1
|
Ramachandran CD, Gholami K, Lam SK, Hoe SZ. Effects of a high-salt diet on MAP and expression levels of renal ENaCs and aquaporins in SHR. Exp Biol Med (Maywood) 2023; 248:1768-1779. [PMID: 37828834 PMCID: PMC10792424 DOI: 10.1177/15353702231198085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 06/05/2023] [Indexed: 10/14/2023] Open
Abstract
An increase in blood pressure by a high-salt (HS) diet may change the expression levels of renal epithelial sodium channels (ENaCs) and aquaporins (AQPs). Spontaneously hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats were exposed to HS and regular-salt (RS) diets for 6 weeks. Mean arterial pressure (MAP) and plasma atrial natriuretic peptide (ANP), angiotensin II (Ang II), aldosterone, and arginine vasopressin (AVP) levels were determined. Expression of mRNA levels of ENaCs and AQPs were quantified by real-time PCR. The MAP was higher in SHRs on the HS diet. Plasma Ang II and aldosterone levels were low while plasma ANP level was high in both strains of rats. Renal expression of mRNA levels of α-, β-, and γ-ENaCs was lowered in SHRs on the HS diet. Meanwhile, renal AQP1, AQP2, and AQP7 mRNA expression levels were lowered in both strains of rats on the HS diet. Suppression of mRNA expression levels of ENaC and AQP subunits suggests that the high-salt-induced increase in the MAP of SHR may not be solely due to renal sodium and water retention.
Collapse
Affiliation(s)
| | - Khadijeh Gholami
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Department of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sau-Kuen Lam
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Department of Pre-Clinical Sciences, Faculty of Medicine & Health Sciences, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - See-Ziau Hoe
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| |
Collapse
|
2
|
Sodium Homeostasis, a Balance Necessary for Life. Nutrients 2023; 15:nu15020395. [PMID: 36678265 PMCID: PMC9862583 DOI: 10.3390/nu15020395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Body sodium (Na) levels must be maintained within a narrow range for the correct functioning of the organism (Na homeostasis). Na disorders include not only elevated levels of this solute (hypernatremia), as in diabetes insipidus, but also reduced levels (hyponatremia), as in cerebral salt wasting syndrome. The balance in body Na levels therefore requires a delicate equilibrium to be maintained between the ingestion and excretion of Na. Salt (NaCl) intake is processed by receptors in the tongue and digestive system, which transmit the information to the nucleus of the solitary tract via a neural pathway (chorda tympani/vagus nerves) and to circumventricular organs, including the subfornical organ and area postrema, via a humoral pathway (blood/cerebrospinal fluid). Circuits are formed that stimulate or inhibit homeostatic Na intake involving participation of the parabrachial nucleus, pre-locus coeruleus, medial tuberomammillary nuclei, median eminence, paraventricular and supraoptic nuclei, and other structures with reward properties such as the bed nucleus of the stria terminalis, central amygdala, and ventral tegmental area. Finally, the kidney uses neural signals (e.g., renal sympathetic nerves) and vascular (e.g., renal perfusion pressure) and humoral (e.g., renin-angiotensin-aldosterone system, cardiac natriuretic peptides, antidiuretic hormone, and oxytocin) factors to promote Na excretion or retention and thereby maintain extracellular fluid volume. All these intake and excretion processes are modulated by chemical messengers, many of which (e.g., aldosterone, angiotensin II, and oxytocin) have effects that are coordinated at peripheral and central level to ensure Na homeostasis.
Collapse
|
3
|
Lugo CI, Liu LP, Bala N, Morales AG, Gholam MF, Abchee JC, Elmoujahid N, Elshikha AS, Avdiaj R, Searcy LA, Denslow ND, Song S, Alli AA. Human Alpha-1 Antitrypsin Attenuates ENaC and MARCKS and Lowers Blood Pressure in Hypertensive Diabetic db/db Mice. Biomolecules 2022; 13:66. [PMID: 36671451 PMCID: PMC9856210 DOI: 10.3390/biom13010066] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/31/2022] Open
Abstract
Hypertension may develop before or after the onset of diabetes and it is known to increase the risk of developing diabetic nephropathy. Alpha-1 antitrypsin (AAT) is a multi-functional protein with beneficial effects in various diseases but its role in reducing blood pressure in the diabetic kidney has not been thoroughly studied. Like blood pressure, epithelial sodium channels (ENaC) and its adaptor protein myristoylated alanine-rich C-kinase substrate (MARCKS) are regulated by circadian rhythms. Our hypothesis is that administration of human AAT (hAAT) reduces blood pressure in hypertensive diabetic mice by attenuating membrane expression of ENaC and its association with the actin cytoskeleton. First, we show hAAT administration results in reduced blood pressure in diabetic db/db mice compared to vehicle treatment in both the inactive and active cycles. Western blotting and immunohistochemistry analyses showed a reduction of ENaC and the actin cytoskeleton protein, MARCKS in the kidneys of diabetic db/db mice treated with hAAT compared to vehicle. hAAT treatment resulted in elevated amounts of extracellular vesicles present in the urine of diabetic db/db mice compared to vehicle treatment both in the inactive and active cycles. Multiple hexosylceramides, among other lipid classes increased in urinary EVs released from hAAT treated hypertensive diabetic mice compared to vehicle treated mice. Taken together, these data suggest hAAT treatment could normalize blood pressure in the diabetic kidney in a mechanism involving attenuation of renal ENaC and MARCKS protein expression and possibly ceramide metabolism to hexosylceramide in kidney cells.
Collapse
Affiliation(s)
- Carlos I. Lugo
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Niharika Bala
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Angelica G. Morales
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mohammed F. Gholam
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah 21423, Saudi Arabia
| | - Julia C. Abchee
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Nasseem Elmoujahid
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Ahmed Samir Elshikha
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Rigena Avdiaj
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Louis A. Searcy
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida College of Veterinary Medicine, Gainesville, FL 32610, USA
| | - Sihong Song
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL 32610, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Medicine Division of Nephrology, Hypertension, and Renal Transplantation, University of Florida College of Medicine, Gainesville, FL 32610, USA
| |
Collapse
|
4
|
Yu L, Nouri MZ, Liu LP, Bala N, Denslow ND, LaDisa JF, Alli AA. C Type Natriuretic Peptide Receptor Activation Inhibits Sodium Channel Activity in Human Aortic Endothelial Cells by Activating the Diacylglycerol-Protein Kinase C Pathway. Int J Mol Sci 2022; 23:13959. [PMID: 36430437 PMCID: PMC9698807 DOI: 10.3390/ijms232213959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
The C-type natriuretic peptide receptor (NPRC) is expressed in many cell types and binds all natriuretic peptides with high affinity. Ligand binding results in the activation or inhibition of various intracellular signaling pathways. Although NPRC ligand binding has been shown to regulate various ion channels, the regulation of endothelial sodium channel (EnNaC) activity by NPRC activation has not been studied. The objective of this study was to investigate mechanisms of EnNaC regulation associated with NPRC activation in human aortic endothelial cells (hAoEC). EnNaC protein expression and activity was attenuated after treating hAoEC with the NPRC agonist cANF compared to vehicle, as demonstrated by Western blotting and patch clamping studies, respectively. NPRC knockdown studies using siRNA's corroborated the specificity of EnNaC regulation by NPRC activation mediated by ligand binding. The concentration of multiple diacylglycerols (DAG) and the activity of protein kinase C (PKC) was augmented after treating hAoEC with cANF compared to vehicle, suggesting EnNaC activity is down-regulated upon NPRC ligand binding in a DAG-PKC dependent manner. The reciprocal cross-talk between NPRC activation and EnNaC inhibition represents a feedback mechanism that presumably is involved in the regulation of endothelial function and aortic stiffness.
Collapse
Affiliation(s)
- Ling Yu
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mohammad-Zaman Nouri
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA
| | - Lauren P. Liu
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Niharika Bala
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32610, USA
| | - John F. LaDisa
- Department of Pediatrics, Section of Cardiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
- Department of Biomedical Engineering, Marquette University and the Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Abdel A. Alli
- Department of Physiology and Aging, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Medicine, Division of Nephrology, Hypertension, and Renal Transplantation, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| |
Collapse
|
5
|
Ertuglu LA, Kirabo A. Dendritic Cell Epithelial Sodium Channel in Inflammation, Salt-Sensitive Hypertension, and Kidney Damage. KIDNEY360 2022; 3:1620-1629. [PMID: 36245645 PMCID: PMC9528365 DOI: 10.34067/kid.0001272022] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/24/2022] [Indexed: 11/27/2022]
Abstract
Salt-sensitive hypertension is a major risk factor for cardiovascular morbidity and mortality. The pathophysiologic mechanisms leading to different individual BP responses to changes in dietary salt remain elusive. Research in the last two decades revealed that the immune system plays a critical role in the development of hypertension and related end organ damage. Moreover, sodium accumulates nonosmotically in human tissue, including the skin and muscle, shifting the dogma on body sodium balance and its regulation. Emerging evidence suggests that high concentrations of extracellular sodium can directly trigger an inflammatory response in antigen-presenting cells (APCs), leading to hypertension and vascular and renal injury. Importantly, sodium entry into APCs is mediated by the epithelial sodium channel (ENaC). Although the role of the ENaC in renal regulation of sodium excretion and BP is well established, these new findings imply that the ENaC may also exert BP modulatory effects in extrarenal tissue through an immune-dependent pathway. In this review, we discuss the recent advances in our understanding of the pathophysiology of salt-sensitive hypertension with a particular focus on the roles of APCs and the extrarenal ENaC.
Collapse
|
6
|
Maaliki D, Itani MM, Itani HA. Pathophysiology and genetics of salt-sensitive hypertension. Front Physiol 2022; 13:1001434. [PMID: 36176775 PMCID: PMC9513236 DOI: 10.3389/fphys.2022.1001434] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Most hypertensive cases are primary and heavily associated with modifiable risk factors like salt intake. Evidence suggests that even small reductions in salt consumption reduce blood pressure in all age groups. In that regard, the ACC/AHA described a distinct set of individuals who exhibit salt-sensitivity, regardless of their hypertensive status. Data has shown that salt-sensitivity is an independent risk factor for cardiovascular events and mortality. However, despite extensive research, the pathogenesis of salt-sensitive hypertension is still unclear and tremendously challenged by its multifactorial etiology, complicated genetic influences, and the unavailability of a diagnostic tool. So far, the important roles of the renin-angiotensin-aldosterone system, sympathetic nervous system, and immune system in the pathogenesis of salt-sensitive hypertension have been studied. In the first part of this review, we focus on how the systems mentioned above are aberrantly regulated in salt-sensitive hypertension. We follow this with an emphasis on genetic variants in those systems that are associated with and/or increase predisposition to salt-sensitivity in humans.
