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Cardiovascular Disease in Obstructive Sleep Apnea: Putative Contributions of Mineralocorticoid Receptors. Int J Mol Sci 2023; 24:ijms24032245. [PMID: 36768567 PMCID: PMC9916750 DOI: 10.3390/ijms24032245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/12/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
Obstructive sleep apnea (OSA) is a chronic and highly prevalent condition that is associated with oxidative stress, inflammation, and fibrosis, leading to endothelial dysfunction, arterial stiffness, and vascular insulin resistance, resulting in increased cardiovascular disease and overall mortality rates. To date, OSA remains vastly underdiagnosed and undertreated, with conventional treatments yielding relatively discouraging results for improving cardiovascular outcomes in OSA patients. As such, a better mechanistic understanding of OSA-associated cardiovascular disease (CVD) and the development of novel adjuvant therapeutic targets are critically needed. It is well-established that inappropriate mineralocorticoid receptor (MR) activation in cardiovascular tissues plays a causal role in a multitude of CVD states. Clinical studies and experimental models of OSA lead to increased secretion of the MR ligand aldosterone and excessive MR activation. Furthermore, MR activation has been associated with worsened OSA prognosis. Despite these documented relationships, there have been no studies exploring the causal involvement of MR signaling in OSA-associated CVD. Further, scarce clinical studies have exclusively assessed the beneficial role of MR antagonists for the treatment of systemic hypertension commonly associated with OSA. Here, we provide a comprehensive overview of overlapping mechanistic pathways recruited in the context of MR activation- and OSA-induced CVD and propose MR-targeted therapy as a potential avenue to abrogate the deleterious cardiovascular consequences of OSA.
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Kołodziejczyk AM, Grala MM, Zimon A, Białkowska K, Walkowiak B, Komorowski P. Investigation of HUVEC response to exposure to PAMAM dendrimers – changes in cell elasticity and vesicles release. Nanotoxicology 2022; 16:375-392. [DOI: 10.1080/17435390.2022.2097138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Agnieszka Maria Kołodziejczyk
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd., Lodz, Poland
- Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd., Lodz, Poland
| | | | - Aleksandra Zimon
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd., Lodz, Poland
| | - Kamila Białkowska
- Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd., Lodz, Poland
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Bogdan Walkowiak
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd., Lodz, Poland
- Department of Biophysics, Institute of Materials Science and Engineering, Lodz University of Technology, Lodz, Poland
| | - Piotr Komorowski
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd., Lodz, Poland
- Department of Biophysics, Institute of Materials Science and Engineering, Lodz University of Technology, Lodz, Poland
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Bauersachs J, López-Andrés N. Mineralocorticoid receptor in cardiovascular diseases-Clinical trials and mechanistic insights. Br J Pharmacol 2021; 179:3119-3134. [PMID: 34643952 DOI: 10.1111/bph.15708] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/07/2021] [Accepted: 09/27/2021] [Indexed: 12/19/2022] Open
Abstract
Aldosterone binds to the mineralocorticoid receptor (NR3C2), a transcription factor of the nuclear receptor family, present in the kidney and in various other non-epithelial cells including the heart and the vasculature. Indeed, extra-renal pathophysiological effects of this hormone have been characterized, extending its actions to the cardiovascular system. A growing body of clinical and pre-clinical evidence suggests that mineralocorticoid receptor overactivation plays an important pathophysiological role in cardiovascular remodelling by promoting cardiac hypertrophy, fibrosis, arterial stiffness and in inflammation and oxidative stress. The following review article outlines the role of mineralocorticoid receptor in cardiovascular disease with a focus on myocardial remodelling and heart failure (HF) including clinical trials as well as cellular and animal studies.
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Affiliation(s)
- Johann Bauersachs
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Natalia López-Andrés
- Cardiovascular Translational Research. Navarrabiomed (Miguel Servet Foundation), Instituto de Investigación Sanitaria de Navarra (IdiSNA), Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Pamplona, Spain
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4
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Kolodziejczyk AM, Sokolowska P, Zimon A, Grala M, Rosowski M, Siatkowska M, Komorowski P, Walkowiak B. Dysfunction of endothelial cells exposed to nanomaterials assessed by atomic force spectroscopy. Micron 2021; 145:103062. [PMID: 33770641 DOI: 10.1016/j.micron.2021.103062] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/08/2021] [Accepted: 03/18/2021] [Indexed: 12/25/2022]
Abstract
The study of the impact of nanomaterials on endothelial cell elasticity with the atomic force spectroscopy (AFS) can be a significant model for assessing nanomaterials toxic effects in vitro. The mechanical properties of cells exposed to nanostructures can provide information not only about cellular nano and micro-structure, but also about cell physiology. The toxicity of nanostructures is an important issue which must be carefully considered when the optimal nanomaterial is defined. There are no universal properties characterizing such a nanomaterial, i.e. depending on the intended use, the requirements can be diverse. For example, for biomedical use a nanomaterial should not negatively affect the cells or should cause the expected therapeutic or diagnostic effects in justified cases. The present study was devoted to the effects of silver nanoparticles (SNPs), multi-walled carbon nanotubes (MWCNTs) and poly(amidoamine) (PAMAM) dendrimers of 4th generation on functioning of endothelial cells. Immortalized endothelial cells were exposed for 24 h to the tested nanomaterials used in concentrations reducing cellular viability to the levels of 90 % and 75 %. The innovative nature of our work is the comparison of cell elasticity performed with various AFS probes, which enabled detection of local and global elasticity alteration caused by the nanostructures. The obtained results demonstrated changes in elasticity of endothelial cell induced by the nanostructures, which were closely correlated with the level of cellular viability, forming of actin stress fibres and elevated levels of reactive oxygen species. Trend of changes in local and global elasticity of cells exposed to nanostructures was similar, but the magnitude of the response was dependent on the selected probe. SNPs and MWCNTs evoked cells stiffening, which was correlated with changes in production levels of reactive oxygen species (ROS) and the cytoskeletal alteration. Softening of cells exposed to PAMAM dendrimers correlated with increased number of apoptotic cells and ROS production levels. Based on the obtained results we conclude, that the structure and the type of nanostructure (nanoparticle) is essential for their localization inside the cells and for the toxic effect on the endothelial cells.
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Affiliation(s)
| | - Paulina Sokolowska
- Bionanopark Ltd, Dubois 114/116, 93-465, Lodz, Poland; Department of Pharmacology and Toxicology, Medical University of Lodz, Zeligowskiego 7 /9, 90-752, Lodz, Poland
| | | | | | | | | | - Piotr Komorowski
- Bionanopark Ltd, Dubois 114/116, 93-465, Lodz, Poland; Institute of Materials Science and Engineering, Lodz University of Technology, Stefanowskiego 1/15, 90-924, Lodz, Poland
| | - Bogdan Walkowiak
- Bionanopark Ltd, Dubois 114/116, 93-465, Lodz, Poland; Institute of Materials Science and Engineering, Lodz University of Technology, Stefanowskiego 1/15, 90-924, Lodz, Poland
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Liu G, Fu D, Tian H, Dai A. The mechanism of ions in pulmonary hypertension. Pulm Circ 2021; 11:2045894020987948. [PMID: 33614016 PMCID: PMC7869166 DOI: 10.1177/2045894020987948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/23/2020] [Indexed: 12/15/2022] Open
Abstract
Pulmonary hypertension(PH)is a kind of hemodynamic and pathophysiological state, in which the pulmonary artery pressure (PAP) rises above a certain threshold. The main pathological manifestation is pulmonary vasoconstriction and remodelling progressively. More and more studies have found that ions play a major role in the pathogenesis of PH. Many vasoactive substances, inflammatory mediators, transcription-inducing factors, apoptosis mediators, redox substances and translation modifiers can control the concentration of ions inside and outside the cell by regulating the activity of ion channels, which can regulate vascular contraction, cell proliferation, migration, apoptosis, inflammation and other functions. We all know that there are no effective drugs to treat PH. Ions are involved in the occurrence and development of PH, so it is necessary to clarify the mechanism of ions in PH as a therapeutic target for PH. The main ions involved in PH are calcium ion (Ca2+), potassium ion (K+), sodium ion (Na+) and chloride ion (Cl-). Here, we mainly discuss the distribution of these ions and their channels in pulmonary arteries and their role in the pathogenesis of PH.
