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Khundmiri SJ, Ecelbarger CM, Amponsem J, Ji H, Sandberg K, Lee DL. PPAR-α knockout leads to elevated blood pressure response to angiotensin II infusion associated with an increase in renal α-1 Na +/K + ATPase protein expression and activity. Life Sci 2022; 296:120444. [PMID: 35245523 PMCID: PMC8969884 DOI: 10.1016/j.lfs.2022.120444] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 02/15/2022] [Accepted: 02/26/2022] [Indexed: 01/13/2023]
Abstract
Peroxisome proliferator activated receptor alpha (PPAR-α) deletion has been shown to increase blood pressure (BP). We hypothesized that the BP increase in PPAR-α KO mice was mediated by increased expression and activity of basolateral Na+/K+ ATPase (NKA) pump. To address this hypothesis, we treated wild-type (WT) and PPAR-α knockout (KO) mice with a slow-pressor dose of angiotensin II (400 ng/kg·min) for 12 days by osmotic minipump. Radiotelemetry showed no significant differences in baseline mean arterial pressure (MAP) between WT and PPAR-α KO mice; however, by day 12 of infusion, MAP was significantly higher in PPAR-α KO mice (156 ± 16) compared to WT mice (138 ± 11 mmHg). NKA activity and protein expression (α1 subunit) were significantly higher in PPAR-α KO mice compared to WT mice. There was no significant difference in NKA mRNA levels. Angiotensin II further increased the expression and activity of the NKA in both genotypes along with the water channel, aquaporin 1 (Aqp1). In contrast, angiotensin II decreased the expression (64-97% reduction in band density) of sodium‑hydrogen exchanger-3 (NHE3), NHE regulatory factor-1 (NHERF1, Slc9a3r1), sodium‑potassium-2-chloride cotransporter (NKCC2), and epithelial sodium channel (ENaC) β- and γ- subunits in the renal cortex of both WT and PPAR-α KO mice, with no difference between genotypes. The sodium-chloride cotransporter (NCC) was also decreased by angiotensin II, but significantly more in PPAR-α KO (59% WT versus 77% KO reduction from their respective vehicle-treated mice). Our results suggest that PPAR-α attenuates angiotensin II-mediated increased blood pressure potentially via reducing expression and activity of the NKA.
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Affiliation(s)
- Syed J Khundmiri
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, DC, USA.
| | - Carolyn M Ecelbarger
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University Washington, DC, USA
| | - Joycemary Amponsem
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, DC, USA
| | - Hong Ji
- Department of Medicine, Georgetown University Washington, DC, USA
| | - Kathryn Sandberg
- Department of Medicine, Georgetown University Washington, DC, USA
| | - Dexter L Lee
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, DC, USA.
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Marck PV, Pessoa MT, Xu Y, Kutz LC, Collins DM, Yan Y, King C, Wang X, Duan Q, Cai L, Xie JX, Lingrel JB, Xie Z, Tian J, Pierre SV. Cardiac Oxidative Signaling and Physiological Hypertrophy in the Na/K-ATPase α1 s/sα2 s/s Mouse Model of High Affinity for Cardiotonic Steroids. Int J Mol Sci 2021; 22:ijms22073462. [PMID: 33801629 PMCID: PMC8036649 DOI: 10.3390/ijms22073462] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 11/25/2022] Open
Abstract
The Na/K-ATPase is the specific receptor for cardiotonic steroids (CTS) such as ouabain and digoxin. At pharmacological concentrations used in the treatment of cardiac conditions, CTS inhibit the ion-pumping function of Na/K-ATPase. At much lower concentrations, in the range of those reported for endogenous CTS in the blood, they stimulate hypertrophic growth of cultured cardiac myocytes through initiation of a Na/K-ATPase-mediated and reactive oxygen species (ROS)-dependent signaling. To examine a possible effect of endogenous concentrations of CTS on cardiac structure and function in vivo, we compared mice expressing the naturally resistant Na/K-ATPase α1 and age-matched mice genetically engineered to express a mutated Na/K-ATPase α1 with high affinity for CTS. In this model, total cardiac Na/K-ATPase activity, α1, α2, and β1 protein content remained unchanged, and the cardiac Na/K-ATPase dose–response curve to ouabain shifted to the left as expected. In males aged 3–6 months, increased α1 sensitivity to CTS resulted in a significant increase in cardiac carbonylated protein content, suggesting that ROS production was elevated. A moderate but significant increase of about 15% of the heart-weight-to-tibia-length ratio accompanied by an increase in the myocyte cross-sectional area was detected. Echocardiographic analyses did not reveal any change in cardiac function, and there was no fibrosis or re-expression of the fetal gene program. RNA sequencing analysis indicated that pathways related to energy metabolism were upregulated, while those related to extracellular matrix organization were downregulated. Consistent with a functional role of the latter, an angiotensin-II challenge that triggered fibrosis in the α1r/rα2s/s mouse failed to do so in the α1s/sα2s/s. Taken together, these results are indicative of a link between circulating CTS, Na/K-ATPase α1, ROS, and physiological cardiac hypertrophy in mice under baseline laboratory conditions.