Collapse
Affiliation(s)
- Dina Maaliki
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Maha M. Itani
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Hana A. Itani
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
- *Correspondence: Hana A. Itani,
| |
Collapse
|
7
|
Klemens CA, Dissanayake LV, Levchenko V, Zietara A, Palygin O, Staruschenko A. Modulation of blood pressure regulatory genes in the Agtrap-Plod1 locus associated with a deletion in Clcn6. Physiol Rep 2022; 10:e15417. [PMID: 35927940 PMCID: PMC9353118 DOI: 10.14814/phy2.15417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023] Open
Abstract
The AGTRAP-PLOD1 locus is a conserved gene cluster containing several blood pressure regulatory genes, including CLCN6, MTHFR, NPPA, and NPPB. Previous work revealed that knockout of Clcn6 on the Dahl Salt-Sensitive (SS) rat background (SS-Clcn6) resulted in lower diastolic blood pressure compared to SS-WT rats. Additionally, a recent study found sickle cell anemia patients with mutations in CLCN6 had improved survival and reduced stroke risk. We investigated whether loss of Clcn6 would delay the mortality of Dahl SS rats on an 8% NaCl (HS) diet. No significant difference in survival was found. The ability of Clcn6 to affect mRNA expression of nearby Mthfr, Nppa, and Nppb genes was also tested. On normal salt (0.4% NaCl, NS) diets, renal Mthfr mRNA and protein expression were significantly increased in the SS-Clcn6 rats. MTHFR reduces homocysteine to methionine, but no differences in circulating homocysteine levels were detected. Nppa mRNA levels in cardiac tissue from SS-Clcn6 rat in both normotensive and hypertensive conditions were significantly reduced compared to SS-WT. Nppb mRNA expression in SS-Clcn6 rats on a NS diet was also substantially decreased. Heightened Mthfr expression would be predicted to be protective; however, diminished Nppa and Nppb expression could be deleterious and by preventing or blunting vasodilation, natriuresis, and diuresis that ought to normally occur to offset blood pressure increases. The conserved nature of this genetic locus in humans and rats suggests more studies are warranted to understand how mutations in and around these genes may be influencing the expression of their neighbors.
Collapse
Affiliation(s)
- Christine A. Klemens
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Hypertension and Kidney Research CenterUniversity of South FloridaTampaFloridaUSA
| | - Lashodya V. Dissanayake
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Department of PhysiologyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Vladislav Levchenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
| | - Adrian Zietara
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Department of PhysiologyMedical College of WisconsinMilwaukeeWisconsinUSA
| | - Oleg Palygin
- Department of MedicineMedical University of South CarolinaCharlestonSouth CarolinaUSA
| | - Alexander Staruschenko
- Department of Molecular Pharmacology and PhysiologyUniversity of South FloridaTampaFloridaUSA
- Hypertension and Kidney Research CenterUniversity of South FloridaTampaFloridaUSA
- James A. Haley Veterans' HospitalTampaFloridaUSA
| |
Collapse
|
8
|
Sun XS, Wang XL, Bai M, Song C, Eaton DC, Yue Q, Martin KK, Cai H, Garraway S, Wang LH, Ma HP. Atrial Natriuretic Peptide and the Epithelial Sodium Channel Contribute to Spinal Cord Injury-Induced Polyuria in Mice. J Neurotrauma 2022; 39:724-734. [PMID: 35216518 PMCID: PMC9081061 DOI: 10.1089/neu.2021.0305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Polyuria is found in patients with spinal cord injury (SCI). However, the underlying cellular and molecular mechanism is unknown. Here, we show that mice had elevated urine for 7 days after T10 contusion. Using multi-photon confocal microscopy, we performed intra-vital imaging experiments to evaluate water reabsorption in kidney tubules by examining fluorescent intensity in the lumen of the distal tubule from live mice. The data show that SCI significantly reduced the concentrating function of kidney tubules. The reduced water reabsorption appears to be mediated by atrial natriuretic peptide (ANP) because SCI increased the expression levels of both ANP and natriuretic peptide receptor A (NPR-A) in the kidney cortex. Our patch-clamp single-channel recordings from split-open distal tubules show that SCI decreased the activity of the epithelial sodium channel (ENaC). Western blot combined with confocal microscopy data show that the levels of 70 kD γ-ENaC, which is an active isoform because of proteolytic cleavage, were significantly reduced in distal tubule principal cells. An NPR-A inhibitor (A71915) given intravenously eliminated the effects of SCI on ENaC and polyuria. These data together with previous studies suggest that SCI causes polyuria, probably by reducing ENaC activity through elevating ANP and NPR-A. Further investigation of the signal transduction pathways may provide useful information for discovering an efficient drug to treat SCI-induced polyuria.
Collapse
Affiliation(s)
- Xue-Song Sun
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Xiao-Long Wang
- Department of Orthopedic Surgery, Cancer Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Ming Bai
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Chang Song
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Renal Division, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Douglas C. Eaton
- Renal Division, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Qiang Yue
- Renal Division, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Karmarcha K. Martin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Hui Cai
- Renal Division, Emory University School of Medicine, Atlanta, Georgia, USA.,Section of Nephrology, Atlanta VA Medical Center, Decatur, Georgia, USA
| | - Sandra Garraway
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Li-Hua Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Address correspondence to: Li-Hua Wang, MD, Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - He-Ping Ma
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA.,He-Ping Ma, MD, Department of Cell Biology, Emory University School of Medicine, 615 Michael ST, Suite 601, Atlanta, GA 30322, USA
| |
Collapse
|
9
|
Ilatovskaya DV, Levchenko V, Winsor K, Blass GR, Spires DR, Sarsenova E, Polina I, Zietara A, Paterson M, Kriegel AJ, Staruschenko A. Effects of elevation of ANP and its deficiency on cardiorenal function. JCI Insight 2022; 7:148682. [PMID: 35380994 PMCID: PMC9090260 DOI: 10.1172/jci.insight.148682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/30/2022] [Indexed: 11/17/2022] Open
Abstract
Atrial natriuretic peptide (ANP), encoded by Nppa, is a vasodilatory hormone that promotes salt excretion. Genome-wide association studies identified Nppa as a causative factor of blood pressure development, and in humans, ANP levels were suggested as an indicator of salt sensitivity. This study aimed to provide insights into the effects of ANP on cardiorenal function in salt-sensitive hypertension. To address this question, hypertension was induced in SSNPPA-/- (knockout of Nppa in the Dahl Salt-Sensitive (SS) rat background) or SSWT (wild type Dahl SS) rats by a high salt diet challenge (HS, 4% NaCl for 21 days). Chronic infusion of ANP in SSWT rats attenuated the increase in blood pressure and cardiorenal damage. Overall, SSNPPA-/- strain demonstrated higher blood pressure and intensified cardiac fibrosis (with no changes in ejection fraction) compared to SSWT rats. Furthermore, SSNPPA-/- rats exhibited kidney hypertrophy and higher glomerular injury scores, reduced diuresis, and lower sodium and chloride excretion than SSWT when fed a HS diet. Additionally, the activity of epithelial Na+ channel (ENaC) was found to be increased in the collecting ducts of the SSNPPA-/- rats. Taken together, these data show promise for the therapeutic benefits of ANP and ANP-increasing drugs for treating salt-sensitive hypertension.
Collapse
Affiliation(s)
- Daria V Ilatovskaya
- Department of Physiology, Medical College of Georgia, Augusta, United States of America
| | - Vladislav Levchenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Kristen Winsor
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Gregory R Blass
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Denisha R Spires
- Department of Physiology, Medical College of Georgia, Augusta, United States of America
| | - Elizaveta Sarsenova
- Department of Medicine, Medical University of South Carolina, Charleston, United States of America
| | - Iuliia Polina
- Department of Medicine, Medical University of South Carolina, Charleston, United States of America
| | - Adrian Zietara
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Mark Paterson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Alison J Kriegel
- Department of Physiology, Medical College of Wisconsin, Milwaukee, United States of America
| | | |
Collapse
|
10
|
Zhang M, Ali G, Komatsu S, Zhao R, Ji HL. Prkg2 regulates alveolar type 2-mediated re-alveolarization. Stem Cell Res Ther 2022; 13:111. [PMID: 35313961 PMCID: PMC8935727 DOI: 10.1186/s13287-022-02793-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 02/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The cGMP-dependent type 2 protein kinase, encoded by the prkg2 gene, is highly expressed in alveolar type 2 epithelial (AT2) cells. It is unclear whether prkg2 regulates AT2 cell homeostasis and re-alveolarization of injured lungs. This study aimed to investigate the role of prkg2 in the regulation of the fate of AT2 in vitro. METHODS Primary AT2 cells of wild-type (wt) and prkg2-/- mice were co-cultured with fibroblasts as three-dimensional organoids. The colony formation was analyzed between days 4 and 12 post-seeding. EdU assay was used to detect cells with active DNA synthesis. AT1 and AT2 cells in organoids were visualized with anti-podoplanin and anti-surfactant protein C antibodies, respectively. RESULTS Prkg2-/- AT2 cells developed a greater number of organoids than wt controls. However, compared to wt organoids, a lower number of AT2 but a greater number of AT1 cells were visualized. In addition, a lower number of proliferated cells (EdU+) were observed in prkg2-/- organoids compared to wt controls. The numbers of organoids and EdU+ cells were significantly reduced in protein kinase A (PKA) inhibitor H89-treated wt and prkg2-/- cultures. Organoids and EdU+ cells were increased by lipopolysaccharides (LPS) in both wt and prkg2-/- groups. The increase in the proportion of AT1 and AT2 cells in organoids was only seen in wt controls. CONCLUSIONS Prkg2 may regulate the lineage of AT2 cells, which is affected by endotoxins and the interactive PKA signaling pathway.
