1
|
Tang LL, Yang X, Yu SQ, Qin Q, Xue R, Sun Y, Xiao H, Shang AQ, Liu JQ, Han SQ, Liang C, Lou J, Wang QS, Yu CJ, Wu MM, Zhang ZR. Aldosterone-stimulated endothelial epithelial sodium channel (EnNaC) plays a role in cold exposure–induced hypertension in rats. Front Pharmacol 2022; 13:970812. [PMID: 36278222 PMCID: PMC9582121 DOI: 10.3389/fphar.2022.970812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Previous studies have demonstrated that activated endothelial epithelial sodium channel (EnNaC) impairs vasodilatation, which contributes to salt-sensitive hypertension. Here, we investigate whether mesenteric artery (MA) EnNaC is involved in cold exposure–induced hypertension (CIH) and identify the underlying mechanisms in SD rats.Methods: One group of rats was housed at room temperature and served as control. Three groups of rats were kept in a 4°C cold incubator for 10 h/day; among which two groups were administrated with either benzamil (EnNaC blocker) or eplerenone (mineralocorticoid receptor antagonist, MR). Blood pressure (BP), vasodilatation, and endothelial function were measured with tail-cuff plethysmography, isometric myograph, and Total Nitric Oxide (NO) Assay kit, respectively. A cell-attached patch-clamp technique, in split-open MA, was used to determine the role of EnNaC in CIH rats. Furthermore, the plasma aldosterone levels were detected using an ELISA kit; and Western blot analysis was used to examine the relative expression levels of Sgk1 and Nedd4-2 proteins in the MA of SD rats.Results: We demonstrated that cold exposure increased BP, impaired vasodilatation, and caused endothelial dysfunction in rats. The activity of EnNaC significantly increased, concomitant with an increased level of plasma aldosterone and activation of Sgk1/Nedd4-2 signaling. Importantly, CIH was inhibited by either eplerenone or benzamil. It appeared that cold-induced decrease in NO production and impairment of endothelium-dependent relaxation (EDR) were significantly ameliorated by either eplerenone or benzamil in MA of CIH rats. Moreover, treatment of MAs with aldosterone resulted in an activation of EnNaC, a reduction of NO, and an impairment of EDR, which were significantly inhibited by either eplerenone or GSK650394 (Sgk1 inhibitor) or benzamil.Conclusion: Activation of EnNaC contributes to CIH; we suggest that pharmacological inhibition of the MR/Sgk1/Nedd4-2/EnNaC axis may be a potential therapeutic strategy for CIH.
Collapse
Affiliation(s)
- Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Xu Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Shu-Qi Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Qi Qin
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Rong Xue
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Han Xiao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - An-Qi Shang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Jia-Qun Liu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Song-Qi Han
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Qiu-Shi Wang
- Department of Cardiology, the 1st Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
- Department of Cardiology, the 1st Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
- *Correspondence: Zhi-Ren Zhang,
| |
Collapse
|
2
|
Abstract
Cl- is the major extracellular (Cl-out) and intracellular (Cl-in) anion whose concentration is actively regulated by multiple transporters. These transporters generate Cl- gradients across the plasma membrane and between the cytoplasm and intracellular organelles. [Cl-]in changes rapidly in response to cell stimulation and influences many physiological functions, as well as cellular and systemic homeostasis. However, less appreciated is the signaling function of Cl-. Cl- interacts with multiple proteins to directly modify their activity. This review highlights the signaling function of Cl- and argues that Cl- is a bona fide signaling ion, a function deserving extensive exploration.
Collapse
Affiliation(s)
- Benjamin P Lüscher
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Laura Vachel
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Ehud Ohana
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
3
|
Dagenais A, Tessier MC, Tatur S, Brochiero E, Grygorczyk R, Berthiaume Y. Hypotonic shock modulates Na(+) current via a Cl(-) and Ca(2+)/calmodulin dependent mechanism in alveolar epithelial cells. PLoS One 2013; 8:e74565. [PMID: 24019969 PMCID: PMC3760838 DOI: 10.1371/journal.pone.0074565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 08/05/2013] [Indexed: 12/02/2022] Open
Abstract
Alveolar epithelial cells are involved in Na+ absorption via the epithelial Na+ channel (ENaC), an important process for maintaining an appropriate volume of liquid lining the respiratory epithelium and for lung oedema clearance. Here, we investigated how a 20% hypotonic shock modulates the ionic current in these cells. Polarized alveolar epithelial cells isolated from rat lungs were cultured on permeant filters and their electrophysiological properties recorded. A 20% bilateral hypotonic shock induced an immediate, but transient 52% rise in total transepithelial current and a 67% increase in the amiloride-sensitive current mediated by ENaC. Amiloride pre-treatment decreased the current rise after hypotonic shock, showing that ENaC current is involved in this response. Since Cl- transport is modulated by hypotonic shock, its contribution to the basal and hypotonic-induced transepithelial current was also assessed. Apical NPPB, a broad Cl- channel inhibitor and basolateral DIOA a potassium chloride co-transporter (KCC) inhibitor reduced the total and ENaC currents, showing that transcellular Cl- transport plays a major role in that process. During hypotonic shock, a basolateral Cl- influx, partly inhibited by NPPB is essential for the hypotonic-induced current rise. Hypotonic shock promoted apical ATP secretion and increased intracellular Ca2+. While apyrase, an ATP scavenger, did not inhibit the hypotonic shock current response, W7 a calmodulin antagonist completely prevented the hypotonic current rise. These results indicate that a basolateral Cl- influx as well as Ca2+/calmodulin, but not ATP, are involved in the acute transepithelial current rise elicited by hypotonic shock.
