1
|
Silva PA, Monnerat-Cahli G, Pereira-Acácio A, Luzardo R, Sampaio LS, Luna-Leite MA, Lara LS, Einicker-Lamas M, Panizzutti R, Madeira C, Vieira-Filho LD, Castro-Chaves C, Ribeiro VS, Paixão ADO, Medei E, Vieyra A. Mechanisms involving Ang II and MAPK/ERK1/2 signaling pathways underlie cardiac and renal alterations during chronic undernutrition. PLoS One 2014; 9:e100410. [PMID: 24983243 PMCID: PMC4077653 DOI: 10.1371/journal.pone.0100410] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 05/27/2014] [Indexed: 02/07/2023] Open
Abstract
Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood.
Collapse
Affiliation(s)
- Paulo A. Silva
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Gustavo Monnerat-Cahli
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Amaury Pereira-Acácio
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Ricardo Luzardo
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Luzia S. Sampaio
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Marcia A. Luna-Leite
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucienne S. Lara
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo Einicker-Lamas
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Rogério Panizzutti
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caroline Madeira
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leucio D. Vieira-Filho
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Carmen Castro-Chaves
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Valdilene S. Ribeiro
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Ana D. O. Paixão
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Brazil
| | - Emiliano Medei
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Structural Biology and Bioimaging, Rio de Janeiro, Brazil
- * E-mail:
| |
Collapse
|
2
|
Rocafull MA, Thomas LE, del Castillo JR. The second sodium pump: from the function to the gene. Pflugers Arch 2012; 463:755-77. [PMID: 22543357 PMCID: PMC3350626 DOI: 10.1007/s00424-012-1101-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 03/22/2012] [Accepted: 03/24/2012] [Indexed: 11/30/2022]
Abstract
Transepithelial Na(+) transport is mediated by passive Na(+) entry across the luminal membrane and exit through the basolateral membrane by two active mechanisms: the Na(+)/K(+) pump and the second sodium pump. These processes are associated with the ouabain-sensitive Na(+)/K(+)-ATPase and the ouabain-insensitive, furosemide-inhibitable Na(+)-ATPase, respectively. Over the last 40 years, the second sodium pump has not been successfully associated with any particular membrane protein. Recently, however, purification and cloning of intestinal α-subunit of the Na(+)-ATPase from guinea pig allowed us to define it as a unique biochemical and molecular entity. The Na(+)- and Na(+)/K(+)-ATPase genes are at the same locus, atp1a1, but have independent promoters and some different exons. Herein, we spotlight the functional characteristics of the second sodium pump, and the associated Na(+)-ATPase, in the context of its role in transepithelial transport and its response to a variety of physiological and pathophysiological conditions. Identification of the Na(+)-ATPase gene (atna) allowed us, using a bioinformatics approach, to explore the tertiary structure of the protein in relation to other P-type ATPases and to predict regulatory sites in the promoter region. Potential regulatory sites linked to inflammation and cellular stress were identified in the atna gene. In addition, a human atna ortholog was recognized. Finally, experimental data obtained using spontaneously hypertensive rats suggest that the Na(+)-ATPase could play a role in the pathogenesis of essential hypertension. Thus, the participation of the second sodium pump in transepithelial Na(+) transport and cellular Na(+) homeostasis leads us to reconsider its role in health and disease.
Collapse
Affiliation(s)
- Miguel A. Rocafull
- Laboratorio de Fisiología Molecular, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Apartado 20632, Caracas, 1020A Venezuela
| | - Luz E. Thomas
- Laboratorio de Fisiología Molecular, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Apartado 20632, Caracas, 1020A Venezuela
| | - Jesús R. del Castillo
- Laboratorio de Fisiología Molecular, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Apartado 20632, Caracas, 1020A Venezuela
| |
Collapse
|