Collapse
Affiliation(s)
- Mo Zhang
- Department of Cellular and Molecular Biology, University of Texas at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA.,Xinxiang Medical University, Xinxiang, China
| | - Gibran Ali
- Department of Cellular and Molecular Biology, University of Texas at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA
| | - Satoshi Komatsu
- Department of Cellular and Molecular Biology, University of Texas at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA
| | - Runzhen Zhao
- Department of Cellular and Molecular Biology, University of Texas at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas at Tyler, 11937 US Highway 271, Tyler, TX, 75708-3154, USA. .,Texas Lung Injury Institute, University of Texas at Tyler, Tyler, TX, USA.
| |
Collapse
|
11
|
Iron Inhibits the Translation and Activity of the Renal Epithelial Sodium Channel. BIOLOGY 2022; 11:biology11010123. [PMID: 35053120 PMCID: PMC8772986 DOI: 10.3390/biology11010123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/29/2021] [Accepted: 01/05/2022] [Indexed: 11/16/2022]
Abstract
Hypertension is associated with an increased renal expression and activity of the epithelial sodium channel (ENaC) and iron deficiency. Distal tubules absorb iron, causing perturbations that may influence local responses. In this observational study, we investigated the relationship between iron content and ENaC expression and activity using two cell lines and hepcidin knockout mice (a murine model of iron overload). We found that iron did not transcriptionally regulate ENaC in hepcidin knockout mice or in vitro in collecting duct cells. However, the renal tubules of hepcidin knockout mice have a lower expression of ENaC protein. ENaC activity in cultured Xenopus 2F3 cells and mpkCCD cells was inhibited by iron, which could be reversed by iron chelation. Thus, our novel findings implicate iron as a regulator of ENaC protein and its activity.
Collapse
|
12
|
Rao S, Pena C, Shurmur S, Nugent K. Atrial Natriuretic Peptide: Structure, Function, and Physiological Effects: A Narrative Review. Curr Cardiol Rev 2021; 17:e051121191003. [PMID: 33530911 PMCID: PMC8950497 DOI: 10.2174/1573403x17666210202102210] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/08/2020] [Accepted: 12/21/2020] [Indexed: 12/30/2022] Open
Abstract
Atrial natriuretic peptide (ANP) is a cardiac peptide with multiple physiological effects, including natriuresis, blood pressure regulation, and renin-angiotensin-aldosterone system (RAAS) antagonism. Pre-proANP is synthesized in the atria and must be extensively cleaved by the protease corin to produce the mature 28 amino acid ANP. The downstream signaling pathway of ANP acts through the guanylyl cyclase receptor and the second messenger cGMP. Studies on ANP's physiological effects have demonstrated its activity on channels present in the apical membrane in the renal nephron, potentially inhibiting or decreasing sodium reabsorption. Recent research has also identified several clinical conditions, such as dilated cardiomyopathy, renal failure, and aging, associated with increased and decreased ANP levels. ANP levels could serve as a potential biomarker for the diagnosis of acute stages of heart failure, and ANP infusion could have a role in the management of acute or chronic heart failure.
Collapse
Affiliation(s)
- Sanjana Rao
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
| | - Camilo Pena
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
| | - Scott Shurmur
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
| | - Kenneth Nugent
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA,Address correspondence to this author at the Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA; Tel: 18067436847; E-mail:
| |
Collapse
|
13
|
Jorge ARC, Marinho AD, Silveira JADM, Nogueira Junior FA, de Aquino PEA, Alves APNN, Jorge RJB, Ferreira Junior RS, Monteiro HSA. Phosphodiesterase-5 inhibitor sildenafil attenuates kidney injury induced by Bothrops alternatus snake venom. Toxicon 2021; 202:46-52. [PMID: 34516995 DOI: 10.1016/j.toxicon.2021.08.024] [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: 03/17/2021] [Revised: 08/12/2021] [Accepted: 08/30/2021] [Indexed: 10/20/2022]
Abstract
Acute kidney injury pathogenesis in envenoming by snakes is multifactorial and involves immunologic reactions, hemodynamic disturbances, and direct nephrotoxicity. Sildenafil (SFC), a phosphodiesterase 5 inhibitor, has been reported to protect against pathological kidney changes. OBJECTIVE This study aimed to investigate the protective effect of sildenafil against Bothrops alternatus snake venom (BaV)-induced nephrotoxicity. METHODS Kidneys from Wistar rats (n = 6, weighing 260-300 g) were isolated and divided into four groups: (1) perfused with a modified Krebs-Henseleit solution (MKHS) containing 6 g% of bovine serum albumin; (2) administered 3 μg/mL SFC; (3) perfused with 3 μg/mL BaV; and (4) administered SFC + BaV, both at 3 μg/mL. Subsequently, the perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and percentage of electrolyte tubular sodium and chloride transport (%TNa+, %TCl-, respectively) were evaluated. The cyclic guanosine monophosphate (cGMP) levels were analyzed in the perfusate, and the kidneys were removed to perform oxidative stress and histopathological analyses. RESULTS All renal parameters evaluated were reduced with BaV. In the SFC + BaV group, SFC restored PP to normal values and promoted a significant increase in %TNa+ and %TCl-. cGMP levels were increased in the SFC + BaV group. The oxidative stress biomarkers, malondialdehyde (MDA) and glutathione (GSH), were reduced by BaV. In the SFC + BaV group, a decrease in MDA without an increase in GSH was observed. These findings were confirmed by histological analysis, which showed improvement mainly in tubulis. CONCLUSION Our data suggest the involvement of phosphodiesterase-5 and cGMP in BaV-induced nephrotoxicity since its effects were attenuated by the administration of SFC.
Collapse
Affiliation(s)
- Antônio Rafael Coelho Jorge
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Aline Diogo Marinho
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil.
| | - João Alison de Moraes Silveira
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Francisco Assis Nogueira Junior
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Pedro Everson Alexandre de Aquino
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Ana Paula Negreiros Nunes Alves
- Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil; Department of Dental Clinic, School of Pharmacy, Dentistry and Nursing, Federal University of Ceara, Monsenhor Furtado St., 60.430-350, Fortaleza, CE, Brazil
| | - Roberta Jeane Bezerra Jorge
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Rui Seabra Ferreira Junior
- Center for the Study of Venoms and Venomous Animals, Fazenda Experimental Lageado, São Paulo State University, José Barbosa de Barros St. 1780, 18610-307, Botucatu, SP, Brazil
| | - Helena Serra Azul Monteiro
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| |
Collapse
|
14
|
Liu LP, Gholam MF, Elshikha AS, Kawakibi T, Elmoujahid N, Moussa HH, Song S, Alli AA. Transgenic Mice Overexpressing Human Alpha-1 Antitrypsin Exhibit Low Blood Pressure and Altered Epithelial Transport Mechanisms in the Inactive and Active Cycles. Front Physiol 2021; 12:710313. [PMID: 34630137 PMCID: PMC8493122 DOI: 10.3389/fphys.2021.710313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Human alpha-1 antitrypsin (hAAT) is a versatile protease inhibitor, but little is known about its targets in the aldosterone-sensitive distal nephron and its role in electrolyte balance and blood pressure control. We analyzed urinary electrolytes, osmolality, and blood pressure from hAAT transgenic (hAAT-Tg) mice and C57B/6 wild-type control mice maintained on either a normal salt or high salt diet. Urinary sodium, potassium, and chloride concentrations as well as urinary osmolality were lower in hAAT-Tg mice maintained on a high salt diet during both the active and inactive cycles. hAAT-Tg mice showed a lower systolic blood pressure compared to C57B6 mice when maintained on a normal salt diet but this was not observed when they were maintained on a high salt diet. Cathepsin B protein activity was less in hAAT-Tg mice compared to wild-type controls. Protein expression of the alpha subunit of the sodium epithelial channel (ENaC) alpha was also reduced in the hAAT-Tg mice. Natriuretic peptide receptor C (NPRC) protein expression in membrane fractions of the kidney cortex was reduced while circulating levels of atrial natriuretic peptide (ANP) were greater in hAAT-Tg mice compared to wild-type controls. This study characterizes the electrolyte and blood pressure phenotype of hAAT-Tg mice during the inactive and active cycles and investigates the mechanism by which ENaC activation is inhibited in part by a mechanism involving decreased cathepsin B activity and increased ANP levels in the systemic circulation.
Collapse
Affiliation(s)
- Lauren P Liu
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Mohammed F Gholam
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Ahmed Samir Elshikha
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| | - Tamim Kawakibi
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Nasseem Elmoujahid
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Hassan H Moussa
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Sihong Song
- Department of Pharmaceutics, University of Florida College of Medicine, Gainesville, FL, United States
| | - Abdel A Alli
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, United States.,Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, United States
| |
Collapse
|
15
|
Pandey KN. Molecular Signaling Mechanisms and Function of Natriuretic Peptide Receptor-A in the Pathophysiology of Cardiovascular Homeostasis. Front Physiol 2021; 12:693099. [PMID: 34489721 PMCID: PMC8416980 DOI: 10.3389/fphys.2021.693099] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022] Open
Abstract
The discovery of atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP) and their cognate receptors has greatly increased our knowledge of the control of hypertension and cardiovascular homeostasis. ANP and BNP are potent endogenous hypotensive hormones that elicit natriuretic, diuretic, vasorelaxant, antihypertrophic, antiproliferative, and antiinflammatory effects, largely directed toward the reduction of blood pressure (BP) and cardiovascular diseases (CVDs). The principal receptor involved in the regulatory actions of ANP and BNP is guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA), which produces the intracellular second messenger cGMP. Cellular, biochemical, molecular, genetic, and clinical studies have facilitated understanding of the functional roles of natriuretic peptides (NPs), as well as the functions of their receptors, and signaling mechanisms in CVDs. Transgenic and gene-targeting (gene-knockout and gene-duplication) strategies have produced genetically altered novel mouse models and have advanced our knowledge of the importance of NPs and their receptors at physiological and pathophysiological levels in both normal and disease states. The current review describes the past and recent research on the cellular, molecular, genetic mechanisms and functional roles of the ANP-BNP/NPRA system in the physiology and pathophysiology of cardiovascular homeostasis as well as clinical and diagnostic markers of cardiac disorders and heart failure. However, the therapeutic potentials of NPs and their receptors for the diagnosis and treatment of cardiovascular diseases, including hypertension, heart failure, and stroke have just begun to be expanded. More in-depth investigations are needed in this field to extend the therapeutic use of NPs and their receptors to treat and prevent CVDs.