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Affiliation(s)
- Guogu Liu
- Department of Graduate School, University of South China,
Hengyang, China
- Department of Respiratory Medicine, Hunan Provincial People’s
Hospital, Changsha, China
| | - Daiyan Fu
- Department of Respiratory Medicine, Hunan Provincial People’s
Hospital, Changsha, China
| | - Heshen Tian
- Department of Graduate School, University of South China,
Hengyang, China
- Department of Respiratory Medicine, Hunan Provincial People’s
Hospital, Changsha, China
| | - Aiguo Dai
- Department of Respiratory Diseases, Hunan University of Chinese
Medicine, Changsha, China
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6
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Li Q, Fung E. Multifaceted Functions of Epithelial Na + Channel in Modulating Blood Pressure. Hypertension 2019; 73:273-281. [PMID: 30580685 DOI: 10.1161/hypertensionaha.118.12330] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Qi Li
- From the Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong (Q.L., E.F.).,Laboratory for Heart Failure and Circulation Research, Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital, Hong Kong SAR (Q.L., E.F.)
| | - Erik Fung
- From the Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong (Q.L., E.F.).,Gerald Choa Cardiac Research Centre, Faculty of Medicine, The Chinese University of Hong Kong (E.F.).,Lui Che Woo Institute of Innovative Medicine, Faculty of Medicine, The Chinese University of Hong Kong (E.F.).,Laboratory for Heart Failure and Circulation Research, Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital, Hong Kong SAR (Q.L., E.F.)
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Abstract
PURPOSE OF REVIEW The review describes studies investigating the role of microRNAs in the signaling pathway of the mineralocorticoid hormone, aldosterone. RECENT FINDINGS Emerging evidence indicates that aldosterone alters the expression of microRNAs in target tissues thereby modulating the expression of key regulatory proteins. SUMMARY The mineralocorticoid hormone aldosterone is released by the adrenal glands in a homeostatic mechanism to regulate blood volume. The long-term renal action of aldosterone is to increase the retrieval of sodium from filtered plasma to restore blood pressure. Emerging evidence indicates aldosterone may alter noncoding RNAs (ncRNAs) to integrate this hormonal response in target tissue. Expression of the best characterized small ncRNAs, microRNAs, is regulated by aldosterone stimulation. MicroRNAs modulate protein expression at all steps in the renin-angiotensin-aldosterone-signaling (RAAS) system. In addition to acting as a rheostat to fine-tune protein levels in aldosterone-responsive cells, there is evidence that microRNAs down-regulate components of the signaling cascade as a feedback mechanism. The role of microRNAs is, therefore, as signal integrator, and damper in aldosterone signaling, which has implications in understating the RAAS system from both a physiological and pathophysiological perspective. Recent evidence for microRNA's role in RAAS signaling will be discussed.
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Ydegaard R, Andersen H, Oxlund CS, Jacobsen IA, Hansen PBL, Jürgensen JF, Peluso AA, Vanhoutte PM, Staehr M, Svenningsen P, Jensen BL. The acute blood pressure-lowering effect of amiloride is independent of endothelial ENaC and eNOS in humans and mice. Acta Physiol (Oxf) 2019; 225:e13189. [PMID: 30240139 DOI: 10.1111/apha.13189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 09/11/2018] [Accepted: 09/17/2018] [Indexed: 01/15/2023]
Abstract
AIMS The epithelial sodium channel (ENaC) is expressed in cultured endothelial cells and inhibitory coupling to eNOS activity has been proposed. The present study tested the hypothesis that ENaC blockers increase systemic NO-products and lower blood pressure in patients and mice, depending on eNOS. METHODS NO-products and cGMP were measured in diabetes patient urine and plasma samples before and after amiloride treatment (20-40 mg for two days, plasma n = 22, urine n = 12 and 5-10 mg for eight weeks, plasma n = 52, urine n = 55). Indwelling catheters were implanted in the femoral artery and vein in mice for continuous arterial blood pressure and heart rate recordings and infusion. RESULTS Treatment with amiloride for two days increased plasma and urine NO-products, while plasma cGMP decreased and urinary cGMP was unchanged in patient samples. Eight weeks of treatment with amiloride did not alter NO-products and cGMP. In mice, amiloride boli of 5, 50, and 500 µg/kg lowered heart rate and arterial blood pressure significantly and acutely. Benzamil had no effect on pressure and raised heart rate. In hypertensive eNOS-/- and L-NAME-treated mice, amiloride lowered blood pressure significantly. L-NAME infusion significantly decreased NO-products in plasma; amiloride and eNOS-deletion had no effect. An acetylcholine bolus resulted in acute blood pressure drop that was attenuated in eNOS-/- and L-NAME mice. ENaC subunit expressions were not detected consistently in human and mouse arteries and endothelial cells. CONCLUSION Amiloride has an acute hypotensive action not dependent on ENaC and eNOS and likely related to the heart.
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Affiliation(s)
- Rikke Ydegaard
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Henrik Andersen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | | | - Ib A. Jacobsen
- Department of Endocrinology; Odense University Hospital; Odense Denmark
| | - Pernille B. L. Hansen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
- Cardiovascular and Metabolic Disease, IMED Biotech Unit; AstraZeneca; Gothenburg Sweden
| | - Jonathan F. Jürgensen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Antonio Augusto Peluso
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Paul M. Vanhoutte
- Department of Pharmacology and Pharmacy; Hong Kong University; China
| | - Mette Staehr
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
| | - Boye L. Jensen
- Department of Cardiovascular and Renal Research, Institute for Molecular Medicine; University of Southern Denmark; Odense C Denmark
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9
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Kolodziejczyk A, Jakubowska A, Kucinska M, Wasiak T, Komorowski P, Makowski K, Walkowiak B. Sensing of silver nanoparticles on/in endothelial cells using atomic force spectroscopy. J Mol Recognit 2018; 31:e2723. [DOI: 10.1002/jmr.2723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/22/2018] [Accepted: 04/03/2018] [Indexed: 01/13/2023]
Affiliation(s)
| | | | - Magdalena Kucinska
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd; Łódź Poland
| | - Tomasz Wasiak
- Department of Molecular Biology; Faculty of Biomedical Sciences and Postgraduated Training, Medical University of Lodz; Łódź Poland
| | - Piotr Komorowski
- Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd; Łódź Poland
- Division of Biophysics; Institute of Materials Science, Lodz University of Technology; Łódź Poland
| | - Krzysztof Makowski
- Division of Biophysics; Institute of Materials Science, Lodz University of Technology; Łódź Poland
- Industrial Biotechnology Laboratory, Bionanopark Ldt.; Łódź Poland
| | - Bogdan Walkowiak
- Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd; Łódź Poland
- Division of Biophysics; Institute of Materials Science, Lodz University of Technology; Łódź Poland
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10
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Gkaliagkousi E, Anyfanti P, Triantafyllou A, Gavriilaki E, Nikolaidou B, Lazaridis A, Vamvakis A, Douma S. Aldosterone as a mediator of microvascular and macrovascular damage in a population of normotensive to early-stage hypertensive individuals. ACTA ACUST UNITED AC 2018; 12:50-57. [DOI: 10.1016/j.jash.2017.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/30/2017] [Accepted: 12/02/2017] [Indexed: 12/26/2022]
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11
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Martinez-Lemus LA, Aroor AR, Ramirez-Perez FI, Jia G, Habibi J, DeMarco VG, Barron B, Whaley-Connell A, Nistala R, Sowers JR. Amiloride Improves Endothelial Function and Reduces Vascular Stiffness in Female Mice Fed a Western Diet. Front Physiol 2017; 8:456. [PMID: 28713285 PMCID: PMC5492307 DOI: 10.3389/fphys.2017.00456] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/15/2017] [Indexed: 01/25/2023] Open
Abstract
Obese premenopausal women lose their sex related cardiovascular disease protection and develop greater arterial stiffening than age matched men. In female mice, we have shown that consumption of a Western diet (WD), high in fat and refined sugars, is associated with endothelial dysfunction and vascular stiffening, which occur via activation of mineralocorticoid receptors and associated increases in epithelial Na+ channel (ENaC) activity on endothelial cells (EnNaC). Herein our aim was to determine the effect that reducing EnNaC activity with a very-low-dose of amiloride would have on decreasing endothelial and arterial stiffness in young female mice consuming a WD. To this end, we fed female mice either a WD or control diet and treated them with or without a very-low-dose of the ENaC-inhibitor amiloride (1 mg/kg/day) in the drinking water for 20 weeks beginning at 4 weeks of age. Mice consuming a WD were heavier and had greater percent body fat, proteinuria, and aortic stiffness as assessed by pulse-wave velocity than those fed control diet. Treatment with amiloride did not affect body weight, body composition, blood pressure, urinary sodium excretion, or insulin sensitivity, but significantly reduced the development of endothelial and aortic stiffness, aortic fibrosis, aortic oxidative stress, and mesenteric resistance artery EnNaC abundance and proteinuria in WD-fed mice. Amiloride also improved endothelial-dependent vasodilatory responses in the resistance arteries of WD-fed mice. These results indicate that a very-low-dose of amiloride, not affecting blood pressure, is sufficient to improve endothelial function and reduce aortic stiffness in female mice fed a WD, and suggest that EnNaC-inhibition may be sufficient to ameliorate the pathological vascular stiffening effects of WD-induced obesity in females.
