola G Andreis
- Department of Human Anatomy and Physiology, Section of Anatomy, School of Medicine, University of Padua, I-35121, Padua, Italy
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Abstract
Endothelins are a family of peptides, which comprises endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3), each containing 21 amino-acids. ET-1 is a peptide secreted mostly by vascular endothelial cells, the predominant isoform expressed in vasculature and the most potent vasoconstrictor currently known. ET-1 also has inotropic, chemotactic and mitogenic properties. In addition, it influences salt and water homeostasis through its effects on the renin-angiotensin-aldosterone system (RAAS), vasopressin and atrial natriuretic peptide and stimulates the sympathetic nervous system. The overall action of endothelin is to increase blood pressure and vascular tone. Therefore, endothelin antagonists may play an important role in the treatment of cardiac, vascular and renal diseases associated with regional or systemic vasoconstriction and cell proliferation, such as essential hypertension, pulmonary hypertension, chronic heart failure and chronic renal failure. Long-term anti-endothelin therapy may improve symptoms and favourably alter the progression of heart failure. Endothelin appears to participate in induction and progression of sclerotic renal changes, leading to progression to end-stage renal disease. Anti-endothelin therapy might offer additional benefits in the prevention of progression of chronic renal failure in addition to the known benefits of RAAS inhibition. Clinical trials have demonstrated potentially important benefits of endothelin antagonists for patients with essential hypertension, pulmonary hypertension and heart failure. Further studies are necessary to determine the role of anti-endothelin therapy in the treatment of cardiovascular diseases and determine the different roles of selective receptor antagonism vs. mixed ET(A/B)-receptor antagonism in human diseases.
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Affiliation(s)
- Alexei V Agapitov
- Department of Internal Medicine, University of Iowa, Iowa City, 52242, USA
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Rossi GP, Cavallin M, Nussdorfer GG, Pessina AC. The endothelin-aldosterone axis and cardiovascular diseases. J Cardiovasc Pharmacol 2001; 38 Suppl 2:S49-52. [PMID: 11811378 DOI: 10.1097/00005344-200111002-00013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The results of the Randomized Aldactone Evaluation Study (RALES) and of several experimental studies have indicated that excess aldosterone detrimentally affects cardiovascular morbidity and mortality by acting through both classical and non-classical mineralocorticoid receptors. The effects mediated through classical mineralocorticoid receptors entail enhanced sodium and water reabsorption, potassium loss and hypokalaemia, congestion, increased vascular resistance and hypertension. Those occurring through non-classical mineralocorticoid receptors located on myofibroblasts comprise cardiac hypertrophy and fibrosis, which may be due to a direct effect of aldosterone on collagen synthesis. Data obtained in primary aldosteronism patients demonstrated left ventricular hypertrophy, as well as changes in left ventricular filling that can be accounted for by cardiac fibrosis. Available clinical data indicate that in a considerable proportion of congestive heart failure (CHF) patients treated with angiotensin converting enzyme (ACE) inhibitors, aldosterone secretion can escape from blockade of the renin-angiotensin system, thus suggesting that additional mechanisms, besides angiotensin II, can play an important role in the regulation of aldosterone secretion. Compelling evidence indicates that endothelin (ET)-1 is overtly increased in severe CHF and thus is a likely candidate for the aldosterone 'escape' phenomenon in CHF. Endothelin-1 is expressed in the adrenal cortex, together with its receptor subtypes A (ETA) and B (ETB), and directly stimulates aldosterone secretion in different species, in humans by acting via both ETA and ETB receptor subtypes. Moreover, we have recently found that the novel endothelin peptide ET-1 (1-31), by acting as an ETA agonist, can also be involved in the regulation of growth of the adrenal cortex, as well as in the pathogenesis of Conn's adenoma. In this paper, we review the findings suggesting a relationship between activation of the ET-1 system, enhanced aldosterone secretion and cardiac fibrosis and discuss the implications of endothelin antagonism for cardiovascular disease.
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Affiliation(s)
- G P Rossi
- Department of Clinical & Experimental Medicine, University of Padua Medical School, Italy.
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Cramer H, Schmenger K, Heinrich K, Horstmeyer A, Böning H, Breit A, Piiper A, Lundstrom K, Müller-Esterl W, Schroeder C. Coupling of endothelin receptors to the ERK/MAP kinase pathway. Roles of palmitoylation and G(alpha)q. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:5449-59. [PMID: 11606208 DOI: 10.1046/j.0014-2956.2001.02486.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Endothelins are potent mitogens that stimulate extracellular signal-regulated kinases (ERK/MAP kinases) through their cognate G-protein-coupled receptors, ET(A) and ET(B). To address the role of post-translational ET receptor modifications such as acylation on ERK activation and to identify relevant downstream effectors coupling the ET receptor to the ERK signaling cascades we have constructed a panel of palmitoylation-deficient ET receptor mutants with differential G(alpha) protein binding capacity. Endothelin-1 stimulation of wild-type ET(A) or ET(B) induced a fivefold to sixfold increase in ERK in COS-7 and CHO cells whereas full-length nonpalmitoylated ET(A) and ET(B) mutants failed to stimulate ERK. A truncated ET(B) lacking the C-terminal tail domain including putative phosphorylation and arrestin binding site(s) but retaining the critical palmitoylation site(s) was still able to fully stimulate ERK activation. Using mutated ET receptors with selective G-protein-coupling we found that endothelin-induced stimulation of G(alpha)q, but not of G(alpha)i or G(alpha)s, is essential for endothelin-mediated ERK activation. Inhibition of protein kinases A and C or epidermal growth factor receptor kinase failed to prevent ET(A)- and ET(B)-mediated ERK activation whereas blockage of phospholipase C-beta completely abrogated endothelin-promoted ERK activation through ET(A) and ET(B) in recombinant COS-7 and native C6 cells. Complex formation of Ca2+ or inhibition of Src family tyrosine kinases prevented ET-1-induced ERK-2 activation in C6-cells. Our results indicate that endothelin-promoted ERK/MAPK activation criticially depends on palmitoylation but not on phosphorylation of ET receptors, and that the G(alpha)q/phospholipase C-beta/Ca2+/Src signaling cascade is necessary for efficient coupling of ET receptors to the ERK/MAPK pathway.
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Affiliation(s)
- H Cramer
- Institute for Biochemistry II, Johann Wolfgang Goethe University Frankfurt, Theodor-Stern-Kai7, Germany
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