Collapse
Affiliation(s)
- Kailash N. Pandey
- Department of Physiology, School of Medicine, Tulane University Health Sciences Center, New Orleans, LA, United States
| |
Collapse
|
16
|
Choi MR, Fernández BE. Protective Renal Effects of Atrial Natriuretic Peptide: Where Are We Now? Front Physiol 2021; 12:680213. [PMID: 34135773 PMCID: PMC8202499 DOI: 10.3389/fphys.2021.680213] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
Atrial natriuretic peptide belongs to the family of natriuretic peptides, a system with natriuretic, diuretic, and vasodilator effects that opposes to renin-angiotensin system. In addition to its classic actions, atrial natriuretic peptide exerts a nephroprotective effect given its antioxidant and anti-inflammatory properties, turning it as a beneficial agent against acute and chronic kidney diseases. This minireview describes the most relevant aspects of atrial natriuretic peptide in the kidney, including its renal synthesis, physiological actions through specific receptors, the importance of its metabolism, and its potential use in different pathological scenarios.
Collapse
Affiliation(s)
- Marcelo Roberto Choi
- Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), CONICET - Universidad de Buenos Aires, Buenos Aires, Argentina.,Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Cátedra de Anatomía e Histología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto Universitario de Ciencias de la Salud, Fundación H.A. Barceló, Buenos Aires, Argentina
| | | |
Collapse
|
17
|
Polina I, Domondon M, Fox R, Sudarikova AV, Troncoso M, Vasileva VY, Kashyrina Y, Gooz MB, Schibalski RS, DeLeon-Pennell KY, Fitzgibbon WR, Ilatovskaya DV. Differential effects of low-dose sacubitril and/or valsartan on renal disease in salt-sensitive hypertension. Am J Physiol Renal Physiol 2020; 319:F63-F75. [PMID: 32463726 PMCID: PMC7468826 DOI: 10.1152/ajprenal.00125.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/15/2022] Open
Abstract
Diuretics and renin-angiotensin system blockers are often insufficient to control the blood pressure (BP) in salt-sensitive (SS) subjects. Abundant data support the proposal that the level of atrial natriuretic peptide may correlate with the pathogenesis of SS hypertension. We hypothesized here that increasing atrial natriuretic peptide levels with sacubitril, combined with renin-angiotensin system blockage by valsartan, can be beneficial for alleviation of renal damage in a model of SS hypertension, the Dahl SS rat. To induce a BP increase, rats were challenged with a high-salt 4% NaCl diet for 21 days, and chronic administration of vehicle or low-dose sacubitril and/or valsartan (75 μg/day each) was performed. Urine flow, Na+ excretion, and water consumption were increased on the high-salt diet compared with the starting point (0.4% NaCl) in all groups but remained similar among the groups at the end of the protocol. Upon salt challenge, we observed a mild decrease in systolic BP and urinary neutrophil gelatinase-associated lipocalin levels (indicative of alleviated tubular damage) in the valsartan-treated groups. Sacubitril, as well as sacubitril/valsartan, attenuated the glomerular filtration rate decline induced by salt. Alleviation of protein cast formation and lower renal medullary fibrosis were observed in the sacubitril/valsartan- and valsartan-treated groups, but not when sacubitril alone was administered. Interestingly, proteinuria was mildly mitigated only in rats that received sacubitril/valsartan. Further studies of the effects of sacubitril/valsartan in the setting of SS hypertension, perhaps involving a higher dose of the drug, are warranted to determine if it can interfere with the progression of the disease.
Collapse
Affiliation(s)
- Iuliia Polina
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Mark Domondon
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Rebecca Fox
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Anastasia V Sudarikova
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Miguel Troncoso
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Valeriia Y Vasileva
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Yuliia Kashyrina
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Monika Beck Gooz
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Ryan S Schibalski
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Kristine Y DeLeon-Pennell
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, South Carolina
| | - Wayne R Fitzgibbon
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Daria V Ilatovskaya
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| |
Collapse
|
18
|
Membrane-anchored serine proteases as regulators of epithelial function. Biochem Soc Trans 2020; 48:517-528. [PMID: 32196551 PMCID: PMC9869603 DOI: 10.1042/bst20190675] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023]
Abstract
Cleavage of proteins in the extracellular milieu, including hormones, growth factors and their receptors, ion channels, and various cell adhesion and extracellular matrix molecules, plays a key role in the regulation of cell behavior. Among more than 500 proteolytic enzymes encoded by mammalian genomes, membrane-anchored serine proteases (MASPs), which are expressed on the surface of epithelial cells of all major organs, are excellently suited to mediate signal transduction across the epithelia and are increasingly being recognized as important regulators of epithelial development, function, and disease [ 1-3]. In this minireview, we summarize current knowledge of the in vivo roles of MASPs in acquisition and maintenance of some of the defining functions of epithelial tissues, such as barrier formation, ion transport, and sensory perception.
Collapse
|
19
|
Abstract
PURPOSE OF REVIEW Renal ion transport undergoes dramatic changes during the course of gestation. These adaptations are necessary to meet the dynamic requirements of pregnancy and support fetal development. Pregnancy is characterized by a high demand for both sodium and potassium. Recently there has been work in the field profiling the modifications of the renal tubules in pregnancy to meet these demands. The purpose of this review is to summarize these findings. RECENT FINDINGS The work to date suggests an important role for the distal nephron in both the renal sodium and potassium reabsorption during pregnancy. There is strong evidence that renal sodium reabsorption is mediated by the epithelial sodium channel (ENaC). Whereas renal potassium reabsorption is mediated by upregulation of potassium retaining transporters (HKA2) and downregulation of potassium secreting channels (ROMK, BK). SUMMARY Fetal growth restriction and hypertensive disorders of pregnancy including preeclampsia are marked by suboptimal maternal plasma volume expansion, which is determined by renal electrolyte handling. Therefore, understanding the physiologic demand for sodium and potassium in pregnancy and the adaptations required to support these needs is necessary for the effective treatment of diseased states of pregnancy.
Collapse
|
20
|
Guanylyl Cyclase A in Both Renal Proximal Tubular and Vascular Endothelial Cells Protects the Kidney against Acute Injury in Rodent Experimental Endotoxemia Models. Anesthesiology 2019; 129:296-310. [PMID: 29629958 DOI: 10.1097/aln.0000000000002214] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
WHAT WE ALREADY KNOW ABOUT THIS TOPIC WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Natriuretic peptides are used, based on empirical observations, in intensive care units as antioliguric treatments. We hypothesized that natriuretic peptides prevent lipopolysaccharide-induced oliguria by activating guanylyl cyclase A, a receptor for natriuretic peptides, in proximal tubules and endothelial cells. METHODS Normal Sprague-Dawley rats and mice lacking guanylyl cyclase A in either endothelial cells or proximal tubular cells were challenged with lipopolysaccharide and assessed for oliguria and intratubular flow rate by intravital imaging with multiphoton microscopy. RESULTS Recombinant atrial natriuretic peptide efficiently improved urine volume without changing blood pressure after lipopolysaccharide challenge in rats (urine volume at 4 h, lipopolysaccharide: 0.6 ± 0.3 ml · kg · h; lipopolysaccharide + fluid resuscitation: 4.6 ± 2.0 ml · kg · h; lipopolysaccharide + fluid resuscitation + atrial natriuretic peptide: 9.0 ± 4.8 ml · kg · h; mean ± SD; n = 5 per group). Lipopolysaccharide decreased glomerular filtration rate and slowed intraproximal tubular flow rate, as measured by in vivo imaging. Fluid resuscitation restored glomerular filtration rate but not tubular flow rate. Adding atrial natriuretic peptide to fluid resuscitation improved both glomerular filtration rate and tubular flow rate. Mice lacking guanylyl cyclase A in either proximal tubules or endothelium demonstrated less improvement of tubular flow rate when treated with atrial natriuretic peptide, compared with control mice. Deletion of endothelial, but not proximal tubular, guanylyl cyclase A augmented the reduction of glomerular filtration rate by lipopolysaccharide. CONCLUSIONS Both endogenous and exogenous natriuretic peptides prevent lipopolysaccharide-induced oliguria by activating guanylyl cyclase A in proximal tubules and endothelial cells.
Collapse
|
21
|
McHugh DR, Cotton CU, Moss FJ, Vitko M, Valerio DM, Kelley TJ, Hao S, Jafri A, Drumm ML, Boron WF, Stern RC, McBennett K, Hodges CA. Linaclotide improves gastrointestinal transit in cystic fibrosis mice by inhibiting sodium/hydrogen exchanger 3. Am J Physiol Gastrointest Liver Physiol 2018; 315:G868-G878. [PMID: 30118317 PMCID: PMC9925117 DOI: 10.1152/ajpgi.00261.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrointestinal dysfunction in cystic fibrosis (CF) is a prominent source of pain among patients with CF. Linaclotide, a guanylate cyclase C (GCC) receptor agonist, is a US Food and Drug Administration-approved drug prescribed for chronic constipation but has not been widely used in CF, as the cystic fibrosis transmembrane conductance regulator (CFTR) is the main mechanism of action. However, anecdotal clinical evidence suggests that linaclotide may be effective for treating some gastrointestinal symptoms in CF. The goal of this study was to determine the effectiveness and mechanism of linaclotide in treating CF gastrointestinal disorders using CF mouse models. Intestinal transit, chloride secretion, and intestinal lumen fluidity were assessed in wild-type and CF mouse models in response to linaclotide. CFTR and sodium/hydrogen exchanger 3 (NHE3) response to linaclotide was also evaluated. Linaclotide treatment improved intestinal transit in mice carrying either F508del or null Cftr mutations but did not induce detectable Cl- secretion. Linaclotide increased fluid retention and fluidity of CF intestinal contents, suggesting inhibition of fluid absorption. Targeted inhibition of sodium absorption by the NHE3 inhibitor tenapanor produced improvements in gastrointestinal transit similar to those produced by linaclotide treatment, suggesting that inhibition of fluid absorption by linaclotide contributes to improved gastrointestinal transit in CF. Our results demonstrate that linaclotide improves gastrointestinal transit in CF mouse models by increasing luminal fluidity through inhibiting NHE3-mediated sodium absorption. Further studies are necessary to assess whether linaclotide could improve CF intestinal pathologies in patients. GCC signaling and NHE3 inhibition may be therapeutic targets for CF intestinal manifestations. NEW & NOTEWORTHY Linaclotide's primary mechanism of action in alleviating chronic constipation is through cystic fibrosis transmembrane conductance regulator (CFTR), negating its use in patients with cystic fibrosis (CF). For the first time, our findings suggest that in the absence of CFTR, linaclotide can improve fluidity of the intestinal lumen through the inhibition of sodium/hydrogen exchanger 3. These findings suggest that linaclotide could improve CF intestinal pathologies in patients.
