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Lu J, Li Z, Yang Y, Wei F. Chronic exercise improves renal AT 1 and ETB receptor functions via modulating GRK4 expression in obese Zucker rats. Clin Exp Hypertens 2024; 46:2323532. [PMID: 38471134 DOI: 10.1080/10641963.2024.2323532] [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: 01/14/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024]
Abstract
BACKGROUND Physical activity has profound benefits on health, especially in patients with cardiovascular and metabolic disease. Exercise training can reduce oxidative stress, improve renal function, and thus lower blood pressure. However, the effect of exercise training on angiotensin II type 1 receptors (AT1R) and endothelin subtype B receptors (ETBR)-mediated diuresis and natriuresis in obese Zucker rats is unclear. METHODS Lean and obese Zucker rats were exercised or placed on a nonmoving treadmill for 8 weeks. Blood pressure was measured by tail-cuff plethysmography, and functions of AT1R and ETBR in the kidney were measured by natriuresis, respectively. RESULTS Our data showed that exercise training improved glucose and lipid metabolism, renal function and sodium excretion in obese Zucker rats, accompanied by decreased oxidative stress and GRK4 expression in obese Zucker rats. Moreover, exercise training reduced the Candesartan-induced an increase in diuresis and natriuresis and increased ETBR agonists (BQ3020)-mediated diuresis and natriuresis in obese Zucker rats, which were associated with decreased renal AT1R expression and ETBR phosphorylation levels. CONCLUSIONS The results demonstrate that exercise training lowers blood pressure via improving renal AT1R and ETBR function through modulating GRK4 expression in Obese Zucker Rats and provides potentially effective targets for obesity-related hypertension.
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Affiliation(s)
- Jingjing Lu
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
- Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Nephrology, The Secondary Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Zhengsheng Li
- Department of Nephrology, The Secondary Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Yinan Yang
- Department of Nephrology, The Secondary Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Fangning Wei
- The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
- Guangzhou University of Chinese Medicine, Guangzhou, China
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Transcriptional gene silencing of dopamine D3 receptor caused by let-7d mimics in immortalized renal proximal tubule cells of rats. Gene 2016; 580:89-95. [PMID: 26802971 DOI: 10.1016/j.gene.2015.12.071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/25/2015] [Accepted: 12/23/2015] [Indexed: 01/11/2023]
Abstract
Transcriptional gene silencing (TGS) induced by synthetic exogenous short interfering RNAs (siRNAs) that are fully complementary to gene promoters has been demonstrated in mammalian cells. However, it remains unclear whether microRNAs (miRNAs), which are endogenous small regulatory RNAs, can also silence gene transcription. We investigated the regulation mechanism of let-7d on dopamine D3 receptor (DRD3) in immortalized renal proximal tubule (RPT) cells of rats, where let-7d has a predicted homologous target site within DRD3 promoter. We found that let-7d mimics repressed DRD3 expression at the transcription level in RPT cells. Let-7d induced DRD3 inhibition via DNA-methyltransferase 1 (DNMT1) and DNA-methyltransferase 3b (DNMT3b) dependent DNA methylation and the inhibition could be abolished by 5'-aza-2'-deoxycytidine (5-aza-dc), a DNA methylation inhibitor. Let-7d induced DRD3 repression was associated with the recruitment of Argonaute 2 (AGO2) protein. Histone 3 lysine 9 dimethylation (H3K9me2) was involved in the let-7d induced DRD3 TGS, indicating the chromatin-level silencing. In conclusion, our results demonstrated that let-7d may induce DRD3 repression in a transcriptional manner by means of DNMTs dependent DNA methylation and histone modification. It is suggested that miRNAs may act as a transcriptional gene regulator via the recognition of the homologous target site within the gene promoter.
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Yang S, Han Y, Zheng S, Kou X, Asico LD, Huang H, Gao Z, Jose PA, Zeng C. Enhanced Natriuresis and Diuresis in Wistar Rats Caused by the Costimulation of Renal Dopamine D3 and Angiotensin II Type 2 Receptors. Am J Hypertens 2015; 28:1267-76. [PMID: 25770092 DOI: 10.1093/ajh/hpv018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/30/2015] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The kidney, via its regulation of sodium excretion, which is modulated by humoral factors, including the dopamine and renin-angiotensin systems, keeps the blood pressure in the normal range. We have reported a negative interaction between dopamine D3 and AT1 receptors (D3R and AT1R) in renal proximal tubule (RPT) cells. Here, we studied the interaction between D3R and AT2R in vitro and in vivo. METHODS AND RESULTS Stimulation of either the D3R or AT2R, by the intrarenal arterial infusion of PD128907, a D3R agonist, or CGP42112A, an AT2R agonist, induced natriuresis and diuresis that were enhanced by the simultaneous infusion of PD128907 and CGP42112A in Wistar rats. The D3/AT2 receptor interaction was confirmed in in vitro, i.e., stimulation of either the D3R or AT2R inhibited Na(+)-K(+)-ATPase activity that was enhanced by the costimulation of these receptors. D3R and AT2R colocalized and coimmunoprecipitated in kidney and RPT cells (RPTCs). Stimulation of one receptor increased the localization of the other receptor at the plasma cell membrane. ERK1/2-MAPK is involved in the signaling pathway of D3R and AT2R interaction because costimulation of D3R and AT2R significantly increased ERK1/2-MAPK expression in RPTCs; inhibition of ERK1/2-MAPK abolished the inhibition of Na(+)-K(+)-ATPase activity that was enhanced by D3R and AT2R costimulation. CONCLUSIONS Our current study indicates that D3R, in combination with AT2R, enhances natriuresis and diuresis, via ERK1/2-MAPK pathway, that may be involved in the regulation of blood pressure.