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Affiliation(s)
- Pauline V. Marck
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Marco T. Pessoa
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Yunhui Xu
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Laura C. Kutz
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Dominic M. Collins
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Yanling Yan
- Department of Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25755, USA;
| | - Cierra King
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Xiaoliang Wang
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Qiming Duan
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA;
| | - Liquan Cai
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Jeffrey X. Xie
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Jerry B. Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Jiang Tian
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Sandrine V. Pierre
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
- Correspondence: ; Tel.: +1-(304)-696-3505
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Lopina OD, Tverskoi AM, Klimanova EA, Sidorenko SV, Orlov SN. Ouabain-Induced Cell Death and Survival. Role of α1-Na,K-ATPase-Mediated Signaling and [Na +] i/[K +] i-Dependent Gene Expression. Front Physiol 2020; 11:1060. [PMID: 33013454 PMCID: PMC7498651 DOI: 10.3389/fphys.2020.01060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/31/2020] [Indexed: 12/12/2022] Open
Abstract
Ouabain is of cardiotonic steroids (CTS) family that is plant-derived compounds and is known for many years as therapeutic and cytotoxic agents. They are specific inhibitors of Na,K-ATPase, the enzyme, which pumps Na+ and K+ across plasma membrane of animal cells. Treatment of cells by CTS affects various cellular functions connected with the maintenance of the transmembrane gradient of Na+ and K+. Numerous studies demonstrated that binding of CTS to Na,K-ATPase not only suppresses its activity but also induces some signal pathways. This review is focused on different mechanisms of two ouabain effects: their ability (1) to protect rodent cells from apoptosis through the expression of [Na+]i-sensitive genes and (2) to trigger death of non-rodents cells (so-called «oncosis»), possessing combined markers of «classic» necrosis and «classic» apoptosis. Detailed study of oncosis demonstrated that the elevation of the [Na+]i/[K+]i ratio is not a sufficient for its triggering. Non-rodent cell death is determined by the characteristic property of "sensitive" to ouabain α1-subunit of Na,K-ATPase. In this case, ouabain binding leads to enzyme conformational changes triggering the activation of p38 mitogen-activated protein kinases (MAPK) signaling. The survival of rodent cells with ouabain-«resistant» α1-subunit is connected with another conformational transition induced by ouabain binding that results in the activation of ERK 1/2 signaling pathway.
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Affiliation(s)
- Olga Dmitrievna Lopina
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Artem Mikhaylovich Tverskoi
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences (RAS), Moscow, Russia
- Laboratory of Biological Membranes, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Sergei Nikolaevich Orlov
- Laboratory of Biological Membranes, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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Orlov SN, Tverskoi AM, Sidorenko SV, Smolyaninova LV, Lopina OD, Dulin NO, Klimanova EA. Na,K-ATPase as a target for endogenous cardiotonic steroids: What's the evidence? Genes Dis 2020; 8:259-271. [PMID: 33997173 PMCID: PMC8093582 DOI: 10.1016/j.gendis.2020.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/24/2019] [Accepted: 01/09/2020] [Indexed: 12/17/2022] Open
Abstract
With an exception of few reports, the plasma concentration of ouabain and marinobufagenin, mostly studied cardiotonic steroids (CTS) assessed by immunoassay techniques, is less than 1 nM. During the last 3 decades, the implication of these endogenous CTS in the pathogenesis of hypertension and other volume-expanded disorders is widely disputed. The threshold for inhibition by CTS of human and rodent α1-Na,K-ATPase is ∼1 and 1000 nM, respectively, that rules out the functioning of endogenous CTS (ECTS) as natriuretic hormones and regulators of cell adhesion, cell-to-cell communication, gene transcription and translation, which are mediated by dissipation of the transmembrane gradients of monovalent cations. In several types of cells ouabain and marinobufagenin at concentrations corresponding to its plasma level activate Na,K-ATPase, decrease the [Na+]i/[K+]i-ratio and increase cell proliferation. Possible physiological significance and mechanism of non-canonical Na+i/K+i-dependent and Na+i/K+i-independent cell responses to CTS are discussed.