Collapse
Affiliation(s)
- Daniel R. McHugh
- 1Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Calvin U. Cotton
- 2Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio,3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Fraser J. Moss
- 2Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Megan Vitko
- 1Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Dana M. Valerio
- 3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Thomas J. Kelley
- 3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio,4Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Shuyu Hao
- 1Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Anjum Jafri
- 3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Mitchell L. Drumm
- 1Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio,3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Walter F. Boron
- 2Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio,5Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio,6Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Robert C. Stern
- 3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio,7Rainbow Babies and Children’s Hospital, Cleveland, Ohio
| | - Kimberly McBennett
- 3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio,7Rainbow Babies and Children’s Hospital, Cleveland, Ohio
| | - Craig A. Hodges
- 1Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio,3Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio
| |
Collapse
|
22
|
Khoury EE, Kinaneh S, Aronson D, Amir O, Ghanim D, Volinsky N, Azzam Z, Abassi Z. Natriuretic peptides system in the pulmonary tissue of rats with heart failure: potential involvement in lung edema and inflammation. Oncotarget 2018; 9:21715-21730. [PMID: 29774097 PMCID: PMC5955134 DOI: 10.18632/oncotarget.24922] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/05/2018] [Indexed: 12/13/2022] Open
Abstract
Congestive heart failure (CHF) often leads to progressive cardiac hypertrophy and salt/water retention as evident by peripheral and lung edema. Although the pathogenesis of CHF remains largely unclarified, it is widely accepted that neurohormonal changes and inflammatory processes are profoundly involved in structural and functional deterioration of vital organs including, heart, kidney and lungs. Corin, a cardiac serine protease, is responsible for converting pro-ANP and pro-BNP to biologically active natriuretic peptides (NPs). Although the involvement of corin in cardiac hypertrophy and heart failure was extensively studied, the alterations in corin and PCSK6, a key enzyme in the conversion of procorin to corin, have not been studied in the pulmonary tissue. Thus, this study aims at examining the status of PCSK6/Corin in the lung of rats with CHF induced by the creation of aorto-caval fistula (ACF) between the abdominal aorta and vena cava in SD rats. Rats with ACF were divided into 2 subgroups based on the pattern of their daily sodium excretion, compensated and decompensated CHF. Placement of ACF led to cardiac hypertrophy, pulmonary congestion, and renal dysfunction, which were more severe in the decompensated subgroup, despite remarkable elevation of circulatory ANP and BNP levels. Corin mRNA and immunoreactive peptide were detected in pulmonary tissue of all experimental groups. However, the expression and abundance of pulmonary corin significantly increased in the decompensated animals, but not in the compensated ones. Noteworthy, the expression of PCSK6 and ANP/BNP in the pulmonary tissue followed a similar pattern as corin. The upregulation of pulmonary Corin/PCSK6 and NPs were accompanied by local activation of cathepsin L and certain cytokines including IL-6. In light of the anti-inflammatory role of NPs, we postulate that the obtained upregulation of pulmonary PCSK6/Corin along NPs in rats with decompensated CHF may represent a counterbalance response to the inflammatory milieu characterizing CHF especially in severe cases.
Collapse
Affiliation(s)
- Emad E Khoury
- Department of Physiology, The Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Safa Kinaneh
- Department of Physiology, The Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Doron Aronson
- Department of Cardiology, Rambam Health Care Campus, Haifa, Israel
| | - Offer Amir
- Department of Cardiology, B Padeh Medical Center, Poriya, Lower Galilee, Israel.,Faculty of Medicine in the Galilee, Bar-Ilan University, Zefat, Israel
| | - Diab Ghanim
- Department of Cardiology, B Padeh Medical Center, Poriya, Lower Galilee, Israel.,Faculty of Medicine in the Galilee, Bar-Ilan University, Zefat, Israel
| | - Natalia Volinsky
- Department of Cardiology, B Padeh Medical Center, Poriya, Lower Galilee, Israel.,Faculty of Medicine in the Galilee, Bar-Ilan University, Zefat, Israel
| | - Zaher Azzam
- Department of Internal Medicine B, Rambam Health Care Campus, Haifa, Israel
| | - Zaid Abassi
- Department of Physiology, The Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Laboratory Medicine, Rambam Health Care Campus, Haifa, Israel
| |
Collapse
|
23
|
Transepithelial Fluid and Salt Re-Absorption Regulated by cGK2 Signals. Int J Mol Sci 2018; 19:ijms19030881. [PMID: 29547542 PMCID: PMC5877742 DOI: 10.3390/ijms19030881] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/12/2018] [Accepted: 03/14/2018] [Indexed: 12/23/2022] Open
Abstract
Transepithelial fluid and salt re-absorption in epithelial tissues play an important role in fluid and salt homeostasis. In absorptive epithelium, fluid and salt flux is controlled by machinery mainly composed of epithelial sodium channels (ENaC), cystic fibrosis transmembrane conductance regulator (CFTR), Na⁺/H⁺ exchanger (NHE), aquaporin, and sodium potassium adenosine triphosphatase (Na⁺/K⁺-ATPase). Dysregulation of fluid and salt transport across epithelium contributes to the pathogenesis of many diseases, such as pulmonary edema and cystic fibrosis. Intracellular and extracellular signals, i.e., hormones and protein kinases, regulate fluid and salt turnover and resolution. Increasing evidence demonstrates that transepithelial fluid transport is regulated by cyclic guanosine monophosphate-dependent protein kinase (cGK) signals. cGK2 was originally identified and cloned from intestinal specimens, the presence of which has also been confirmed in the kidney and the lung. cGK2 regulates fluid and salt through ENaC, CFTR and NHE. Deficient cGK2 regulation of transepithelial ion transport was seen in acute lung injury, and cGK2 could be a novel druggable target to restore edematous disorder in epithelial tissues.
Collapse
|
24
|
Nielsen PM, Grimm D, Wehland M, Simonsen U, Krüger M. The Combination of Valsartan and Sacubitril in the Treatment of Hypertension and Heart Failure - an Update. Basic Clin Pharmacol Toxicol 2017; 122:9-18. [DOI: 10.1111/bcpt.12912] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 09/15/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Peter Munch Nielsen
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
| | - Daniela Grimm
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
| | - Markus Wehland
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
| | - Ulf Simonsen
- Department of Biomedicine, Pharmacology; Aarhus University; Aarhus C Denmark
| | - Marcus Krüger
- Clinic for Plastic, Aesthetic and Hand Surgery; Otto-von-Guericke-University Magdeburg; Magdeburg Germany
| |
Collapse
|
25
|
Wang TD, Tan RS, Lee HY, Ihm SH, Rhee MY, Tomlinson B, Pal P, Yang F, Hirschhorn E, Prescott MF, Hinder M, Langenickel TH. Effects of Sacubitril/Valsartan (LCZ696) on Natriuresis, Diuresis, Blood Pressures, and NT-proBNP in Salt-Sensitive Hypertension. Hypertension 2017; 69:32-41. [DOI: 10.1161/hypertensionaha.116.08484] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 09/26/2016] [Accepted: 10/20/2016] [Indexed: 11/16/2022]
Abstract
Salt-sensitive hypertension (SSH) is characterized by impaired sodium excretion and subnormal vasodilatory response to salt loading. Sacubitril/valsartan (LCZ696) was hypothesized to increase natriuresis and diuresis and result in superior blood pressure control compared with valsartan in Asian patients with SSH. In this randomized, double-blind, crossover study, 72 patients with SSH received sacubitril/valsartan 400 mg and valsartan 320 mg once daily for 4 weeks each. SSH was diagnosed if the mean arterial pressure increased by ≥10% when patients switched from low (50 mmol/d) to high (320 mmol/d) sodium diet. The primary outcome was cumulative 6- and 24-hour sodium excretion after first dose administration. Compared with valsartan, sacubitril/valsartan was associated with a significant increase in natriuresis (adjusted treatment difference: 24.5 mmol/6 hours, 50.3 mmol/24 hours, both
P
<0.001) and diuresis (adjusted treatment difference: 291.2 mL/6 hours,
P
<0.001; 356.4 mL/24 hours,
P
=0.002) on day 1, but not on day 28, and greater reductions in office and ambulatory blood pressure on day 28. Despite morning dosing of both drugs, ambulatory blood pressure reductions were more pronounced at nighttime than at daytime or the 24-hour average. Compared with valsartan, sacubitril/valsartan significantly reduced N-terminal pro B-type natriuretic peptide levels on day 28 (adjusted treatment difference: −20%;
P
=0.001). Sacubitril/valsartan and valsartan were safe and well tolerated with no significant changes in body weight or serum sodium and potassium levels with either treatments. In conclusion, sacubitril/valsartan compared with valsartan was associated with short-term increases in natriuresis and diuresis, superior office and ambulatory blood pressure control, and significantly reduced N-terminal pro B-type natriuretic peptide levels in Asian patients with SSH.
Clinical Trial Registration—
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT01681576.
Collapse
Affiliation(s)
- Tzung-Dau Wang
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Ru-San Tan
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Hae-Young Lee
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Sang-Hyun Ihm
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Moo-Yong Rhee
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Brian Tomlinson
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Parasar Pal
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Fan Yang
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Elizabeth Hirschhorn
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Margaret F. Prescott
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Markus Hinder
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| | - Thomas H. Langenickel
- From the Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan (T.-D.W.); National Heart Centre, Department of Cardiology, Singapore (R.-S.T.); Seoul National University Hospital, Department of Internal Medicine, South Korea (H.-Y.L.); The Catholic University of Korea Bucheon, St Mary’s Hospital, Department of Cardiology, Bucheon-si, Gyeonggi-do, South Korea (S.-H.I.); Dongguk University Ilsan Hospital,
| |
Collapse
|
26
|
Pavlov TS, Staruschenko A. Involvement of ENaC in the development of salt-sensitive hypertension. Am J Physiol Renal Physiol 2016; 313:F135-F140. [PMID: 28003189 DOI: 10.1152/ajprenal.00427.2016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/20/2016] [Accepted: 12/20/2016] [Indexed: 02/07/2023] Open
Abstract
Salt-sensitive hypertension is associated with renal and vascular dysfunctions, which lead to impaired fluid excretion, increased cardiac output, and total peripheral resistance. It is commonly accepted that increased renal sodium handling and plasma volume expansion are necessary factors for the development of salt-induced hypertension. The epithelial sodium channel (ENaC) is a trimeric ion channel expressed in the distal nephron that plays a critical role in the regulation of sodium reabsorption in both normal and pathological conditions. In this mini-review, we summarize recent studies investigating the role of ENaC in the development of salt-sensitive hypertension. On the basis of experimental data obtained from the Dahl salt-sensitive rats, we and others have demonstrated that abnormal ENaC activation in response to a dietary NaCl load contributes to the development of high blood pressure in this model. The role of different humoral factors, such as the components of the renin-angiotensin-aldosterone system, members of the epidermal growth factors family, arginine vasopressin, and oxidative stress mediating the effects of dietary salt on ENaC are discussed in this review to highlight future research directions and to determine potential molecular targets for drug development.
