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Tejwani V, Fawzy A, Putcha N, Castaldi P, Cho MH, Pratte KA, Bhatt SP, Lynch DA, Humphries SM, Kinney GL, D'Alessio FR, Hansel NN. Emphysema Progression and Lung Function Decline Among Angiotensin Converting Enzyme Inhibitors and Angiotensin-Receptor Blockade Users in the COPDGene Cohort. Chest 2021; 160:1245-1254. [PMID: 34029566 DOI: 10.1016/j.chest.2021.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Attenuation of transforming growth factor β by blocking angiotensin II has been shown to reduce emphysema in a murine model. General population studies have demonstrated that the use of angiotensin converting enzyme inhibitors (ACEis) and angiotensin-receptor blockers (ARBs) is associated with reduction of emphysema progression in former smokers and that the use of ACEis is associated with reduction of FEV1 progression in current smokers. RESEARCH QUESTION Is use of ACEi and ARB associated with less progression of emphysema and FEV1 decline among individuals with COPD or baseline emphysema? METHODS Former and current smokers from the Genetic Epidemiology of COPD Study who attended baseline and 5-year follow-up visits, did not change smoking status, and underwent chest CT imaging were included. Adjusted linear mixed models were used to evaluate progression of adjusted lung density (ALD), percent emphysema (%total lung volume <-950 Hounsfield units [HU]), 15th percentile of the attenuation histogram (attenuation [in HU] below which 15% of voxels are situated plus 1,000 HU), and lung function decline over 5 years between ACEi and ARB users and nonusers in those with spirometry-confirmed COPD, as well as all participants and those with baseline emphysema. Effect modification by smoking status also was investigated. RESULTS Over 5 years of follow-up, compared with nonusers, ACEi and ARB users with COPD showed slower ALD progression (adjusted mean difference [aMD], 1.6; 95% CI, 0.34-2.9). Slowed lung function decline was not observed based on phase 1 medication (aMD of FEV1 % predicted, 0.83; 95% CI, -0.62 to 2.3), but was when analysis was limited to consistent ACEi and ARB users (aMD of FEV1 % predicted, 1.9; 95% CI, 0.14-3.6). No effect modification by smoking status was found for radiographic outcomes, and the lung function effect was more pronounced in former smokers. Results were similar among participants with baseline emphysema. INTERPRETATION Among participants with spirometry-confirmed COPD or baseline emphysema, ACEi and ARB use was associated with slower progression of emphysema and lung function decline. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.
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Affiliation(s)
- Vickram Tejwani
- Division of Pulmonary and Critical Care, Johns Hopkins University, Baltimore, MD.
| | - Ashraf Fawzy
- Division of Pulmonary and Critical Care, Johns Hopkins University, Baltimore, MD
| | - Nirupama Putcha
- Division of Pulmonary and Critical Care, Johns Hopkins University, Baltimore, MD
| | | | - Michael H Cho
- Division of Pulmonary and Critical Care Medicine, Boston, MA; Harvard Medical School, Boston, MA
| | | | - Surya P Bhatt
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - David A Lynch
- Department of Radiology, National Jewish Health, Denver, CO
| | | | - Gregory L Kinney
- Department of Epidemiology, Colorado School of Public Health, Aurora, CO
| | - Franco R D'Alessio
- Division of Pulmonary and Critical Care, Johns Hopkins University, Baltimore, MD
| | - Nadia N Hansel
- Division of Pulmonary and Critical Care, Johns Hopkins University, Baltimore, MD
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Saavedra JM. Angiotensin Receptor Blockers Are Not Just for Hypertension Anymore. Physiology (Bethesda) 2021; 36:160-173. [PMID: 33904788 DOI: 10.1152/physiol.00036.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Beyond blood pressure control, angiotensin receptor blockers reduce common injury mechanisms, decreasing excessive inflammation and protecting endothelial and mitochondrial function, insulin sensitivity, the coagulation cascade, immune responses, cerebrovascular flow, and cognition, properties useful to treat inflammatory, age-related, neurodegenerative, and metabolic disorders of many organs including brain and lung.