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Affiliation(s)
- Sergei N Orlov
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia.,Siberian State Medical University, Tomsk, 634050, Russia
| | | | - Svetlana V Sidorenko
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
| | - Larisa V Smolyaninova
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
| | - Olga D Lopina
- MV Lomonosov Moscow State University, Moscow, 119234, Russia
| | | | - Elizaveta A Klimanova
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
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Influence of Endogenous Cardiac Glycosides, Digoxin, and Marinobufagenin in the Physiology of Epithelial Cells. Cardiol Res Pract 2019; 2019:8646787. [PMID: 32089875 PMCID: PMC7024086 DOI: 10.1155/2019/8646787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Cardiac glycosides are a group of compounds widely known for their action in cardiac tissue, some of which have been found to be endogenously produced (ECG). We have previously studied the effect of ouabain, an endogenous cardiac glycoside, on the physiology of epithelial cells, and we have shown that in concentrations in the nanomolar range, it affects key properties of epithelial cells, such as tight junction, apical basolateral polarization, gap junctional intercellular communication (GJIC), and adherent junctions. In this work, we study the influence of digoxin and marinobufagenin, two other endogenously expressed cardiac glycosides, on GJIC as well as the degree of transepithelial tightness due to tight junction integrity (TJ). We evaluated GJIC by dye transfer assays and tight junction integrity by transepithelial electrical resistance (TER) measurements, as well as immunohistochemistry and western blot assays of expression of claudins 2 and 4. We found that both digoxin and marinobufagenin improve GJIC and significantly enhance the tightness of the tight junctions, as evaluated from TER measurements. Immunofluorescence assays show that both compounds promote enhanced basolateral localization of claudin-4 but not claudin 2, while densitometric analysis of western blot assays indicate a significantly increased expression of claudin 4. These changes, induced by digoxin and marinobufagenin on GJIC and TER, were not observed on MDCK-R, a modified MDCK cell line that has a genetically induced insensitive α1 subunit, indicating that Na-K-ATPase acts as a receptor mediating the actions of both ECG. Plus, the fact that the effect of both cardiac glycosides was suppressed by incubation with PP2, an inhibitor of c-Src kinase, PD98059, an inhibitor of mitogen extracellular kinase-1 and Y-27632, a selective inhibitor of ROCK, and a Rho-associated protein kinase, indicate altogether that the signaling pathways involved include c-Src and ERK1/2, as well as Rho-ROCK. These results widen and strengthen our general hypothesis that a very important physiological role of ECG is the control of the epithelial phenotype and the regulation of cell-cell contacts.
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Lava SAG, Bianchetti MG, Simonetti GD. Salt intake in children and its consequences on blood pressure. Pediatr Nephrol 2015; 30:1389-96. [PMID: 25127918 DOI: 10.1007/s00467-014-2931-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 02/07/2023]
Abstract
Sodium is the most abundant extracellular cation and therefore pivotal in determining fluid balance. At the beginning of life, a positive sodium balance is needed to grow. Newborns and preterm infants tend to lose sodium via their kidneys and therefore need adequate sodium intake. Among older children and adults, however, excessive salt intake leads to volume expansion and arterial hypertension. Children who are overweight, born preterm, or small for gestational age and African American children are at increased risk of developing high blood pressure due to a high salt intake because they are more likely to be salt sensitive. In the developed world, salt intake is generally above the recommended intake also among children. Although a positive sodium balance is needed for growth during the first year of life, in older children, a sodium-poor diet seems to have the same cardiovascular protective effects as among adults. This is relevant, since: (1) a blood pressure tracking phenomenon was recognized; (2) the development of taste preferences is important during childhood; and (3) salt intake is often associated with the consumption of sugar-sweetened beverages (predisposing children to weight gain).