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Affiliation(s)
- Sufei Yang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Yu Han
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Shuo Zheng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Xun Kou
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Laureano D Asico
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Hefei Huang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Zhao Gao
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China
| | - Pedro A Jose
- Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China; Chongqing Institute of Cardiology, Chongqing, China;
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Choi MR, Kouyoumdzian NM, Rukavina Mikusic NL, Kravetz MC, Rosón MI, Rodríguez Fermepin M, Fernández BE. Renal dopaminergic system: Pathophysiological implications and clinical perspectives. World J Nephrol 2015; 4:196-212. [PMID: 25949933 PMCID: PMC4419129 DOI: 10.5527/wjn.v4.i2.196] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/29/2014] [Accepted: 02/09/2015] [Indexed: 02/06/2023] Open
Abstract
Fluid homeostasis, blood pressure and redox balance in the kidney are regulated by an intricate interaction between local and systemic anti-natriuretic and natriuretic systems. Intrarenal dopamine plays a central role on this interactive network. By activating specific receptors, dopamine promotes sodium excretion and stimulates anti-oxidant and anti-inflammatory pathways. Different pathological scenarios where renal sodium excretion is dysregulated, as in nephrotic syndrome, hypertension and renal inflammation, can be associated with impaired action of renal dopamine including alteration in biosynthesis, dopamine receptor expression and signal transduction. Given its properties on the regulation of renal blood flow and sodium excretion, exogenous dopamine has been postulated as a potential therapeutic strategy to prevent renal failure in critically ill patients. The aim of this review is to update and discuss on the most recent findings about renal dopaminergic system and its role in several diseases involving the kidneys and the potential use of dopamine as a nephroprotective agent.
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Zhang LN, Li JX, Hao L, Sun YJ, Xie YH, Wu SM, Liu L, Chen XL, Gao ZB. Crosstalk between dopamine receptors and the Na⁺/K⁺-ATPase (review). Mol Med Rep 2013; 8:1291-9. [PMID: 24065247 DOI: 10.3892/mmr.2013.1697] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 09/05/2013] [Indexed: 11/06/2022] Open
Abstract
Dopamine (DA) receptors, which belong to the G protein-coupled receptor family, are the target of ~50% of all modern medicinal drugs and constitute a large and diverse class of proteins whose primary function is to transduce extracellular stimuli into intracellular signals. Na+/K+-ATPase (NKA) is ubiquitous and crucial for the maintenance of intracellular ion homeostasis and excitability. Furthermore, it plays a critical role in diverse effects, including clinical cardiotonic and cardioprotective effects, ischemic preconditioning in the brain, natriuresis, lung edema clearance and other processes. NKA regulation is of physiological and pharmacological importance and has species- and tissue-specific variations. The activation of DA receptors regulates NKA expression/activity and trafficking in various tissues and cells, for example in the kidney, lung, intestine, brain, non-pigmented ciliary epithelium and the vascular bed. DA receptor-mediated regulation of NKA mediates a diverse range of cellular responses and includes endocytosis/exocytosis, phosphorylation/dephosphorylation of the α subunit of NKA and multiple signaling pathways, including phosphatidylinositol (PI)-phospholipase C/protein kinase (PK) C, cAMP/PKA, PI3K, adaptor protein 2, tyrosine phosphatase and mitogen-activated protein kinase/extracellular signal-regulated protein kinase. Furthermore, in brain and HEK293T cells, D1 and D2 receptors exist in a complex with NKA. Among D1 and D2 receptors and NKA, regulations are reciprocal, which leads to crosstalk between DA receptors and NKA. In the present study, the current understanding of signaling mechanisms responsible for the crosstalk between DA receptors and NKA, as well as with specific consequent functions, is reviewed.