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Affiliation(s)
- Luis A Martinez-Lemus
- Dalton Cardiovascular Research Center, University of MissouriColumbia, MO, United States.,Department of Biological Engineering, University of MissouriColumbia, MO, United States.,Department of Medical Pharmacology and Physiology, University of MissouriColumbia, MO, United States.,Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States
| | - Annayya R Aroor
- Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
| | - Francisco I Ramirez-Perez
- Dalton Cardiovascular Research Center, University of MissouriColumbia, MO, United States.,Department of Biological Engineering, University of MissouriColumbia, MO, United States
| | - Guanghong Jia
- Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
| | - Javad Habibi
- Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
| | - Vincent G DeMarco
- Department of Medical Pharmacology and Physiology, University of MissouriColumbia, MO, United States.,Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
| | - Brady Barron
- Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
| | - Adam Whaley-Connell
- Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States.,Division of Nephrology and Hypertension, University of MissouriColumbia, MO, United States
| | - Ravi Nistala
- Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States.,Division of Nephrology and Hypertension, University of MissouriColumbia, MO, United States
| | - James R Sowers
- Dalton Cardiovascular Research Center, University of MissouriColumbia, MO, United States.,Research Service, Harry S. Truman Memorial Veterans' HospitalColumbia, MO, United States.,Diabetes and Cardiovascular Research Center, University of MissouriColumbia, MO, United States
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12
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Ong GSY, Young MJ. Mineralocorticoid regulation of cell function: the role of rapid signalling and gene transcription pathways. J Mol Endocrinol 2017; 58:R33-R57. [PMID: 27821439 DOI: 10.1530/jme-15-0318] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/06/2016] [Indexed: 12/22/2022]
Abstract
The mineralocorticoid receptor (MR) and mineralocorticoids regulate epithelial handling of electrolytes, and induces diverse effects on other tissues. Traditionally, the effects of MR were ascribed to ligand-receptor binding and activation of gene transcription. However, the MR also utilises a number of intracellular signalling cascades, often by transactivating unrelated receptors, to change cell function more rapidly. Although aldosterone is the physiological mineralocorticoid, it is not the sole ligand for MR. Tissue-selective and mineralocorticoid-specific effects are conferred through the enzyme 11β-hydroxysteroid dehydrogenase 2, cellular redox status and properties of the MR itself. Furthermore, not all aldosterone effects are mediated via MR, with implication of the involvement of other membrane-bound receptors such as GPER. This review will describe the ligands, receptors and intracellular mechanisms available for mineralocorticoid hormone and receptor signalling and illustrate their complex interactions in physiology and disease.
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Affiliation(s)
- Gregory S Y Ong
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of MedicineSchool of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Morag J Young
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of PhysiologySchool of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
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13
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Jeggle P, Hofschröer V, Maase M, Bertog M, Kusche‐Vihrog K. Aldosterone synthase knockout mouse as a model for sodium‐induced endothelial sodium channel up‐regulation in vascular endothelium. FASEB J 2015; 30:45-53. [DOI: 10.1096/fj.14-259606] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/13/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Pia Jeggle
- Institute of Physiology II, University of MunsterMunsterGermany
| | | | - Martina Maase
- Institute of Physiology II, University of MunsterMunsterGermany
| | - Marko Bertog
- Institut für Zelluläre und Molekulare Physiologie, Friedrich‐Alexander Universität Erlangen‐NürnbergErlangenGermany
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14
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Szymonski M, Targosz-Korecka M, Malek-Zietek KE. Nano-mechanical model of endothelial dysfunction for AFM-based diagnostics at the cellular level. Pharmacol Rep 2015; 67:728-35. [DOI: 10.1016/j.pharep.2015.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 12/17/2022]
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15
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Association between pre hemodialysis serum sodium concentration and blood pressure: results from a retrospective analysis from the international monitoring dialysis outcomes (MONDO) initiative. J Hum Hypertens 2015. [PMID: 26223346 DOI: 10.1038/jhh.2015.79] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A recent study from the United Kingdom indicates an association between pre hemodialysis (HD) serum sodium (SNa(+)) and systolic and diastolic blood pressure (SBP and DBP) in chronic HD patients. We extend this analysis to an international cohort of incident HD patients. The Monitoring Dialysis Outcomes initiative encompasses patients from 41 countries. Over 2 years monthly pre-HD SNa(+) levels were used as predictors of pre-HD SBP and DBP in a linear mixed model (LMM) adjusted for age, gender, interdialytic weight gain, diabetes, serum albumin and calcium. Similar models were constructed with DBP as outcome. Analyses were carried out stratified by continent (North and South America; Europe and Asia). LMMs were also constructed for the entire observation period of 2 years, and separately the first and the second year after HD initiation. We studied 17 050 incident patients and found SNa(+) to have a significant slope estimate in the LMM predicting pre-HD SBP and DBP (ranging from 0.22 to 0.29 and 0.10 to 0.21 mm Hg per mEq l(-1), respectively, between the continents). The findings were similar in subsets of SBP and SNa(+) tertiles, and separately analyzed for the first and second year. Our analysis shows an independent association between SNa, SBP and DBP in a large intercontinental database, indicating that this relation is a profound biological phenomenon in incident and prevalent HD patients, generalizable to an international level and independent of SBP and DBP magnitude.
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16
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Nijst P, Verbrugge FH, Grieten L, Dupont M, Steels P, Tang WHW, Mullens W. The pathophysiological role of interstitial sodium in heart failure. J Am Coll Cardiol 2015; 65:378-388. [PMID: 25634838 DOI: 10.1016/j.jacc.2014.11.025] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 01/05/2023]
Abstract
The current understanding of heart failure (HF) does not fully explain the spectrum of HF symptoms. Most HF hospitalizations are related to sodium (Na(+)) and fluid retention resulting from neurohumoral up-regulation. Recent insights suggest that Na(+) is not distributed in the body solely as a free cation, but that it is also bound to large interstitial glycosaminoglycan (GAG) networks in different tissues, which have an important regulatory function. In HF, high Na(+) intake and neurohumoral alterations disrupt GAG structure, leading to loss of the interstitial buffer capacity and disproportionate interstitial fluid accumulation. Moreover, a diminished endothelial GAG network (the endothelial glycocalyx) results in increased vascular resistance and disturbed endothelial nitric oxide production. New imaging modalities can help evaluate interstitial Na(+) and endothelial glycocalyx integrity. Furthermore, several therapies have been proven to stabilize interstitial GAG networks. Hence, a better appreciation of this new Na(+) "compartment" might improve current management of HF.