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Affiliation(s)
- Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia
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Wang T, Gao L, Yang Z, Wang F, Guo Y, Wang B, Hua R, Shang H, Xu J. Restraint Stress in Hypertensive Rats Activates the Intestinal Macrophages and Reduces Intestinal Barrier Accompanied by Intestinal Flora Dysbiosis. J Inflamm Res 2021; 14:1085-1110. [PMID: 33790622 PMCID: PMC8007621 DOI: 10.2147/jir.s294630] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/22/2021] [Indexed: 12/14/2022] Open
Abstract
Purpose Hypertension (HTN) is a major risk factor for cardiovascular disease. In recent years, there were numerous studies on the function of stress in HTN. However, the gut dysbiosis linked to hypertension in animal models under stress is still incompletely understood. Purpose of this study is to use multiple determination method to determine the juvenile stage intestinal bacteria, cytokines and changes in hormone levels. Methods Four groups of juvenile male spontaneously hypertensive rats (SHRs) and age-matched male Wistar-Kyoto (WKY) rats were randomly selected as control and experimental groups. Rats in the two stress groups were exposed to restraint stress for 3 hours per day for 7 consecutive days. In one day three times in the method of non-invasive type tail-cuff monitoring blood pressure. The detailed mechanism was illuminated based on the intestinal change using immunohistochemical and immunofluorescence staining and the stress-related hormone and inflammation factors were analyzed via ELISA method. The integrity of the epithelial barrier was assessed using FITC/HRP and the expression levels of proteins associated with the tight junction was detected by Western blot. The alteration of stress-related intestinal flora from ileocecal junction and distal colon were also analyzed using its 16S rDNA sequencing. Results The results indicate that acute stress rapidly increases mean arterial pressure which is positive correlation to hormone concentration, especially in SHR-stress group. Meanwhile, stress promoted the enhancement of epithelial permeability accompanied with a reduced expression of the tight junction-related protein and the macrophages (Mφ) aggregation to the lamina propria. There were remarkable significant increase of stress-related hormones and pro-inflammatory factor interleukin (IL)-6 along with a decrease in the diversity of intestinal flora and an imbalance in the F/B ratio. Conclusion Our results reveal that stress accompanied with HTN could significantly disrupt the domino effect between intestinal flora and homeostasis.
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Affiliation(s)
- Tiantian Wang
- Department of Physiology and Pathophysiology, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Lei Gao
- Department of Biomedical Informatics, School of Biomedical Engineering, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Zejun Yang
- Department of Clinical Medicine, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Feifei Wang
- Department of Clinical Medicine, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Yuexin Guo
- Department of Oral Medicine, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Boya Wang
- Eight Program of Clinical Medicine, Peking University Health Science Center, Beijing, 100081, People's Republic of China
| | - Rongxuan Hua
- Department of Clinical Medicine, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Hongwei Shang
- Experimental Center for Morphological Research Platform, Capital Medical University, Beijing, 100069, People's Republic of China
| | - Jingdong Xu
- Department of Physiology and Pathophysiology, Basic Medical College, Capital Medical University, Beijing, 100069, People's Republic of China
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Elkahloun AG, Saavedra JM. Candesartan could ameliorate the COVID-19 cytokine storm. Biomed Pharmacother 2020; 131:110653. [PMID: 32942152 PMCID: PMC7439834 DOI: 10.1016/j.biopha.2020.110653] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Angiotensin receptor blockers (ARBs) reducing inflammation and protecting lung and brain function, could be of therapeutic efficacy in COVID-19 patients. METHODS Using GSEA, we compared our previous transcriptome analysis of neurons injured by glutamate and treated with the ARB Candesartan (GSE67036) with transcriptional signatures from SARS-CoV-2 infected primary human bronchial epithelial cells (NHBE) and lung postmortem (GSE147507), PBMC and BALF samples (CRA002390) from COVID-19 patients. RESULTS Hundreds of genes upregulated in SARS-CoV-2/COVID-19 transcriptomes were similarly upregulated by glutamate and normalized by Candesartan. Gene Ontology analysis revealed expression profiles with greatest significance and enrichment, including proinflammatory cytokine and chemokine activity, the NF-kappa B complex, alterations in innate and adaptive immunity, with many genes participating in the COVID-19 cytokine storm. CONCLUSIONS There are similar injury mechanisms in SARS-CoV-2 infection and neuronal injury, equally reduced by ARB treatment. This supports the hypothesis of a therapeutic role for ARBs, ameliorating the COVID-19 cytokine storm.