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Affiliation(s)
- Li-Nan Zhang
- Department of Pharmacy, College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018, P.R. China
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Meyers KEC, Sethna C. Endothelin antagonists in hypertension and kidney disease. Pediatr Nephrol 2013; 28:711-20. [PMID: 23070275 DOI: 10.1007/s00467-012-2316-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 01/11/2023]
Abstract
The endothelin (ET) system seems to play a pivotal role in hypertension and in proteinuric kidney disease, including the micro- and macro-vascular complications of diabetes. Endothelin-1 (ET-1) is a multifunctional peptide that primarily acts as a potent vasoconstrictor with direct effects on systemic vasculature and the kidney. ET-1 and ET receptors are expressed in the vascular smooth muscle cells, endothelial cells, fibroblasts and macrophages in systemic vasculature and arterioles of the kidney, and are associated with collagen accumulation, inflammation, extracellular matrix remodeling, and renal fibrosis. Experimental evidence and recent clinical studies suggest that endothelin receptor blockade, in particular selective ETAR blockade, holds promise in the treatment of hypertension, proteinuria, and diabetes. Concomitant blockade of the ETB receptor is not usually beneficial and may lead to vasoconstriction and salt and water retention. The side-effect profile of ET receptor antagonists and relatively poor antagonist selectivity for ETA receptor are limitations that need to be addressed. This review will discuss what is currently known about the endothelin system, the role of ET-1 in the pathogenesis of hypertension and kidney disease, and summarize literature on the therapeutic potential of endothelin system antagonism.
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Affiliation(s)
- Kevin E C Meyers
- Nephrology Division, Department of Pediatrics, The Children's Hospital of Philadelphia, 34th and Civic Center Boulevard, Philadelphia, PA 19104, USA.
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Mazzuca MQ, Khalil RA. Vascular endothelin receptor type B: structure, function and dysregulation in vascular disease. Biochem Pharmacol 2012; 84:147-62. [PMID: 22484314 DOI: 10.1016/j.bcp.2012.03.020] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 03/22/2012] [Indexed: 12/21/2022]
Abstract
Endothelin-1 (ET-1) is a major regulator of vascular function, acting via both endothelin receptor type A (ET(A)R) and type B (ET(B)R). Although the role of ET(A)R in vascular smooth muscle (VSM) contraction has been studied, little is known about ET(B)R. ET(B)R is a G-protein coupled receptor with a molecular mass of ~50 kDa and 442 amino acids arranged in seven transmembrane domains. Alternative splice variants of ET(B)R and heterodimerization and cross-talk with ET(A)R may affect the receptor function. ET(B)R has been identified in numerous blood vessels with substantial effects in the systemic, renal, pulmonary, coronary and cerebral circulation. ET(B)R in the endothelium mediates the release of relaxing factors such as nitric oxide, prostacyclin and endothelium-derived hyperpolarizing factor, and could also play a role in ET-1 clearance. ET(B)R in VSM mediates increases in [Ca(2+)](i), protein kinase C, mitogen-activated protein kinase and other pathways of VSM contraction and cell growth. ET-1/ET(A)R signaling has been associated with salt-sensitive hypertension (HTN) and pulmonary arterial hypertension (PAH), and ET(A)R antagonists have shown some benefits in these conditions. In search for other pathogenetic factors and more effective approaches, the role of alterations in endothelial ET(B)R and VSM ET(B)R in vascular dysfunction, and the potential benefits of modulators of ET(B)R in treatment of HTN and PAH are being examined. Combined ET(A)R/ET(B)R antagonists could be more efficacious in the management of conditions involving upregulation of ET(A)R and ET(B)R in VSM. Combined ET(A)R antagonist with ET(B)R agonist may need to be evaluated in conditions associated with decreased endothelial ET(B)R expression/activity.
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Affiliation(s)
- Marc Q Mazzuca
- Vascular Surgery Research Laboratory, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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Zhang Y, Jose PA, Zeng C. Regulation of sodium transport in the proximal tubule by endothelin. CONTRIBUTIONS TO NEPHROLOGY 2011; 172:63-75. [PMID: 21893989 DOI: 10.1159/000328684] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human essential hypertension and rodent genetic hypertension are associated with increased sodium transport in the renal proximal tubule and medullary thick ascending limb of Henle. The proximal tubule, which secretes endothelin (ET), expresses the ET(B) receptor. Low (nM) concentrations of ET, via the ET(B) receptor, inhibit sodium and water transport and ATP-driven drug secretion in the proximal tubule. In contrast, very low (pM) and high nM concentrations of ET increase renal proximal sodium transport, but the receptor involved remains to be determined. The natriuretic effect of ET(B) receptor stimulation is impaired in spontaneously hypertensive rats, due in part to a defective interaction with D(3) dopamine and angiotensin II type 1 receptors. Impaired ET(B) receptor function in the renal proximal tubule may be important in the pathogenesis of genetic hypertension.
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