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Affiliation(s)
- Petra Nijst
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Frederik H Verbrugge
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Lars Grieten
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Doctoral School for Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Matthias Dupont
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Paul Steels
- Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - W H Wilson Tang
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio
| | - Wilfried Mullens
- Department of Cardiology, Ziekenhuis Oost-Limburg, Genk, Belgium; Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
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Kusche-Vihrog K, Schmitz B, Brand E. Salt controls endothelial and vascular phenotype. Pflugers Arch 2014; 467:499-512. [DOI: 10.1007/s00424-014-1657-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/11/2014] [Accepted: 11/14/2014] [Indexed: 01/11/2023]
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Schmitz B, Brand SM, Brand E. Aldosterone signaling and soluble adenylyl cyclase-a nexus for the kidney and vascular endothelium. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2601-9. [PMID: 24907563 DOI: 10.1016/j.bbadis.2014.05.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/23/2014] [Accepted: 05/28/2014] [Indexed: 12/14/2022]
Abstract
The steroid hormone aldosterone regulates the reabsorption of water and ions in the kidney and plays a central role in blood pressure regulation and homeostasis. In recent years, the vascular endothelium has been established as an important aldosterone target organ with major implications in renal and cardiovascular health and disease. Different lines of evidence suggest that the calcium- and bicarbonate-activated soluble adenylyl cyclase (sAC) is a novel mediator of aldosterone signaling in both the kidney and vascular endothelium. This review summarizes our current understanding of the molecular mechanisms of sAC gene expression regulation in the kidney and vascular endothelium and outlines the potential clinical implications of sAC in chronic kidney disease and cardiovascular disease. This review is part of a special issue entitled: The role of soluble adenylyl cyclase in health and disease. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- Boris Schmitz
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Horstmarer Landweg 39, 48149 Muenster, Germany; Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany
| | - Stefan-Martin Brand
- Institute of Sports Medicine, Molecular Genetics of Cardiovascular Disease, University Hospital Muenster, Horstmarer Landweg 39, 48149 Muenster, Germany
| | - Eva Brand
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany.
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Maron BA, Leopold JA. The role of the renin-angiotensin-aldosterone system in the pathobiology of pulmonary arterial hypertension (2013 Grover Conference series). Pulm Circ 2014; 4:200-10. [PMID: 25006439 PMCID: PMC4070776 DOI: 10.1086/675984] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 01/17/2014] [Indexed: 12/20/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is associated with aberrant pulmonary vascular remodeling that leads to increased pulmonary artery pressure, pulmonary vascular resistance, and right ventricular dysfunction. There is now accumulating evidence that the renin-angiotensin-aldosterone system is activated and contributes to cardiopulmonary remodeling that occurs in PAH. Increased plasma and lung tissue levels of angiotensin and aldosterone have been detected in experimental models of PAH and shown to correlate with cardiopulmonary hemodynamics and pulmonary vascular remodeling. These processes are abrogated by treatment with angiotensin receptor or mineralocorticoid receptor antagonists. At a cellular level, angiotensin and aldosterone activate oxidant stress signaling pathways that decrease levels of bioavailable nitric oxide, increase inflammation, and promote cell proliferation, migration, extracellular matrix remodeling, and fibrosis. Clinically, enhanced renin-angiotensin activity and elevated levels of aldosterone have been detected in patients with PAH, which suggests a role for angiotensin and mineralocorticoid receptor antagonists in the treatment of PAH. This review will examine the current evidence linking renin-angiotensin-aldosterone system activation to PAH with an emphasis on the cellular and molecular mechanisms that are modulated by aldosterone and may be of importance for the pathobiology of PAH.
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Affiliation(s)
- Bradley A. Maron
- Brigham and Women’s Hospital, Division of Cardiovascular Medicine, Boston, Massachusetts, USA
- Veterans Affairs Boston Healthcare System, Department of Cardiology, 1400 VFW Parkway, Boston, Massachusetts, USA
| | - Jane A. Leopold
- Brigham and Women’s Hospital, Division of Cardiovascular Medicine, Boston, Massachusetts, USA
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20
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Abstract
The mechanical characteristics of endothelial cells reveal four distinct compartments, namely glycocalyx, cell cortex, cytoplasm and nucleus. There is accumulating evidence that endothelial nanomechanics of these individual compartments control vascular physiology. Depending on protein composition, filament formation and interaction with cross-linker proteins, these four compartments determine endothelial stiffness. Structural organization and mechanical properties directly influence physiological processes such as endothelial barrier function, nitric oxide release and gene expression. This review will focus on endothelial nanomechanics and its impact on vascular function.
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21
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22
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Warnock DG, Kusche-Vihrog K, Tarjus A, Sheng S, Oberleithner H, Kleyman TR, Jaisser F. Blood pressure and amiloride-sensitive sodium channels in vascular and renal cells. Nat Rev Nephrol 2014; 10:146-57. [PMID: 24419567 DOI: 10.1038/nrneph.2013.275] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sodium transport in the distal nephron is mediated by epithelial sodium channel activity. Proteolytic processing of external domains and inhibition with increased sodium concentrations are important regulatory features of epithelial sodium channel complexes expressed in the distal nephron. By contrast, sodium channels expressed in the vascular system are activated by increased external sodium concentrations, which results in changes in the mechanical properties and function of endothelial cells. Mechanosensitivity and shear stress affect both epithelial and vascular sodium channel activity. Guyton's hypothesis stated that blood pressure control is critically dependent on vascular tone and fluid handling by the kidney. The synergistic effects, and complementary regulation, of the epithelial and vascular systems are consistent with the Guytonian model of volume and blood pressure regulation, and probably reflect sequential evolution of the two systems. The integration of vascular tone, renal perfusion and regulation of renal sodium reabsorption is the central underpinning of the Guytonian model. In this Review, we focus on the expression and regulation of sodium channels, and we outline the emerging evidence that describes the central role of amiloride-sensitive sodium channels in the efferent (vascular) and afferent (epithelial) arms of this homeostatic system.
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Affiliation(s)
- David G Warnock
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 34294-0007, USA
| | - Kristina Kusche-Vihrog
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Antoine Tarjus
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Shaohu Sheng
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Hans Oberleithner
- Institut für Physiologie II, Westfälische Wilhelms Universität, Robert-Koch-Straße 27, 48149 Münster, Germany
| | - Thomas R Kleyman
- Renal and Electrolyte Division, Department of Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Frederic Jaisser
- INSERM U872 Team 1, Centre de Recherche des Cordeliers, Université René Descartes, Université Pierre et Marie Curie, 15 rue de l'Ecole de Médecine, 75006 Paris, France
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23
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Kusche-Vihrog K, Jeggle P, Oberleithner H. The role of ENaC in vascular endothelium. Pflugers Arch 2013; 466:851-9. [PMID: 24046153 DOI: 10.1007/s00424-013-1356-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/09/2013] [Accepted: 09/09/2013] [Indexed: 12/31/2022]
Abstract
Once upon a time, the expression of the epithelial sodium channel (ENaC) was mainly assigned to the kidneys, colon and sweat glands where it was considered to be the main determinant of sodium homeostasis. Recent, though indirect, evidence for the possible existence of ENaC in a non-epithelial tissue was derived from the observation that the vascular endothelium is a target for aldosterone. Inhibitory actions of the intracellular aldosterone receptors by spironolactone and, more directly, by ENaC blockers such as amiloride supported this view. Shortly after, direct data on the expression of ENaC in vascular endothelium could be demonstrated. There, endothelial ENaC (EnNaC) could be defined as a major regulator of cellular mechanics which is a critical parameter in differentiating between vascular function and dysfunction. Foremost, the mechanical stiffness of the endothelial cell cortex, a layer 50-200 nm beneath the plasma membrane, has been shown to play a crucial role as it controls the production of the endothelium-derived vasodilator nitric oxide (NO) which directly affects the tone of the vascular smooth muscle cells. In contrast to soft endothelial cells, stiff endothelial cells release reduced amounts of NO, the hallmark of endothelial dysfunction. Thus, the combination of endothelial stiffness and myogenic tone might increase the peripheral vascular resistance. An elevation of arterial blood pressure is supposed to be the consequence of such functional changes. In this review, EnNaC is discussed as an aldosterone-regulated plasma membrane protein of the vascular endothelium that could significantly contribute to maintaining of an appropriate arterial blood pressure but, if overexpressed, could participate in the pathogenesis of arterial hypertension.