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Affiliation(s)
- Abdel G Elkahloun
- Comparative Genomics and Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, SE402 Med/Dent, 3900 Reservoir Road, Washington, DC 20057, USA.
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Darrah RJ, Jacono FJ, Joshi N, Mitchell AL, Sattar A, Campanaro CK, Litman P, Frey J, Nethery DE, Barbato ES, Hodges CA, Corvol H, Cutting GR, Knowles MR, Strug LJ, Drumm ML. AGTR2 absence or antagonism prevents cystic fibrosis pulmonary manifestations. J Cyst Fibros 2018; 18:127-134. [PMID: 29937318 DOI: 10.1016/j.jcf.2018.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/01/2018] [Accepted: 05/23/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND Pulmonary disease remains the primary cause of morbidity and mortality for individuals with cystic fibrosis (CF). Variants at a locus on the X-chromosome containing the type 2 angiotensin II receptor gene (AGTR2) were identified by a large GWAS as significantly associating with lung function in CF patients. We hypothesized that manipulating the angiotensin-signaling pathway may yield clinical benefit in CF. METHODS Genetic subset analysis was conducted on a local CF cohort to extend the GWAS findings. Next, we evaluated pulmonary function in CF mice with a deleted AGTR2 gene, and in those who were given subcutaneous injections of PD123,319, a selective AGTR2 antagonist for 12 weeks beginning at weaning. RESULTS The genetic subset analysis replicated the initial GWAS identified association, and confirmed the association of this locus with additional lung function parameters. Studies in genetically modified mice established that absence of the AGTR2 gene normalized pulmonary function indices in two independent CF mouse models. Further, we determined that pharmacologic antagonism of AGTR2 improved overall pulmonary function in CF mice to near wild-type levels. CONCLUSIONS These results identify that reduced AGTR2 signaling is beneficial to CF lung function, and suggest the potential of manipulating the angiotensin-signaling pathway for treatment and/or prevention of CF pulmonary disease. Importantly, the beneficial effects were not CF gene mutation dependent, and were able to be reproduced with pharmacologic antagonism. As there are clinically approved drugs available to target the renin-angiotensin signaling system, these findings may be quickly translated to human clinical trials.
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Affiliation(s)
- Rebecca J Darrah
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Frank J Jacono
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Medicine, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA
| | - Neha Joshi
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Anna L Mitchell
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Abdus Sattar
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Cara K Campanaro
- Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Paul Litman
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jennifer Frey
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
| | - David E Nethery
- Department of Medicine, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA
| | - Eric S Barbato
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Craig A Hodges
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Harriet Corvol
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre de Recherche Saint-Antoine (CRSA), Paris 75012, France; Pneumologie pédiatrique, APHP, Hôpital Trousseau, Paris 75012, France
| | - Garry R Cutting
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Michael R Knowles
- Marsico Lung Institute/UNC CF Research Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North, Carolina, 27599, USA
| | - Lisa J Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4; Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada M5T 3M7
| | - Mitchell L Drumm
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA
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Angiotensin-Converting Inhibitors and Angiotensin II Receptor Blockers and Longitudinal Change in Percent Emphysema on Computed Tomography. The Multi-Ethnic Study of Atherosclerosis Lung Study. Ann Am Thorac Soc 2018; 14:649-658. [PMID: 28207279 DOI: 10.1513/annalsats.201604-317oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
RATIONALE Although emphysema on computed tomography (CT) is associated with increased morbidity and mortality in patients with and without spirometrically defined chronic obstructive pulmonary disease, no available medications target emphysema outside of alpha-1 antitrypsin deficiency. Transforming growth factor-β and endothelial dysfunction are implicated in emphysema pathogenesis, and angiotensin II receptor blockers (ARBs) inhibit transforming growth factor-β, improve endothelial function, and restore airspace architecture in murine models. Evidence in humans is, however, lacking. OBJECTIVES To determine whether angiotensin-converting enzyme (ACE) inhibitor and ARB dose is associated with slowed progression of percent emphysema by CT. METHODS The Multi-Ethnic Study of Atherosclerosis researchers recruited participants ages 45-84 years from the general population from 2000 to 2002. Medication use was assessed by medication inventory. Percent emphysema was defined as the percentage of lung regions less than -950 Hounsfield units on CTs. Mixed-effects regression models were used to adjust for confounders. RESULTS Among 4,472 participants, 12% used an ACE inhibitor and 6% used an ARB at baseline. The median percent emphysema was 3.0% at baseline, and the rate of progression was 0.64 percentage points over a median of 9.3 years. Higher doses of ACE or ARB were independently associated with a slower change in percent emphysema (P = 0.03). Over 10 years, in contrast to a predicted mean increase in percent emphysema of 0.66 percentage points in those who did not take ARBs or ACE inhibitors, the predicted mean increase in participants who used maximum doses of ARBs or ACE inhibitors was 0.06 percentage points (P = 0.01). The findings were of greatest magnitude among former smokers (P < 0.001). Indications for ACE inhibitor or ARB drugs (hypertension and diabetes) and other medications for hypertension and diabetes were not associated independently with change in percent emphysema. There was no evidence that ACE inhibitor or ARB dose was associated with decline in lung function. CONCLUSIONS In a large population-based study, ACE inhibitors and ARBs were associated with slowed progression of percent emphysema by chest CT, particularly among former smokers. Randomized clinical trials of ACE and ARB agents are warranted for the prevention and treatment of emphysema.