Collapse
Affiliation(s)
- Tengis S Pavlov
- Division of Hypertension and Vascular Research, Henry Ford Hospital, Detroit, Michigan; and
| | | |
Collapse
|
27
|
Abstract
Cyclic GMP (cGMP) is a ubiquitous intracellular second messenger that mediates a wide spectrum of physiologic processes in multiple cell types within the cardiovascular and nervous systems. Synthesis of cGMP occurs either by NO-sensitive guanylyl cyclases in response to nitric oxide or by membrane-bound guanylyl cyclases in response to natriuretic peptides and has been shown to regulate blood pressure homeostasis by influencing vascular tone, sympathetic nervous system, and sodium and water handling in the kidney. Several cGMPs degrading phosphodiesterases (PDEs), including PDE1 and PDE5, play an important role in the regulation of cGMP signaling. Recent findings revealed that increased activity of cGMP-hydrolyzing PDEs contribute to the development of hypertension. In this review, we will summarize recent research findings regarding the cGMP/PDE signaling in the vasculature, the central nervous system, and the kidney which are associated with the development and maintenance of hypertension.
Collapse
Affiliation(s)
- Evanthia Mergia
- Department of Pharmacology and Toxicology, Ruhr-University Bochum, Bochum, Germany
| | - Johannes Stegbauer
- Department of Nephrology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Germany.
| |
Collapse
|
28
|
Ji HL, Nie HG, Chang Y, Lian Q, Liu SL. CPT-cGMP Is A New Ligand of Epithelial Sodium Channels. Int J Biol Sci 2016; 12:359-66. [PMID: 27019621 PMCID: PMC4807156 DOI: 10.7150/ijbs.13764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/11/2015] [Indexed: 12/28/2022] Open
Abstract
Epithelial sodium channels (ENaC) are localized at the apical membrane of the epithelium, and are responsible for salt and fluid reabsorption. Renal ENaC takes up salt, thereby controlling salt content in serum. Loss-of-function ENaC mutations lead to low blood pressure due to salt-wasting, while gain-of-function mutations cause impaired sodium excretion and subsequent hypertension as well as hypokalemia. ENaC activity is regulated by intracellular and extracellular signals, including hormones, neurotransmitters, protein kinases, and small compounds. Cyclic nucleotides are broadly involved in stimulating protein kinase A and protein kinase G signaling pathways, and, surprisingly, also appear to have a role in regulating ENaC. Increasing evidence suggests that the cGMP analog, CPT-cGMP, activates αβγ-ENaC activity reversibly through an extracellular pathway in a dose-dependent manner. Furthermore, the parachlorophenylthio moiety and ribose 2'-hydroxy group of CPT-cGMP are essential for facilitating the opening of ENaC channels by this compound. Serving as an extracellular ligand, CPT-cGMP eliminates sodium self-inhibition, which is a novel mechanism for stimulating salt reabsorption in parallel to the traditional NO/cGMP/PKG signal pathway. In conclusion, ENaC may be a druggable target for CPT-cGMP, leading to treatments for kidney malfunctions in salt reabsorption.
Collapse
Affiliation(s)
- Hong-Long Ji
- 1. Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| | - Hong-Guang Nie
- 2. Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang 110001, China
| | - Yongchang Chang
- 3. Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, 85013, USA
| | - Qizhou Lian
- 4. Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Shan-Lu Liu
- 5. Department of Molecular Microbiology and Immunology, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| |
Collapse
|
29
|
Zhang Y, Sun Y, Ding G, Huang S, Zhang A, Jia Z. Inhibition of Mitochondrial Complex-1 Prevents the Downregulation of NKCC2 and ENaCα in Obstructive Kidney Disease. Sci Rep 2015. [PMID: 26207612 PMCID: PMC4513566 DOI: 10.1038/srep12480] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Ureteral obstruction with subsequent hydronephrosis is a common clinical complication. Downregulation of renal sodium transporters in obstructed kidneys could contribute to impaired urinary concentrating capability and salt waste following the release of a ureteral obstruction. The current study was undertaken to investigate the role of mitochondrial complex-1 inhibition in modulating sodium transporters in obstructive kidney disease. Following unilateral ureteral obstruction (UUO) for 7 days, a global reduction of sodium transporters, including NHE3, α-Na-K-ATPase, NCC, NKCC2, p-NKCC2, ENaCα, and ENaCγ, was observed, as determined via qRT-PCR and/or Western blotting. Interestingly, inhibition of mitochondrial complex-1 by rotenone markedly reversed the downregulation of NKCC2, p-NKCC2, and ENaCα. In contrast, other sodium transporters were not affected by rotenone. To study the potential mechanisms involved in mediating the effects of rotenone on sodium transporters, we examined a number of known sodium modulators, including PGE2, ET1, Ang II, natriuretic peptides (ANP, BNP, and CNP), and nitric oxide synthases (iNOS, nNOS, and eNOS). Importantly, among these modulators, only BNP and iNOS were significantly reduced by rotenone treatment. Collectively, these findings demonstrated a substantial role of mitochondrial dysfunction in mediating the downregulation of NKCC2 and ENaCα in obstructive kidney disease, possibly via iNOS-derived nitric oxide and BNP.
Collapse
Affiliation(s)
- Yue Zhang
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| | - Ying Sun
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| | - Guixia Ding
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| | - Songming Huang
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| | - Aihua Zhang
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| | - Zhanjun Jia
- 1] Department of Nephrology, Nanjing Children's Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China [2] Institute of Pediatrics, Nanjing Medical University, Nanjing, China [3] Nanjing Key Laboratory of Pediatrics, Nanjing Children Hospital, Affiliated with Nanjing Medical University, Nanjing 210008, China
| |
Collapse
|
30
|
Alli AA, Bao HF, Liu BC, Yu L, Aldrugh S, Montgomery DS, Ma HP, Eaton DC. Calmodulin and CaMKII modulate ENaC activity by regulating the association of MARCKS and the cytoskeleton with the apical membrane. Am J Physiol Renal Physiol 2015; 309:F456-63. [PMID: 26136560 DOI: 10.1152/ajprenal.00631.2014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 06/24/2015] [Indexed: 11/22/2022] Open
Abstract
Phosphatidylinositol bisphosphate (PIP2) regulates epithelial sodium channel (ENaC) open probability. In turn, myristoylated alanine-rich C kinase substrate (MARCKS) protein or MARCKS-like protein 1 (MLP-1) at the plasma membrane regulates the delivery of PIP2 to ENaC. MARCKS and MLP-1 are regulated by changes in cytosolic calcium; increasing calcium promotes dissociation of MARCKS from the membrane, but the calcium-regulatory mechanisms are unclear. However, it is known that increased intracellular calcium can activate calmodulin and we show that inhibition of calmodulin with calmidazolium increases ENaC activity presumably by regulating MARCKS and MLP-1. Activated calmodulin can regulate MARCKS and MLP-1 in two ways. Calmodulin can bind to the effector domain of MARCKS or MLP-1, inactivating both proteins by causing their dissociation from the membrane. Mutations in MARCKS that prevent calmodulin association prevent dissociation of MARCKS from the membrane. Calmodulin also activates CaM kinase II (CaMKII). An inhibitor of CaMKII (KN93) increases ENaC activity, MARCKS association with ENaC, and promotes MARCKS movement to a membrane fraction. CaMKII phosphorylates filamin. Filamin is an essential component of the cytoskeleton and promotes association of ENaC, MARCKS, and MLP-1. Disruption of the cytoskeleton with cytochalasin E reduces ENaC activity. CaMKII phosphorylation of filamin disrupts the cytoskeleton and the association of MARCKS, MLP-1, and ENaC, thereby reducing ENaC open probability. Taken together, these findings suggest calmodulin and CaMKII modulate ENaC activity by destabilizing the association between the actin cytoskeleton, ENaC, and MARCKS, or MLP-1 at the apical membrane.
Collapse
Affiliation(s)
- Abdel A Alli
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Hui-Fang Bao
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Bing-Chen Liu
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Ling Yu
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Summer Aldrugh
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Darrice S Montgomery
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - He-Ping Ma
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| | - Douglas C Eaton
- Center for Cell and Molecular Signaling, Department of Physiology, Emory University School of Medicine; Atlanta, Georgia
| |
Collapse
|
31
|
Stahl K, Stahl M, de Jonge HR, Forrest JN. ANP and CNP activate CFTR expressed in Xenopus laevis oocytes by direct activation of PKA. J Recept Signal Transduct Res 2015; 35:493-504. [PMID: 26016495 DOI: 10.3109/10799893.2015.1015738] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
CONTEXT Acting through different receptors, natriuretic peptides (atrial natriuretic peptide [ANP], brain type natriuretic peptide [BNP] and C-type natriuretic peptide [CNP]) increase intracellular cGMP, which then stimulates different pathways that activate fluid secretion. OBJECTIVE We used two-electrode voltage clamping to define the dominant pathway that is employed when natriuretic peptides activate cystic fibrosis transmembrane conductance regulator (CFTR) in the Xenopus oocyte expression system. Natriuretic peptides could activate CFTR by 1) cGMP cross-activation of protein kinase A (PKA), 2) cGMP activation of cGMP-dependent protein kinase II, 3) cGMP inhibition of phosphodiesterase type III (PDE3), or 4) direct activation of CFTR. MATERIALS AND METHODS cRNA-microinjected Xenopus laevis oocytes were perfused with diverse compounds that examined these pathways of natriuretic peptide signaling. RESULTS AND DISCUSSION ANP stimulated the shark CFTR (sCFTR)-mediated chloride conductance and this activation was inhibited by H-89, a specific inhibitor of PKA. After co-expression of the CNP receptor (NPR-B), sCFTR became stimulatable by CNP and was similarly inhibited by H-89, pointing to cross-activation of PKA. 8-pCPT-cGMP, a relatively cGKII-selective cGMP, failed to stimulate sCFTR. Another membrane-permeable and non-hydrolyzable analog of cGMP, 8-Br-cGMP, stimulated CFTR only at millimolar concentrations, consistent with cross-activation of PKA. The PDE inhibitors EHNA, rolipram, cilostamide, and amrinone did not significantly increase chloride conductance, arguing against a significant role for PDE2, PDE3 and PDE4 signaling in the oocyte. Sildenafil, a PDE5 inhibitor, caused a partial activation of sCFTR channels and this effect was again inhibited by H-89. CONCLUSION From these experiments we conclude that in the Xenopus oocyte system, natriuretic peptides, 8-Br-cGMP, and PDE5 inhibitors activate CFTR by cross-activation of PKA.