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Affiliation(s)
- Kristina Kusche-Vihrog
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany,
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24
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Kolodziejczyk AM, Brzezinka GD, Khurana K, Targosz-Korecka M, Szymonski M. Nanomechanical sensing of the endothelial cell response to anti-inflammatory action of 1-methylnicotinamide chloride. Int J Nanomedicine 2013; 8:2757-67. [PMID: 23946648 PMCID: PMC3738255 DOI: 10.2147/ijn.s46936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND There is increasing evidence that cell elastic properties should change considerably in response to chemical agents affecting the physiological state of the endothelium. In this work, a novel assay for testing prospective endothelium-targeted agents in vitro is presented. MATERIALS AND METHODS The proposed methodology is based on nanoindentation spectroscopy using an atomic force microscope tip, which allows for quantitative evaluation of cell stiffness. As an example, we chose a pyridine derivative, 1-methylnicotinamide chloride (MNA), known to have antithrombotic and anti-inflammatory properties, as reported in recent in vivo experiments. RESULTS First, we determined a concentration range of MNA in which physiological parameters of the endothelial cells in vitro are not affected. Then, cell dysfunction was induced by incubation with tumor necrosis factor-alpha (TNF-α) and the cellular response to MNA treatment after TNF-α incubation was studied. In parallel to the nanoindentation spectroscopy, the endothelium phenotype was characterized using a fluorescence spectroscopy with F-actin labeling, and biochemical methods, such as secretion measurements of both nitric oxide (NO), and prostacyclin (PGI2) regulatory agents. CONCLUSION We found that MNA could reverse the dysfunction of the endothelium caused by inflammation, if applied in the proper time and to the concentration scheme established in our investigations. A surprisingly close correlation was found between effective Young's modulus of the cells and actin polymerization/depolymerization processes in the endothelium cortical cytoskeleton, as well as NO and PGI2 levels. These results allow us to construct the physiological model of sequential intracellular pathways activated in the endothelium by MNA.
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Affiliation(s)
- A M Kolodziejczyk
- Research Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Krakow, Poland
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Toda N, Nakanishi S, Tanabe S. Aldosterone affects blood flow and vascular tone regulated by endothelium-derived NO: therapeutic implications. Br J Pharmacol 2013. [PMID: 23190073 DOI: 10.1111/j.1476-5381.2012.02194.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aldosterone, in doses inappropriate to the salt status, plays an important role in the development of cardiovascular injury, including endothelial dysfunction, independent of its hypertensive effects. Acute non-genomic effects of aldosterone acting on mineralocorticoid receptors are inconsistent in healthy humans: vasoconstriction or forearm blood flow decrease via endothelial dysfunction, vasodilatation mediated by increased NO actions, or no effects. However, in studies with experimental animals, aldosterone mostly enhances vasodilatation mediated by endothelium-derived NO. Chronic exposure to aldosterone, which induces genomic responses, results in impairments of endothelial function through decreased NO synthesis and action in healthy individuals, experimental animals and isolated endothelial cells. Chronic aldosterone reduces NO release from isolated human endothelial cells only when extracellular sodium is raised. Oxidative stress is involved in the impairment of endothelial function by promoting NO degradation. Aldosterone liberates endothelin-1 (ET-1) from endothelial cells, which elicits ET(A) receptor-mediated vasoconstriction by inhibiting endothelial NO synthesis and action and through its own direct vasoconstrictor action. Ca(2+) flux through T-type Ca(2+) channels activates aldosterone synthesis and thus enhances unwanted effects of aldosterone on the endothelium. Mineralocorticoid receptor inhibitors, ET(A) receptor antagonists and T-type Ca(2) + channel blockers appear to diminish the pathophysiological participation of aldosterone in cardiovascular disease and exert beneficial actions on bioavailability of endothelium-derived NO, particularly in resistant hypertension and aldosteronism.
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Affiliation(s)
- Noboru Toda
- Toyama Institute for Cardiovascular Pharmacology Research, Osaka, Japan.
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26
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Jeong KH, Lee SH. A new technical approach to monitor the cellular physiology by atomic force microscopy. Electrolyte Blood Press 2013; 10:7-11. [PMID: 23508877 PMCID: PMC3597918 DOI: 10.5049/ebp.2012.10.1.7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Accepted: 12/12/2012] [Indexed: 11/05/2022] Open
Abstract
Atomic force microscopy (AFM) has become an important medical and biological tool for non-invasive imaging and measuring the mechanical changes of cells since its invention by Binnig et al. AFM can be used to investigate the mechanical properties of cellular events in individual living cells on a nanoscale level. In addition, the dynamic cellular movements induced by biochemical activation of specific materials can be detected in real time with three dimensional resolution. Force measurement with the use of AFM has become the tool of choice to monitor the mechanical changes of variable cellular events. In addition, the AFM approach can be applied to measure cellular adhesion properties. Moreover, the information gathered from AFM is important to understanding the mechanisms related to cellular movement and mechanical regulation. This review will discuss recent contributions of AFM to cellular physiology with a focus on monitoring the effects of antihypertensive agents in kidney cells.
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Affiliation(s)
- Kyung Hwan Jeong
- Department of Internal Medicine, College of Medicine, Kyung Hee University, Seoul, Korea
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27
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Briet M, Schiffrin EL. Vascular actions of aldosterone. J Vasc Res 2012; 50:89-99. [PMID: 23172373 DOI: 10.1159/000345243] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/18/2012] [Indexed: 02/03/2023] Open
Abstract
Aldosterone exerts direct effects on the vascular system by inducing oxidative stress, inflammation, hypertrophic remodeling, fibrosis, and endothelial dysfunction. Aldosterone exerts its effects through genomic and nongenomic pathways in a mineralocorticoid receptor (MR)-dependent or independent manner. Other aldosterone receptors such as GPR30 have been identified. A tight relation exists between the aldosterone and angiotensin II pathways, as well as with the endothelin-1 system. There is a correlation between plasma levels of aldosterone and cardiovascular risk. Recently, an increasing body of evidence has underlined the importance of aldosterone in cardiovascular complications associated with the metabolic syndrome, such as arterial remodeling and endothelial dysfunction. Blockade of MR is an increasingly used evidence-based therapy for many forms of cardiovascular disease, including hypertension, heart failure, chronic kidney disease, and diabetes mellitus.
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Affiliation(s)
- Marie Briet
- Université Paris Descartes, Faculté de Medicine, Assistance Publique des Hôpitaux de Paris, Hôpital Européen Georges Pompidou, INSERM CIC 9201, Paris, France
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28
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Shi X, Zhang X, Xia T, Fang X. Living cell study at the single-molecule and single-cell levels by atomic force microscopy. Nanomedicine (Lond) 2012; 7:1625-37. [DOI: 10.2217/nnm.12.130] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Atomic force microscopy (AFM) has been emerging as a multifunctional molecular tool in nanobiology and nanomedicine. This review summarizes the recent advances in AFM study of living mammalian cells at the single-molecule and single-cell levels. Besides nanoscale imaging of cell membrane structure, AFM-based force measurements on living cells are mainly discussed. These include the development and application of single-molecule force spectroscopy to investigate ligand–receptor binding strength and dissociation dynamics, and the characterization of cell mechanical properties in a physiological environment. Molecular manipulation of cells by AFM to change the cellular process is also described. Living-cell AFM study offers a new approach to understand the molecular mechanisms of cell function, disease development and drug effect, as well as to develop new strategies to achieve single-cell-based diagnosis.