Collapse
Affiliation(s)
- André Dagenais
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- * E-mail:
| | | | - Sabina Tatur
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Emmanuelle Brochiero
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Ryszard Grygorczyk
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
- Centre de Recherche du CHUM (CRCHUM), Centre Hospitalier de l’Université de Montréal, Montreal, Quebec, Canada
| | - Yves Berthiaume
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
| |
Collapse
|
4
|
Nasrallah R, Paris G, Hébert RL. Hypertonicity increases sodium transporters in cortical collecting duct cells independently of PGE2. Biochem Biophys Res Commun 2012; 418:372-7. [PMID: 22266310 DOI: 10.1016/j.bbrc.2012.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 01/06/2012] [Indexed: 12/21/2022]
Abstract
Cyclooxygenase-2 (COX-2) expression is increased by hypertonicity. Therefore we hypothesized that hypertonicity increased PGE(2) can modulate the sodium transporters (Na(+)/K(+)-ATPase: NKA, epithelial sodium channel: ENaC, and sodium hydrogen exchanger: NHE) in M1 cortical collecting duct (CCD) cells. We demonstrated by immunoblotting a 2-fold increase in NKA expression and activity following hypertonic treatment. α-ENaC was also increased, however sgk1, an ENaC activator, decreased in response to hypertonicity. Other CCD sodium transporters (β-ENaC, NHE) were unchanged. Hypertonicity also increased PGE(2) but EP(4) receptor mRNA was unaltered. PGE(2) increased intracellular Na(+) and cAMP production in M1 cells, but PGE(2)-stimulated cAMP response was attenuated by hypertonicity. Overall, PGE(2) had no effect on sodium transporter levels. Since neither COX inhibition nor EP(4) siRNA altered the induction of NKA, we propose that sodium transporter regulation by hypertonicity is independent of PGE(2). Altogether, these data indicate that despite a concomitant increase in PGE(2) production and sodium transporter expression in hypertonicity, both pathways are acting independently of each other.
Collapse
Affiliation(s)
- Rania Nasrallah
- Department of Cellular and Molecular Medicine, Kidney Research Centre, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5
| | | | | |
Collapse
|
6
|
Yamada T, Niisato N, Marunaka Y. Effects of extracellular chloride ion on epithelial sodium channel (ENaC) in arginine vasotocin (AVT)-stimulated renal epithelial cells. ACTA ACUST UNITED AC 2009; 30:193-8. [PMID: 19574722 DOI: 10.2220/biomedres.30.193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The epithelial Na(+) channel (ENaC) contributes to control of blood pressure by reabsorbing Na(+) in the cortical collecting duct of the kidney. The luminal Cl(-) concentration in the duct varies under physiological conditions. As the body Na(+) content is lower, the luminal Cl(-) concentration in the duct becomes lower. Thus, we hypothesized that the extracellular Cl(-) elevates ENaC activity in AVT-stimulated renal epithelial A6 cells (a model cell line of the cortical collecting duct) leading to recovery from a low body Na(+) content. To clarify this point, we studied effects of extracellular Cl(-) concentration on ENaC activity using cell-attached patch clamp technique. We found that ENaC had a single-channel conductance of 4.6 +/- 0.1 pS (mean +/- SE) and channel activity (open probability, Po) of 0.30 +/- 0.02 at a pipette potential of 60 mV. Lowering pipette Cl(-) concentration diminished Po to 0.23 +/- 0.02 associated with a significant decrease in open time from 0.78 +/- 0.03 to 0.61 +/- 0.02 s with no significant change in closed time, and shifted the current-voltage relationship leftward. These results suggest that the extracellular Cl(-) regulates the ENaC-mediated Na(+) reabsorption by affecting ENaC properties in AVT-stimulated renal epithelial cells.
Collapse
Affiliation(s)
- Toshiki Yamada
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | | |
Collapse
|
7
|
An oxygen-sensitive mechanism in regulation of epithelial sodium channel. Proc Natl Acad Sci U S A 2009; 106:2957-62. [PMID: 19196957 DOI: 10.1073/pnas.0809100106] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Epithelial sodium channels (ENaCs) are of immense importance, controlling Na(+) transport across epithelia and thus playing a central role in all aspects of fluid clearance as well as numerous other functions. Regulation of these channels is critical. Here, we show that haem, a regulator of Na(+) transport, directly influences ENaC activity, decreasing channel-open probability (but not unitary conductance) in inside-out patches (but not outside-out). Conversely, exposure to the protein in the presence of NADPH and at normoxic O(2) tension (requirements for activity of hemeoxygenase) increases channel activity. CO, a product of hemeoxygenase activity, activated ENaC in a manner similar to that of haem plus NADPH. However, under hypoxic conditions, inhibition of ENaC by haem occurred even in the presence of NADPH. These data demonstrate a potent, O(2)-sensitive mechanism for regulation of ENaC, in which hemeoxygenase acts as the O(2) sensor, its substrate and product inhibiting and stimulating (respectively) the activity of ENaC.
Collapse
|