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Saavedra JM, Armando I. Angiotensin II AT2 Receptors Contribute to Regulate the Sympathoadrenal and Hormonal Reaction to Stress Stimuli. Cell Mol Neurobiol 2018; 38:85-108. [PMID: 28884431 PMCID: PMC6668356 DOI: 10.1007/s10571-017-0533-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/01/2017] [Indexed: 12/14/2022]
Abstract
Angiotensin II, through AT1 receptor stimulation, mediates multiple cardiovascular, metabolic, and behavioral functions including the response to stressors. Conversely, the function of Angiotensin II AT2 receptors has not been totally clarified. In adult rodents, AT2 receptor distribution is very limited but it is particularly high in the adrenal medulla. Recent results strongly indicate that AT2 receptors contribute to the regulation of the response to stress stimuli. This occurs in association with AT1 receptors, both receptor types reciprocally influencing their expression and therefore their function. AT2 receptors appear to influence the response to many types of stressors and in all components of the hypothalamic-pituitary-adrenal axis. The molecular mechanisms involved in AT2 receptor activation, the complex interactions with AT1 receptors, and additional factors participating in the control of AT2 receptor regulation and activity in response to stressors are only partially understood. Further research is necessary to close this knowledge gap and to clarify whether AT2 receptor activation may carry the potential of a major translational advance.
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Affiliation(s)
- J M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, 3900 Reservoir Road, Bldg. D, Room 287, Washington, DC, 20007, USA.
| | - I Armando
- The George Washington University School of Medicine and Health Sciences, Ross Hall Suite 738 2300 Eye Street, Washington, DC, USA
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Silva-Filho JL, Souza MC, Henriques MG, Morrot A, Savino W, Caruso-Neves C, Pinheiro AAS. Renin-angiotensin system contributes to naive T-cell migration in vivo. Arch Biochem Biophys 2015; 573:1-13. [PMID: 25752953 DOI: 10.1016/j.abb.2015.02.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 02/04/2015] [Accepted: 02/28/2015] [Indexed: 01/11/2023]
Abstract
Angiotensin II (Ang II) plays an important role in the regulation of the T-cell response during inflammation. However, the cellular mechanisms underlying the regulation of lymphocytes under physiologic conditions have not yet been studied. Here, we tested the influence of Ang II on T-cell migration using T cells from BALB/c mice. The results obtained in vivo showed that when Ang II production or the AT1 receptor were blocked, T-cell counts were enhanced in blood but decreased in the spleen. The significance of these effects was confirmed by observing that these cells migrate, through fibronectin to Ang II via the AT1 receptor. We also observed a gradient of Ang II from peripheral blood to the spleen, which explains its chemotactic effect on this organ. The following cellular mechanisms were identified to mediate the Ang II effect: upregulation of the chemokine receptor CCR9; upregulation of the adhesion molecule CD62L; increased production of the chemokines CCL19 and CCL25 in the spleen. These results indicate that the higher levels of Ang II in the spleen and AT1 receptor activation contribute to migration of naive T cells to the spleen, which expands our understanding on how the Ang II/AT1 receptor axis contributes to adaptive immunity.