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Affiliation(s)
- Xiaoli Shi
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Xuejie Zhang
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Tie Xia
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
| | - Xiaohong Fang
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, 2 Zhongguancun North First Street, 100190 Beijing, PR China
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29
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Jeong KH, Lee TW, Ihm CG, Moon JY, Lee GJ, Park HK, Lee SH. Real-time monitoring of the effects of telmisartan on angiotensin II-induced mechanical changes in live mesangial cells using atomic force microscopy. Kidney Blood Press Res 2012; 35:573-82. [PMID: 22890312 DOI: 10.1159/000339175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 04/27/2012] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND/AIMS Recent studies have shown that angiotensin II (Ang II) type 1 receptor blockers (ARB) may provide renal protection independent of their blood pressure-lowering effect. However, evidence for this comes from indirect methods, such as genetic or protein expression studies. In this study, we hypothesized that telmisartan, a specific ARB, applied to Ang II-stimulated mesangial cell (MC) would exert a renoprotective effect via modulation of MCs' mechanical properties. METHODS We investigated the effect of telmisartan on Ang II-induced changes in MCs utilizing real-time atomic force microscopy (AFM) imaging and force-distance curve measurements. RESULTS Real-time AFM images of live MCs demonstrated that cells contracted towards the center after Ang II exposure, and telmisartan treatment abolished this change. Cellular spring constants showed that telmisartan prevented Ang II-induced MC stiffening (Ang II: 0.109 ± 0.019 N/m, Ang II + telmisartan: 0.051 ± 0.016 N/m, p < 0.005). Telmisartan-treated MCs had a significantly lower adhesion force than those of the control group (control: 0.49 ± 0.22 nN, telmisartan: 0.22 ± 0.06 nN, Ang II: 0.40 ± 0.25 nN, Ang II + telmisartan: 0.27 ± 0.14 nN, p < 0.005). These results demonstrate that the dynamic contraction and mechanical properties of Ang II-stimulated MCs are restored by telmisartan. CONCLUSIONS We report for the first time the use of AFM force-distance curves on live MCs to directly monitor changes in surface adhesion and stiffness of cells after treatment with telmisartan in real time.
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Affiliation(s)
- Kyung-Hwan Jeong
- Department of Nephrology, College of Medicine, Kyung Hee University, Seoul, Korea
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30
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Fels J, Jeggle P, Kusche-Vihrog K, Oberleithner H. Cortical actin nanodynamics determines nitric oxide release in vascular endothelium. PLoS One 2012; 7:e41520. [PMID: 22844486 PMCID: PMC3402397 DOI: 10.1371/journal.pone.0041520] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/21/2012] [Indexed: 02/05/2023] Open
Abstract
The release of the main vasodilator nitric oxide (NO) by the endothelial NO synthase (eNOS) is a hallmark of endothelial function. We aim at elucidating the underlying mechanism how eNOS activity depends on cortical stiffness (К(cortex)) of living endothelial cells. It is hypothesized that cortical actin dynamics determines К(cortex) and directly influences eNOS activity. By combined atomic force microscopy and fluorescence imaging we generated mechanical and optical sections of single living cells. This approach allows the discrimination between К(cortex) and bulk cell stiffness (К(bulk)) and, additionally, the simultaneous analysis of submembranous actin web dynamics. We show that К(cortex) softens when cortical F-actin depolymerizes and that this shift from a gel-like stiff cortex to a soft G-actin rich layer, triggers the stiffness-sensitive eNOS activity. The results implicate that stiffness changes in the ∼100 nm phase of the submembranous actin web, without affecting К(bulk), regulate NO release and thus determines endothelial function.
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Affiliation(s)
- Johannes Fels
- Institute of Physiology II, University of Muenster, Muenster, Germany.
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31
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Genetic variants in serum and glucocortocoid regulated kinase 1, a regulator of the epithelial sodium channel, are associated with ischaemic stroke. J Hypertens 2011; 29:884-9. [DOI: 10.1097/hjh.0b013e3283455117] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Kliche K, Jeggle P, Pavenstädt H, Oberleithner H. Role of cellular mechanics in the function and life span of vascular endothelium. Pflugers Arch 2011; 462:209-17. [DOI: 10.1007/s00424-011-0929-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 01/13/2011] [Accepted: 01/16/2011] [Indexed: 01/17/2023]
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Kusche-Vihrog K, Urbanova K, Blanqué A, Wilhelmi M, Schillers H, Kliche K, Pavenstädt H, Brand E, Oberleithner H. C-reactive protein makes human endothelium stiff and tight. Hypertension 2010; 57:231-7. [PMID: 21149827 DOI: 10.1161/hypertensionaha.110.163444] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Elevation of C-reactive protein (CRP) in human blood accompanies inflammatory processes, including cardiovascular diseases. There is increasing evidence that the acute-phase reactant CRP is not only a passive marker protein for systemic inflammation but also affects the vascular system. Further, CRP is an independent risk factor for atherosclerosis and the development of hypertension. Another crucial player in atherosclerotic processes is the mineralocorticoid hormone aldosterone. Even in low physiological concentrations, it stimulates the expression and membrane insertion of the epithelial sodium channel, thereby increasing the mechanical stiffness of endothelial cells. This contributes to the progression of endothelial dysfunction. In the present study, the hypothesis was tested that the acute application of CRP (25 mg/L), in presence of aldosterone (0.5 nmol/L; 24 hour incubation), modifies the mechanical stiffness and permeability of the endothelium. We found that endothelial cells stiffen in response to CRP. In parallel, endothelial epithelial sodium channel is inserted into the plasma membrane, while, surprisingly, the endothelial permeability decreases. CRP actions are prevented either by the inhibition of the intracellular aldosterone receptors using spironolactone (5 nmol/L) or by the inactivation of epithelial sodium channel using specific blockers. In contrast, inhibition of the release of the vasodilating gas nitric oxide via blockade of the phosphoinositide 3-kinase/Akt pathway has no effect on the CRP-induced stiffening of endothelial cells. The data indicate that CRP enhances the effects of aldosterone on the mechanical properties of the endothelium. Thus, CRP could counteract any decrease in arterial blood pressure that accompanies severe acute inflammatory processes.
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Kusche-Vihrog K, Callies C, Fels J, Oberleithner H. The epithelial sodium channel (ENaC): Mediator of the aldosterone response in the vascular endothelium? Steroids 2010; 75:544-9. [PMID: 19778545 DOI: 10.1016/j.steroids.2009.09.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 09/11/2009] [Accepted: 09/14/2009] [Indexed: 12/15/2022]
Abstract
In the kidney the epithelial sodium channel (ENaC) is regulated by the mineralocorticoid hormone aldosterone, which is essential for long-term blood pressure control. Evidence has accumulated showing that ENaC is expressed in endothelial cells. Moreover, its activity modifies the biomechanical properties of the endothelium. Therefore, the vascular system is also an important target for aldosterone and responds to the hormone with an increase in cell volume, surface area, and mechanical stiffness. These changes occur in a concerted fashion from minutes to hours and can be prevented by the specific sodium channel blocker amiloride and the mineralocorticoid receptor (MR) blocker spironolactone. Aldosterone acts on cells of the vascular system via genomic and non-genomic pathways. There is evidence that the classical cytosolic MR could mediate both types of response. Using a nanosensor covalently linked to aldosterone, binding sites at the plasma membrane were identified by atomic force microscopy. The interaction of aldosterone and this newly identified surface receptor could precede the slow classic genomic aldosterone response resulting in fast activation of endothelial ENaC. Recent data suggest that aldosterone-induced ENaC activation initiates a sequence of cellular events leading to a reduced release of vasodilating nitric oxide. We propose a model in which ENaC is the key mediator of aldosterone-dependent blood pressure control in the vascular endothelium.
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35
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Boschitsch E, Mayerhofer S, Magometschnigg D. Hypertension in women: the role of progesterone and aldosterone. Climacteric 2010; 13:307-13. [DOI: 10.3109/13697131003624649] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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36
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Fels J, Oberleithner H, Kusche-Vihrog K. Ménage à trois: aldosterone, sodium and nitric oxide in vascular endothelium. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1193-202. [PMID: 20302930 DOI: 10.1016/j.bbadis.2010.03.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 12/16/2022]
Abstract
Aldosterone, a mineralocorticoid hormone mainly synthesized in the adrenal cortex, has been recognized to be a regulator of cell mechanics. Recent data from a number of laboratories implicate that, besides kidney, the cardiovascular system is an important target for aldosterone. In the endothelium, it promotes the expression of epithelial sodium channels (ENaC) and modifies the morphology of cells in terms of mechanical stiffness, surface area and volume. Additionally, it renders the cells highly sensitive to small changes in extracellular sodium and potassium. In this context, the time course of aldosterone action is pivotal. In the fast (seconds to minutes), non-genomic signalling pathway vascular endothelial cells respond to aldosterone with transient swelling, softening and insertion of ENaC in the apical plasma membrane. In parallel, nitric oxide (NO) is released from the cells. In the long-term (hours), aldosterone has opposite effects: The mechanical stiffness increases, the cells shrink and NO production decreases. This leads to the conclusion that both the physiology and pathophysiology of aldosterone action in the vascular endothelium are closely related. Aldosterone, at concentrations in the physiological range and over limited time periods can stabilize blood pressure and regulate tissue perfusion while chronically high concentrations of this hormone over extended time periods impair sodium homeostasis promoting endothelial dysfunction and the development of tissue fibrosis.