Collapse
Affiliation(s)
- Klaus Stahl
- a Nephrology Division, Department of Internal Medicine , Yale University School of Medicine , New Haven , CT , USA .,b The Mount Desert Island Biological Laboratory , Salisbury Cove , ME , USA , and
| | - Maximilian Stahl
- a Nephrology Division, Department of Internal Medicine , Yale University School of Medicine , New Haven , CT , USA .,b The Mount Desert Island Biological Laboratory , Salisbury Cove , ME , USA , and
| | - Hugo R de Jonge
- b The Mount Desert Island Biological Laboratory , Salisbury Cove , ME , USA , and.,c Department of Gastroenterology & Hepatology , Erasmus University Medical Center , Rotterdam , The Netherlands
| | - John N Forrest
- a Nephrology Division, Department of Internal Medicine , Yale University School of Medicine , New Haven , CT , USA .,b The Mount Desert Island Biological Laboratory , Salisbury Cove , ME , USA , and
| |
Collapse
|
32
|
Ray EC, Rondon-Berrios H, Boyd CR, Kleyman TR. Sodium retention and volume expansion in nephrotic syndrome: implications for hypertension. Adv Chronic Kidney Dis 2015; 22:179-84. [PMID: 25908466 PMCID: PMC4409655 DOI: 10.1053/j.ackd.2014.11.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/11/2014] [Accepted: 11/20/2014] [Indexed: 01/09/2023]
Abstract
Sodium retention is a major clinical feature of nephrotic syndrome. The mechanisms responsible for sodium retention in this setting have been a subject of debate for years. Excessive sodium retention occurs in some individuals with nephrotic syndrome in the absence of activation of the renin-angiotensin-aldosterone system, suggesting an intrinsic defect in sodium excretion by the kidney. Recent studies have provided new insights regarding mechanisms by which sodium transporters are activated by factors present in nephrotic urine. These mechanisms likely have a role in the development of hypertension in nephrotic syndrome, where hypertension may be difficult to control, and provide new therapeutic options for the management of blood pressure and edema in the setting of nephrotic syndrome.
Collapse
Affiliation(s)
- Evan C Ray
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA
| | - Helbert Rondon-Berrios
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA.
| | - Cary R Boyd
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA
| | - Thomas R Kleyman
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA; and Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA
| |
Collapse
|
33
|
West CA, McDonough AA, Masilamani SME, Verlander JW, Baylis C. Renal NCC is unchanged in the midpregnant rat and decreased in the late pregnant rat despite avid renal Na+ retention. Am J Physiol Renal Physiol 2015; 309:F63-70. [PMID: 25925254 DOI: 10.1152/ajprenal.00147.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 04/22/2015] [Indexed: 11/22/2022] Open
Abstract
Pregnancy is characterized by plasma volume expansion due to Na(+) retention, driven by aldosterone. The aldosterone-responsive epithelial Na(+) channel is activated in the kidney in pregnancy. In the present study, we investigated the aldosterone-responsive Na(+)-Cl(-) cotransporter (NCC) in mid- and late pregnant rats compared with virgin rats. We determined the abundance of total NCC, phosphorylated NCC (pNCC; pT53, pS71 and pS89), phosphorylated STE20/SPS-1-related proline-alanine-rich protein kinase (pSPAK; pS373), and phosphorylated oxidative stress-related kinase (pOSR1; pS325) in the kidney cortex. We also measured mRNA expression of NCC and members of the SPAK/NCC regulatory kinase network, serum and glucocorticoid-regulated kinase (SGK)1, total with no lysine kinase (WNK)1, WNK3, and WNK4. Additionally, we performed immunohistochemistry for NCC kidneys from virgin and pregnant rats. Total NCC, pNCC, and pSPAK/OSR1 abundance were unchanged in midpregnant versus virgin rats. In late pregnant versus virgin rats, total NCC and pNCC were decreased; however, pSPAK/OSR1 was unchanged. We detected no differences in mRNA expression of NCC, SGK1, total WNK1, WNK3, and WNK4. By immunohistochemistry, NCC was mainly localized to the apical region in virgin rats, and density in the apical region was reduced in late pregnancy. Therefore, despite high circulating aldosterone levels in pregnancy, the aldosterone-responsive transporter NCC is not increased in total or activated (phosphorylated) abundance or in apical localization in midpregnant rats, and all are reduced in late pregnancy. This contrasts to the mineralocorticoid-mediated activation of the epithelial Na(+) channel, which we have previously reported. Why and how NCC escapes aldosterone activation in pregnancy is not clear but may relate to regional differences in aldosterone sensitivity the increased K(+) intake or other undefined mechanisms.
Collapse
Affiliation(s)
- Crystal A West
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida;
| | - Alicia A McDonough
- Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, California; and
| | - Shyama M E Masilamani
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Jill W Verlander
- Department of Medicine, University of Florida, Gainesville, Florida
| | - Chris Baylis
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida; Department of Medicine, University of Florida, Gainesville, Florida
| |
Collapse
|
34
|
Control of ENaC-mediated sodium reabsorption in the distal nephron by Bradykinin. VITAMINS AND HORMONES 2015. [PMID: 25817868 DOI: 10.1016/bs.vh.2014.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Kinins, such as Bradykinin (BK), are peptide hormones of the kallikrein-kinin system. Apart from being a vasodilator, BK also increases urinary sodium excretion to reduce systemic blood pressure. It is becoming appreciated that BK modulates function of the epithelial Na(+) channel in the distal part of the renal nephron to affect tubular sodium reabsorption. In this chapter, we outline the molecular details, as well as discuss the physiological relevance of this regulation for the whole organism sodium homeostasis and setting chronic blood pressure.
Collapse
|
35
|
Abstract
The amiloride-sensitive epithelial Na(+) channel (ENaC) is a key player in the regulation of Na(+) homeostasis. Its functional activity is under continuous control by a variety of signaling molecules, including bioactive peptides of endothelin family. Since ENaC dysfunction is causative for disturbances in total body Na(+) levels associated with the abnormal regulation of blood volume, blood pressure, and lung fluid balance, uncovering the molecular mechanisms of inhibitory modulation or inappropriate activation of ENaC is crucial for the successful treatment of a variety of human diseases including hypertension. The precise regulation of ENaC is particularly important for normal Na(+) and fluid homeostasis in organs where endothelins are known to act: the kidneys, lung, and colon. Inhibition of ENaC by endothelin-1 (ET-1) has been established in renal cells, and several molecular mechanisms of inhibition of ENaC by ET-1 are proposed and will be reviewed in this chapter.
Collapse
Affiliation(s)
- Andrey Sorokin
- Division of Nephrology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
| | | |
Collapse
|
36
|
Theilig F, Wu Q. ANP-induced signaling cascade and its implications in renal pathophysiology. Am J Physiol Renal Physiol 2015; 308:F1047-55. [PMID: 25651559 DOI: 10.1152/ajprenal.00164.2014] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 01/22/2015] [Indexed: 01/06/2023] Open
Abstract
The balance between vasoconstrictor/sodium-retaining and vasodilator/natriuretic systems is essential for maintaining body fluid and electrolyte homeostasis. Natriuretic peptides, such as atrial natriuretic peptide (ANP), belong to the vasodilator/natriuretic system. ANP is produced by the conversion of pro-ANP into ANP, which is achieved by a proteolytical cleavage executed by corin. In the kidney, ANP binds to the natriuretic peptide receptor-A (NPR-A) and enhances its guanylyl cyclase activity, thereby increasing intracellular cyclic guanosine monophosphate production to promote natriuretic and renoprotective responses. In the glomerulus, ANP increases glomerular permeability and filtration rate and antagonizes the deleterious effects of the renin-angiotensin-aldosterone system activation. Along the nephron, natriuretic and diuretic actions of ANP are mediated by inhibiting the basolaterally expressed Na(+)-K(+)-ATPase, reducing apical sodium, potassium, and protein organic cation transporter in the proximal tubule, and decreasing Na(+)-K(+)-2Cl(-) cotransporter activity and renal concentration efficiency in the thick ascending limb. In the medullary collecting duct, ANP reduces sodium reabsorption by inhibiting the cyclic nucleotide-gated cation channels, the epithelial sodium channel, and the heteromeric channel transient receptor potential-vanilloid 4 and -polycystin 2 and diminishes vasopressin-induced water reabsorption. Long-term ANP treatment may lead to NPR-A desensitization and ANP resistance, resulting in augmented sodium and water reabsorption. In mice, corin deficiency impairs sodium excretion and causes salt-sensitive hypertension. Characteristics of ANP resistance and corin deficiency are also encountered in patients with edema-associated diseases, highlighting the importance of ANP signaling in salt-water balance and renal pathophysiology.