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Affiliation(s)
- J L Silva-Filho
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - M C Souza
- Instituto de Tecnologia em Fármacos, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - M G Henriques
- Instituto de Tecnologia em Fármacos, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - A Morrot
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - W Savino
- Departamento de Imunologia, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - C Caruso-Neves
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Biologia e Bioimagem, Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCT, Brazil
| | - A A S Pinheiro
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica, Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCT, Brazil.
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Hafko R, Villapol S, Nostramo R, Symes A, Sabban EL, Inagami T, Saavedra JM. Commercially available angiotensin II At₂ receptor antibodies are nonspecific. PLoS One 2013; 8:e69234. [PMID: 23840911 PMCID: PMC3698141 DOI: 10.1371/journal.pone.0069234] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/06/2013] [Indexed: 12/31/2022] Open
Abstract
Commercially available angiotensin II At₂ receptor antibodies are widely employed for receptor localization and quantification, but they have not been adequately validated. In this study, we characterized three commercially available At₂ receptor antibodies: 2818-1 from Epitomics, sc-9040 from Santa Cruz Biotechnology, Inc., and AAR-012 from Alomone Labs. Using western blot analysis the immunostaining patterns observed were different for every antibody tested, and in most cases consisted of multiple immunoreactive bands. Identical immunoreactive patterns were present in wild-type and At₂ receptor knockout mice not expressing the target protein. In the mouse brain, immunocytochemical studies revealed very different cellular immunoreactivity for each antibody tested. While the 2818-1 antibody reacted only with endothelial cells in small parenchymal arteries, the sc-9040 antibody reacted only with ependymal cells lining the cerebral ventricles, and the AAR-012 antibody reacted only with multiple neuronal cell bodies in the cerebral cortex. Moreover, the immunoreactivities were identical in brain tissue from wild-type or At₂ receptor knockout mice. Furthermore, in both mice and rat tissue extracts, there was no correlation between the observed immunoreactivity and the presence or absence of At₂ receptor binding or gene expression. We conclude that none of these commercially available At₂ receptor antibodies tested met the criteria for specificity. In the absence of full antibody characterization, competitive radioligand binding and determination of mRNA expression remain the only reliable approaches to study At₂ receptor expression.
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Affiliation(s)
- Roman Hafko
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sonia Villapol
- Centre for Neuroscience and Regenerative Medicine, Bethesda, Maryland, United States of America
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Regina Nostramo
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Aviva Symes
- Centre for Neuroscience and Regenerative Medicine, Bethesda, Maryland, United States of America
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Esther L. Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Tadashi Inagami
- Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Juan M. Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Angiotensin II AT(2) receptor decreases AT(1) receptor expression and function via nitric oxide/cGMP/Sp1 in renal proximal tubule cells from Wistar-Kyoto rats. J Hypertens 2012; 30:1176-84. [PMID: 22504846 DOI: 10.1097/hjh.0b013e3283532099] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND The renin-angiotensin (Ang) system controls blood pressure, in part, by regulating renal tubular sodium transport. In the kidney, activation of the angiotensin II type 1 (AT(1)) receptor increases renal sodium reabsorption, whereas the angiotensin II type 2 (AT(2)) receptor produces the opposite effect. We hypothesized that the AT(2) receptor regulates AT(1) receptor expression and function in the kidney. METHODS AND RESULTS In immortalized renal proximal tubule (RPT) cells from Wistar-Kyoto rats, CGP42112, an AT(2) receptor agonist, decreased AT(1) receptor mRNA and protein expression (P < 0.05), as assessed by reverse transcriptase-polymerase chain reaction and immunoblotting. The inhibitory effect of the AT(2) receptor on AT(1) receptor expression was blocked by the AT(2) receptor antagonist, PD123319 (10 (-6)mol/l), the nitric oxide synthase inhibitor N(w)-nitro-L-arginine methyl ester (10(-4) mol/l), or the nitric oxide-dependent soluble guanylate cyclase inhibitor 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (10(-5) mol/l), indicating that both nitric oxide and cyclic guanosine monophosphate (cGMP) were involved in the signaling pathway. Furthermore, CGP42112 decreased Sp1 serine phosphorylation and reduced the binding of Sp1 to AT(1) receptor DNA. Stimulation with Ang II (10(-11) mol/l per 30 min) enhanced Na(+)-K(+)-ATPase activity in RPT cells, which was prevented by pretreatment with CGP42112 (10(-7) mol/l per 24 h) (P < 0.05). The above-mentioned results were confirmed in RPT cells from AT(2) receptor knockout mice; AT(1) receptor expression and Ang II-stimulated Na-K-ATPase activity were greater in these cells than in RPT cells from wild-type mice (P < 0.05). AT(1)/AT(2) receptors co-localized and co-immunoprecipitated in RPT cells; short-term CGP42112 (10 mol/l per 30 min) treatment increased AT(1)/AT(2) receptor co-immunoprecipitation (P < 0.05). CONCLUSIONS These results indicate that the renal AT(2) receptor, via nitric oxide/cGMP/Sp1 pathway, regulates AT(1 )receptor expression and function, which may be important in the regulation of sodium excretion and blood pressure.