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Affiliation(s)
- Johannes Fels
- Institute of Physiology II, University of Münster, Germany
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Abstract
In the setting of primary aldosteronism, elevated aldosterone levels are associated with increased blood pressure. Aldosterone concentrations within the normal range, however, can also alter blood pressure. Furthermore, the aldosterone-to-renin ratio, an indicator of aldosterone excess, is associated with hypertension, even in patients without excessive absolute aldosterone levels. In this Review we assess the data on the role of aldosterone in the development and maintenance of hypertension. We provide an overview of the complex crosstalk between genetic and environmental factors, and about aldosterone-mediated arterial hypertension and target organ damage. The discussion is organized according to major targets of aldosterone action: the collecting duct in the kidney, the vasculature and the central nervous system. The antihypertensive efficacy of mineralocorticoid-receptor blockers, even in patients with aldosterone values in the normal range, supports the evidence that aldosterone plays a part in blood pressure elevation in the absence of primary aldosteronism.
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Affiliation(s)
- Andreas Tomaschitz
- Division of Endocrinology and Nuclear Medicine, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
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Cachofeiro V, López-Andrés N, Miana M, Martín-Fernández B, de las Heras N, Martínez E, Lahera V, Fortuño MA. Aldosterone and the cardiovascular system: a dangerous association. Horm Mol Biol Clin Investig 2010; 4:539-48. [DOI: 10.1515/hmbci.2010.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 10/11/2010] [Indexed: 11/15/2022]
Abstract
AbstractInitial studies have focussed on the actions of aldosterone in renal electrolyte handling and, as a consequence, blood pressure control. More recently, attention has primarily been focussed on its actions on the heart and vascular system, where it is locally produced. Aldosterone by binding mineralocorticoid receptors causes oxidative stress, fibrosis and triggers an inflammatory response in the cardiovascular system. All these effects could be underlying the role of aldo-sterone on cardiac and vascular remodelling associated with different pathological situations. At the vascular level, aldo-sterone affects endothelial function because administration of aldosterone to rats impaired endothelium-dependent relaxations. In addition, the administration of mineralocorticoid receptor antagonists ameliorates endothelium-dependent relaxation in models of both hypertension and atherosclerosis, and in patients with heart failure. Several mechanisms can participate in this effect, including production of vasoconstrictor factors and a reduction in nitric oxide levels. This reduction can involve both a decrease in its production as well as an increase in its degradation by reactive oxygen species. Aldosterone can produce oxidative stress by the activation of transcription factors such as the NF-κB system, which can also trigger an inflammatory process through the production of different cytokines. At cardiac level, high levels of aldosterone can also adversely impact heart function by producing cardiac hypertrophy, diastolic dysfunction and electrical remodelling through changes in ionic channels. All these effects can explain the beneficial effect of mineralocorticoid blockade in the cardiovascular system.
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Callies C, Schön P, Liashkovich I, Stock C, Kusche-Vihrog K, Fels J, Sträter AS, Oberleithner H. Simultaneous mechanical stiffness and electrical potential measurements of living vascular endothelial cells using combined atomic force and epifluorescence microscopy. NANOTECHNOLOGY 2009; 20:175104. [PMID: 19420584 DOI: 10.1088/0957-4484/20/17/175104] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The degree of mechanical stiffness of vascular endothelial cells determines the endogenous production of the vasodilating gas nitric oxide (NO). However, the underlying mechanisms are not yet understood. Experiments on vascular endothelial cells suggest that the electrical plasma membrane potential is involved in this regulatory process. To test this hypothesis we developed a technique that simultaneously measures the electrical membrane potential and stiffness of vascular endothelial cells (GM7373 cell line derived from bovine aortic endothelium) under continuous perfusion with physiological electrolyte solution. The cellular stiffness was determined by nano-indentation using an atomic force microscope (AFM) while the electrical membrane potential was measured with bis-oxonol, a voltage-reporting fluorescent dye. These two methods were combined using an AFM attached to an epifluorescence microscope. The electrical membrane potential and mechanical stiffness of the same cell were continuously recorded for a time span of 5 min. Fast fluctuations (in the range of seconds) of both the electrical membrane potential and mechanical stiffness could be observed that were not related to each other. In contrast, slow cell depolarizations (in the range of minutes) were paralleled by significant increases in mechanical stiffness. In conclusion, using the combined AFM-fluorescence technique we monitored for the first time simultaneously the electrical plasma membrane potential and mechanical stiffness in a living cell. Vascular endothelial cells exhibit oscillatory non-synchronized waves of electrical potential and mechanical stiffness. The sustained membrane depolarization, however, is paralleled by a concomitant increase of cell stiffness. The described method is applicable for any fluorophore, which opens new perspectives in biomedical research.
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Affiliation(s)
- Chiara Callies
- Institute of Physiology II, University of Münster, Germany.
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Cachofeiro V, Miana M, de Las Heras N, Martín-Fernández B, Ballesteros S, Fernández-Tresguerres J, Lahera V. Aldosterone and the vascular system. J Steroid Biochem Mol Biol 2008; 109:331-5. [PMID: 18400490 DOI: 10.1016/j.jsbmb.2008.03.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Aldosterone can act in different tissues exerting physiological and pathological effects. At the vascular level, aldosterone affects endothelial function since administration of aldosterone impaired endothelium-dependent relaxations. In addition, the administration of mineralocorticoid receptor antagonists ameliorate relaxation to acetylcholine in models of both hypertension and atherosclerosis and in patients with heart failure. A reduction in nitric oxide levels seems to be the main mechanism underlying this effect due to a reduction in its production as well as an increase in its degradation by reactive oxygen species. Aldosterone is a pro-inflammatory factor that can participate in the vascular inflammatory process associated with different pathologies including hypertension through activation of the NFkappaB system, which mediates the vascular production of different cytokines. This mineralocorticoid also participates in the vascular remodeling observed in hypertensive rats since the administration of eplerenone improved the media-to-lumen ratio in these animals. This effect seems to be due to an increase in extracellular matrix. In summary, aldosterone through mineralocorticoid receptors can participate in the vascular damage associated with different pathologies including hypertension through its prooxidant, pro-inflammatory and profibrotic effects that triggered endothelial dysfunction, an inflammatory process and vascular remodeling.
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Affiliation(s)
- Victoria Cachofeiro
- Department of Physiology, School of Medicine, Universidad Complutense, Madrid, Spain.
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De BK, Dutta D, Som R, Biswas PK, Pal SK, Biswas A. Hemodynamic effects of propranolol with spironolactone in patients with variceal bleeds: A randomized controlled trial. World J Gastroenterol 2008; 14:1908-13. [PMID: 18350631 PMCID: PMC2700421 DOI: 10.3748/wjg.14.1908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the hemodynamic effects of spironolactone with propranolol vs propranolol alone in the secondary prophylaxis of variceal bleeding.
METHODS: Thirty-five cirrhotics with variceal bleeding randomly received propranolol (n = 17: Group A) or spironolactone plus propranolol (n = 18: Group B). Hemodynamic assessment was performed at baseline and on the eighth day.
RESULTS: Spironolactone with propranolol caused a greater reduction in the hepatic venous pressure gradient than propranolol alone (26.94% vs 10.2%; P < 0.01). Fourteen out of eighteen patients on the combination treatment had a reduction in hepatic venous pressure gradient to ≤ 12 mmHg or a 20% reduction from baseline in contrast to only six out of seventeen (6/17) on propranolol alone (P < 0.05).