Collapse
Affiliation(s)
- Franziska Theilig
- Institute of Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland; and
| | - Qingyu Wu
- Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Ohio
| |
Collapse
|
37
|
Pearce D, Soundararajan R, Trimpert C, Kashlan OB, Deen PM, Kohan DE. Collecting duct principal cell transport processes and their regulation. Clin J Am Soc Nephrol 2015; 10:135-46. [PMID: 24875192 PMCID: PMC4284417 DOI: 10.2215/cjn.05760513] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The principal cell of the kidney collecting duct is one of the most highly regulated epithelial cell types in vertebrates. The effects of hormonal, autocrine, and paracrine factors to regulate principal cell transport processes are central to the maintenance of fluid and electrolyte balance in the face of wide variations in food and water intake. In marked contrast with the epithelial cells lining the proximal tubule, the collecting duct is electrically tight, and ion and osmotic gradients can be very high. The central role of principal cells in salt and water transport is reflected by their defining transporters-the epithelial Na(+) channel (ENaC), the renal outer medullary K(+) channel, and the aquaporin 2 (AQP2) water channel. The coordinated regulation of ENaC by aldosterone, and AQP2 by arginine vasopressin (AVP) in principal cells is essential for the control of plasma Na(+) and K(+) concentrations, extracellular fluid volume, and BP. In addition to these essential hormones, additional neuronal, physical, and chemical factors influence Na(+), K(+), and water homeostasis. Notably, a variety of secreted paracrine and autocrine agents such as bradykinin, ATP, endothelin, nitric oxide, and prostaglandin E2 counterbalance and limit the natriferic effects of aldosterone and the water-retaining effects of AVP. Considerable recent progress has improved our understanding of the transporters, receptors, second messengers, and signaling events that mediate principal cell responses to changing environments in health and disease. This review primarily addresses the structure and function of the key transporters and the complex interplay of regulatory factors that modulate principal cell ion and water transport.
Collapse
Affiliation(s)
- David Pearce
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California
| | - Rama Soundararajan
- Department of Translational Molecular Pathology, MD Anderson Cancer Center, Houston, Texas
| | - Christiane Trimpert
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ossama B. Kashlan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Peter M.T. Deen
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Donald E. Kohan
- Division of Nephrology, University of Utah Health Sciences Center, Salt Lake City, Utah
| |
Collapse
|
38
|
Horita S, Nakamura M, Shirai A, Yamazaki O, Satoh N, Suzuki M, Seki G. Regulatory roles of nitric oxide and angiotensin II on renal tubular transport. World J Nephrol 2014; 3:295-301. [PMID: 25374825 PMCID: PMC4220364 DOI: 10.5527/wjn.v3.i4.295] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 09/05/2014] [Accepted: 10/10/2014] [Indexed: 02/06/2023] Open
Abstract
Renal tubules regulate blood pressure and humoral homeostasis. Mediators that play a significant role in regulating the transport of solutes and water include angiotensin II (AngII) and nitric oxide (NO). AngIIcan significantly raise blood pressure via effects on the heart, vasculature, and renal tubules. AngII generally stimulates sodium reabsorption by triggering sodium and fluid retention in almost all segments of renal tubules. Stimulation of renal proximal tubule (PT) transport is thought to be essential for AngII-mediated hypertension. However, AngII has a biphasic effect on in vitro PT transport in mice, rats, and rabbits: stimulation at low concentrations and inhibition at high concentrations. On the other hand, NO is generally thought to inhibit renal tubular transport. In PTs, NO seems to be involved in the inhibitory effect of AngII. A recent study reports a surprising finding: AngII has a monophasic stimulatory effect on human PT transport. Detailed analysis of signalling mechanisms indicates that in contrast to other species, the human NO/guanosine 3’,5’-cyclic monophosphate/extracellular signal-regulated kinase pathway seems to mediate this effect of Ang II on PT transport. In this review we will discuss recent progress in understanding the effects of AngII and NO on renal tubular transport.
Collapse
|
39
|
Role of microtubules in attenuation of PepG-induced vascular endothelial dysfunction by atrial natriuretic peptide. Biochim Biophys Acta Mol Basis Dis 2014; 1852:104-19. [PMID: 25445540 DOI: 10.1016/j.bbadis.2014.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 09/15/2014] [Accepted: 10/22/2014] [Indexed: 12/30/2022]
Abstract
Apart from control of circulating fluid, atrial natriuretic peptide (ANP) exhibits anti-inflammatory effects in the lung. However, molecular mechanisms of ANP anti-inflammatory effects are not well-understood. Peripheral microtubule (MT) dynamics is essential for agonist-induced regulation of vascular endothelial permeability. Here we studied the role of MT-dependent signaling in ANP protective effects against endothelial cell (EC) barrier dysfunction and acute lung injury induced by Staphylococcus aureus-derived peptidoglican-G (PepG). PepG-induced vascular endothelial dysfunction was accompanied by MT destabilization and disruption of MT network. ANP attenuated PepG-induced MT disassembly, NFκB signaling and activity of MT-associated Rho activator GEF-H1 leading to attenuation of EC inflammatory activation reflected by expression of adhesion molecules ICAM1 and VCAM1. ANP-induced EC barrier preservation and MT stabilization were linked to phosphorylation and inactivation of MT-depolymerizing protein stathmin. Expression of stathmin phosphorylation-deficient mutant abolished ANP protective effects against PepG-induced inflammation and EC permeability. In contrast, siRNA-mediated stathmin knockdown prevented PepG-induced peripheral MT disassembly and endothelial barrier dysfunction. ANP protective effects in a murine model of PepG-induced lung injury were associated with increased phosphorylation of stathmin, while exacerbated lung injury in the ANP knockout mice was accompanied by decreased pool of stable MT. Stathmin knockdown in vivo reversed exacerbation of lung injury in the ANP knockout mice. These results show a novel MT-mediated mechanism of endothelial barrier protection by ANP in pulmonary EC and animal model of PepG-induced lung injury via stathmin-dependent control of MT assembly.
Collapse
|
40
|
Direct regulation of ENaC by bradykinin in the distal nephron. Implications for renal sodium handling. Curr Opin Nephrol Hypertens 2014; 23:122-9. [PMID: 24378775 DOI: 10.1097/01.mnh.0000441053.81339.61] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Locally produced peptide hormones kinins, such as bradykinin, are thought to oppose many of the prohypertensive actions of the renin-angiotensin-aldosterone system. In the kidney, bradykinin, via stimulation of B2 receptors (B2R), favors natriuresis mostly due to the inhibition of tubular Na reabsorption. Recent experimental evidence identifies the epithelial Na channel (ENaC) as a key end effector of bradykinin actions in the distal tubular segments. The focus of this review is the physiological relevance and molecular details of the bradykinin signal to ENaC. RECENT FINDINGS The recent epidemiological GenSalt study demonstrated that genetic variants of the gene encoding B2R show significant associations with the salt sensitivity of blood pressure. Bradykinin was shown to have an inhibitory effect on the distal nephron sodium transport via stimulation of B2 receptor-phospholipase C (B2R-PLC) cascade to decrease ENaC open probability. Genetic ablation of bradykinin receptors in mice led to an augmented ENaC function, particularly during elevated sodium intake, likely contributing to the salt-sensitive hypertensive phenotype. Furthermore, augmentation of bradykinin signaling in the distal nephron was demonstrated to be an important component of the natriuretic and antihypertensive effects of angiotensin converting enzyme inhibition. SUMMARY Salt-sensitive inhibition of ENaC activity by bradykinin greatly advances our understanding of the molecular mechanisms that are responsible for shutting down distal tubule sodium reabsorption during volume expanded conditions to avoid salt-sensitive hypertension.
Collapse
|
41
|
Rossier BC. Epithelial sodium channel (ENaC) and the control of blood pressure. Curr Opin Pharmacol 2014; 15:33-46. [DOI: 10.1016/j.coph.2013.11.010] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 11/29/2022]
|
42
|
Marunaka Y. Importance of expression and function of angiotensin II receptor type 1 in pulmonary epithelial cells. Respir Physiol Neurobiol 2014; 196:39-42. [PMID: 24594106 DOI: 10.1016/j.resp.2014.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 02/25/2014] [Accepted: 02/25/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Yoshinori Marunaka
- Departments of Molecular Cell Physiology and Bio-Ionomics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan; Japan Institute for Food Education and Health, St. Agnes' University, Kyoto 602-8013, Japan.
| |
Collapse
|
43
|
Function of cGMP-dependent protein kinase II in volume load-induced diuresis. Pflugers Arch 2014; 466:2009-18. [PMID: 24442122 DOI: 10.1007/s00424-014-1445-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 01/06/2014] [Indexed: 02/07/2023]
Abstract
Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.
Collapse
|
44
|
Marunaka Y. Characteristics and Pharmacological Regulation of Epithelial Na+ Channel (ENaC) and Epithelial Na+ Transport. J Pharmacol Sci 2014. [DOI: 10.1254/jphs.14r01sr] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
45
|
Miller RL, Wang MH, Gray PA, Salkoff LB, Loewy AD. ENaC-expressing neurons in the sensory circumventricular organs become c-Fos activated following systemic sodium changes. Am J Physiol Regul Integr Comp Physiol 2013; 305:R1141-52. [PMID: 24049115 DOI: 10.1152/ajpregu.00242.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The sensory circumventricular organs (CVOs) are specialized collections of neurons and glia that lie in the midline of the third and fourth ventricles of the brain, lack a blood-brain barrier, and function as chemosensors, sampling both the cerebrospinal fluid and plasma. These structures, which include the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and area postrema (AP), are sensitive to changes in sodium concentration but the cellular mechanisms involved remain unknown. Epithelial sodium channel (ENaC)-expressing neurons of the CVOs may be involved in this process. Here we demonstrate with immunohistochemical and in situ hybridization methods that ENaC-expressing neurons are densely concentrated in the sensory CVOs. These neurons become c-Fos activated, a marker for neuronal activity, after various manipulations of peripheral levels of sodium including systemic injections with hypertonic saline, dietary sodium deprivation, and sodium repletion after prolonged sodium deprivation. The increases seen c-Fos activity in the CVOs were correlated with parallel increases in plasma sodium levels. Since ENaCs play a central role in sodium reabsorption in kidney and other epithelia, we present a hypothesis here suggesting that these channels may also serve a related function in the CVOs. ENaCs could be a significant factor in modulating CVO neuronal activity by controlling the magnitude of sodium permeability in neurons. Hence, some of the same circulating hormones controlling ENaC expression in kidney, such as angiotensin II and atrial natriuretic peptide, may coordinate ENaC expression in sensory CVO neurons and could potentially orchestrate sodium appetite, osmoregulation, and vasomotor sympathetic drive.
Collapse
Affiliation(s)
- Rebecca L Miller
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | | | | | | | | |
Collapse
|