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Gao J, Chao J, Parbhu KJK, Yu L, Xiao L, Gao F, Gao L. Ontogeny of angiotensin type 2 and type 1 receptor expression in mice. J Renin Angiotensin Aldosterone Syst 2012; 13:341-52. [PMID: 22526820 DOI: 10.1177/1470320312443720] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In the current experiment, we determined angiotensin type 2 receptor (AT2R) and angiotensin type 1 receptor (AT1R) protein expression by western blot analysis in developing normal mice. The results indicate that: (1) in all detected brain regions and in the spinal cord, adult mice exhibited significantly higher AT2R expression and lower AT1R expression in total protein extracts compared to fetuses and neonates; (2) other major organs, including heart, lung, liver and kidney, exhibited the same expression pattern as the brain and spinal cord; (3) reciprocal changes in AT2R and AT1R expression were found in the total protein extracts from the brainstems of mice from one-day prenatal to six weeks of age, and there was a negative correlation between AT2R and AT1R protein expression; (4) in both membrane and cytosolic fractions from the brainstem, adult mice exhibited higher AT2R and lower AT1R expression than did fetuses and neonates; and (5) in the brainstem, there were no significant differences in AT2R and AT1R messenger RNA (mRNA) levels among fetal, neonatal and adult mice. The above results reconfirmed our previous finding in rats that adult animals have higher AT2R and lower AT1R expression compared to fetuses and neonates. These data imply an involvement of AT1R in fetal development and of AT2R in adult function.
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Affiliation(s)
- Juan Gao
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, USA
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Podowski M, Calvi C, Metzger S, Misono K, Poonyagariyagorn H, Lopez-Mercado A, Ku T, Lauer T, McGrath-Morrow S, Berger A, Cheadle C, Tuder R, Dietz HC, Mitzner W, Wise R, Neptune E. Angiotensin receptor blockade attenuates cigarette smoke-induced lung injury and rescues lung architecture in mice. J Clin Invest 2011; 122:229-40. [PMID: 22182843 DOI: 10.1172/jci46215] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 11/09/2011] [Indexed: 01/24/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a prevalent smoking-related disease for which no disease-altering therapies currently exist. As dysregulated TGF-β signaling associates with lung pathology in patients with COPD and in animal models of lung injury induced by chronic exposure to cigarette smoke (CS), we postulated that inhibiting TGF-β signaling would protect against CS-induced lung injury. We first confirmed that TGF-β signaling was induced in the lungs of mice chronically exposed to CS as well as in COPD patient samples. Importantly, key pathological features of smoking-associated lung disease in patients, e.g., alveolar injury with overt emphysema and airway epithelial hyperplasia with fibrosis, accompanied CS-induced alveolar cell apoptosis caused by enhanced TGF-β signaling in CS-exposed mice. Systemic administration of a TGF-β-specific neutralizing antibody normalized TGF-β signaling and alveolar cell death, conferring improved lung architecture and lung mechanics in CS-exposed mice. Use of losartan, an angiotensin receptor type 1 blocker used widely in the clinic and known to antagonize TGF-β signaling, also improved oxidative stress, inflammation, metalloprotease activation and elastin remodeling. These data support our hypothesis that inhibition of TGF-β signaling through angiotensin receptor blockade can attenuate CS-induced lung injury in an established murine model. More importantly, our findings provide a preclinical platform for the development of other TGF-β-targeted therapies for patients with COPD.
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Affiliation(s)
- Megan Podowski
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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