CONCLUSION: Spironolactone with propranolol results in a better response with a greater reduction in hepatic venous pressure gradient in the secondary prophylaxis of variceal bleeding. A greater number of patients may be protected by this combination therapy than by propranolol alone. Hence, this combination may be recommended for secondary prophylaxis in patients with variceal bleeding.
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Hillebrand U, Hausberg M, Lang D, Stock C, Riethmüller C, Callies C, Büssemaker E. How steroid hormones act on the endothelium—insights by atomic force microscopy. Pflugers Arch 2008; 456:51-60. [DOI: 10.1007/s00424-007-0411-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 11/20/2007] [Indexed: 02/05/2023]
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George J, Struthers AD. Evaluation of the aldosterone-blocking agent eplerenone in hypertension and heart failure. Expert Opin Pharmacother 2007; 8:3053-9. [PMID: 18001264 DOI: 10.1517/14656566.8.17.3053] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Aldosterone blockade is now seen as a crucial therapeutic strategy in the management of cardiovascular disease progression. There is increasing evidence that blocking the rennin-angiotensin-aldosterone system results in a reduction in overall cardiovascular risk. For 40 years, the only agent in this class was spironolactone. Despite its efficacy, the sexual side effects of spironolactone have resulted in poor compliance at best and discontinuation of therapy at worst. A newer agent, eplerenone, has been recently licensed for the treatment of heart failure and in the US also for hypertension. This article reviews the pathophysiology of aldosterone and critically reviews the present evidence for the efficacy and potential role for the new selective aldosterone-receptor antagonist, eplerenone.
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Affiliation(s)
- Jacob George
- Ninewells Hospital, Department of Clinical Pharmacology, Level 7, Dundee DD1 9SY, Scotland, UK.
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Ludwig T, Kirmse R, Poole K, Schwarz US. Probing cellular microenvironments and tissue remodeling by atomic force microscopy. Pflugers Arch 2007; 456:29-49. [PMID: 18058123 DOI: 10.1007/s00424-007-0398-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Revised: 11/06/2007] [Accepted: 11/09/2007] [Indexed: 12/20/2022]
Abstract
The function of cells is strongly determined by the properties of their extracellular microenvironment. Biophysical parameters like environmental stiffness and fiber orientation in the surrounding matrix are important determinants of cell adhesion and migration. Processes like tissue maintenance, wound repair, cancer cell invasion, and morphogenesis depend critically on the ability of cells to actively sense and remodel their surroundings. Pericellular proteolytic activity and adaptation of migration tactics to the environment are strategies to achieve this aim. Little is known about the distinct regulatory mechanisms that are involved in these processes. The system's critical biophysical and biochemical determinants are well accessible by atomic force microscopy (AFM), a unique tool for functional, nanoscale probing and morphometric, high-resolution imaging of processes in live cells. This review highlights common principles of tissue remodeling and focuses on application examples of different AFM techniques, for example elasticity mapping, the combination of AFM and fluorescence microscopy, the morphometric imaging of proteolytic activity, and force spectroscopy applications of single molecules or individual cells. To achieve a more complete understanding of the processes underlying the interaction of cells with their environments, the combination of AFM force spectroscopy experiments will be essential.
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Affiliation(s)
- Thomas Ludwig
- Group Microenvironment of Tumor Cell Invasion, German Cancer Research Center, BIOQUANT-Zentrum; BQ 0009 NWG Ludwig, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany.
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Di Fabio F, Alvarado C, Majdan A, Gologan A, Voda L, Mitmaker E, Beitel LK, Gordon PH, Trifiro M. Underexpression of mineralocorticoid receptor in colorectal carcinomas and association with VEGFR-2 overexpression. J Gastrointest Surg 2007; 11:1521-8. [PMID: 17703341 DOI: 10.1007/s11605-007-0234-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 06/30/2007] [Indexed: 01/31/2023]
Abstract
BACKGROUND The human mineralocorticoid receptor (MR) is a steroid receptor widely expressed in colorectal mucosa. A significant role for the MR in the reduction of vascular endothelial growth factor receptor-2 (VEGFR-2) mRNA levels has been demonstrated in vitro. To evaluate a potential contribution of MR to colorectal carcinoma progression, we analyzed the expression of MR in relation to VEGFR-2. METHODS Fresh human colorectal cancer tissue and adjacent normal mucosa were harvested from 48 consecutive patients. MR and VEGFR-2 mRNA expression levels were determined by real-time reverse transcriptase-polymerase chain reaction and correlated with clinicopathological parameters. RESULTS A decline of MR expression was observed in all carcinomas compared to normal mucosa. Expression of MR was a median of 11-fold lower in carcinoma compared to the normal mucosa, irrespective of the location, size, stage, and differentiation. MR was a median of 20-fold underexpressed in carcinomas with VEGFR-2 overexpression vs only 9-fold in carcinomas with VEGFR-2 underexpression (p = 0.035, Mann-Whitney test). CONCLUSIONS These findings support the hypothesis that reduction of MR expression may be one of the early events involved in colorectal carcinoma progression. The inverse association between MR and VEGFR-2 expression in carcinoma suggests a potential tumor-suppressive function for MR.
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Affiliation(s)
- Francesco Di Fabio
- Department of Colon and Rectal Surgery, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada.
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Oberleithner H, Riethmüller C, Schillers H, MacGregor GA, de Wardener HE, Hausberg M. Plasma sodium stiffens vascular endothelium and reduces nitric oxide release. Proc Natl Acad Sci U S A 2007; 104:16281-6. [PMID: 17911245 PMCID: PMC1999397 DOI: 10.1073/pnas.0707791104] [Citation(s) in RCA: 338] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Dietary salt plays a major role in the regulation of blood pressure, and the mineralocorticoid hormone aldosterone controls salt homeostasis and extracellular volume. Recent observations suggest that a small increase in plasma sodium concentration may contribute to the pressor response of dietary salt. Because endothelial cells are (i) sensitive to aldosterone, (ii) in physical contact with plasma sodium, and (iii) crucial regulators of vascular tone, we tested whether acute changes in plasma sodium concentration, within the physiological range, can alter the physical properties of endothelial cells. The tip of an atomic force microscope was used as a nanosensor to measure stiffness of living endothelial cells incubated for 3 days in a culture medium containing aldosterone at a physiological concentration (0.45 nM). Endothelial cell stiffness was unaffected by acute changes in sodium concentration <135 mM but rose steeply between 135 and 145 mM. The increase in stiffness occurred within minutes. Lack of aldosterone in the culture medium or treatment with the epithelial sodium channel inhibitor amiloride prevented this response. Nitric oxide formation was found down-regulated in cells cultured in aldosterone-containing high sodium medium. The results suggest that changes in plasma sodium concentration per se may affect endothelial function and thus control vascular tone.
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Affiliation(s)
- Hans Oberleithner
- Institute of Physiology II and Department of Internal Medicine D, University of Münster, 48149 Münster, Germany.
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Oberleithner H. Is the vascular endothelium under the control of aldosterone? Facts and hypothesis. Pflugers Arch 2007; 454:187-93. [PMID: 17285301 DOI: 10.1007/s00424-007-0205-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Accepted: 12/28/2006] [Indexed: 11/28/2022]
Abstract
Fluid and electrolyte balance in the human organism is controlled by aldosterone, a mineralocorticoid hormone of the suprarenal glands. The major target cells are localized in the kidney where the hormone controls transepithelial salt transport. Over the past few years, evidence has been accumulated that cells of the cardiovascular system are also targeted by the hormone. As an example, endothelial cells resemble similar mechanisms triggered by aldosterone as shown for the kidney. Although the pathological alterations induced by aldosterone excess are obvious, the physiological changes are largely unknown. On the basis of recent experiments, using atomic force microscopy as an imaging tool and a mechanical sensor, I present a hypothesis on the physiological role of aldosterone in endothelial function and its potential implications in the control of blood pressure.
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Affiliation(s)
- Hans Oberleithner
- Institut für Physiologie II, University of Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany.
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