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Affiliation(s)
- Sebastiano A G Lava
- Division of Pediatric Nephrology, University Children's Hospital Bern, Bern, Switzerland
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Estape ES, Torres-Negron I, Gonzalez L, Martinez-Maldonado M. A New Animal Model to Study Endogenous Cardiotonic Steroids and the Progression of Cardiovascular Events in Salt-Sensitive Hypertension. INTERNATIONAL ARCHIVES OF TRANSLATIONAL MEDICINE 2015; 1:002. [PMID: 26457335 PMCID: PMC4599712 DOI: 10.23937/2572-4142.1510002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Dahl salt-sensitive rat is a well-established model to study essential hypertension. We first described a subgroup of these rats based on the unique response pattern in systolic blood pressure during the first weeks of exposure to a high salt diet that included cataract formation. We classified this group as cataract-prone Dahl salt-sensitive rat. We also were able to predict and prevent cataract formation in these rats. Further studies showed an inhibition of lens Na, K-ATPase activity which may be in part responsible for the cataract formation. Other studies in Dahl salt-sensitive rats maintained on a high salt diet have also shown decreased Na, K-ATPase activity in several tissues and increased levels of endogenous circulating Na, K pump inhibitors. For over 20 years, endogenous cardiotonic steroids have been postulated to inhibit Na, K-ATPase in both humans as well as in experimental animal models of hypertension. Recent findings have shown results suggesting that there are several forms of cardiotonic steroids with minor differences in structural functionalities, site of production, and specific pump selectivity. We present original data that supports a role for cardiotonic steroids in disease progression related to increased salt-sensitivity. We found increased levels of free endogenous cardiotonic steroids in those rats that were classified as cataract-prone according to their initial systolic blood pressure response to a high salt intake when compared to non-cataract prone Dahl salt-sensitive rats and their control Dahl salt-resistant rats. The cataract-prone Dahl salt-sensitive rat is an animal model that can help and contribute to open a new door to possibly elucidate the role of endogenous cardiotonic steroids in the pathogenesis and progression of diseases related to salt-sensitive hypertension.
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Affiliation(s)
- Estela S Estape
- School of Health Professions, Medical Sciences Campus, University of Puerto Rico, Puerto Rico
| | - Ivette Torres-Negron
- School of Environmental Affairs, Universidad Metropolitana, Ana G Méndez University System, Puerto Rico
| | - Lorena Gonzalez
- Puerto Rico Clinical and Translational Research Consortium, Medical Sciences Campus, University of Puerto Rico, Puerto Rico
| | - Manuel Martinez-Maldonado
- Consultant, University of Puerto Rico, Medical Sciences Campus, Puerto Rico Clinical and Translational Research Consortium, Puerto Rico
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Muthuraman A, Kaur P, Kaur P, Singh H, Boparai PS. Ameliorative potential of vitamin P and digoxin in ischemic–reperfusion induced renal injury using the Langendorff apparatus. Life Sci 2015; 124:75-80. [DOI: 10.1016/j.lfs.2014.12.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 12/18/2014] [Accepted: 12/20/2014] [Indexed: 01/31/2023]
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Bricker NS, Cain CD, Shankel S. Natriuretic hormone: the ultimate determinant of the preservation of external sodium balance. Front Endocrinol (Lausanne) 2014; 5:212. [PMID: 25566186 PMCID: PMC4263174 DOI: 10.3389/fendo.2014.00212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 11/24/2014] [Indexed: 11/13/2022] Open
Abstract
The present manuscript focuses on a putative natriuretic hormone. It includes the history of a long-term search for the pure molecule, ranging from partial purification to synthesis. It includes a description of seven different bioassay systems used, a resume of the sequential steps in purification, and a summary of a series of experimental protocols employed in the effort to define the biologic properties of the inhibitor of sodium (Na) transport. Two closely related molecules were purified and synthesized. Both are xanthurenic acid derivatives (xanthurenic acid 8-O-β-D-glucoside and xanthurenic acid 8-O-sulfate). It is concluded that one or both of these two low molecular weight compounds (MW: 368 and 284) meet many of the criteria for the final modulator of Na excretion.
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Affiliation(s)
- Neal S. Bricker
- School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
- *Correspondence: Neal S. Bricker, 727 South Orange Grove Blvd., Suite 6, Pasadena, CA 91105, USA e-mail:
| | | | - Stewart Shankel
- Department of Medicine, School of Medicine, University of California at Riverside, Riverside, CA, USA
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