21 results on '"Burghi V"'
Search Results
2. Variation in Floral Morphology and Seed Production of Buffel and Rhodes Grass.
- Author
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Erazo, E. B., Rodriguez, J. E. Mojica, Aldana, G. A. Brochero, Salazar, J. R. Mejia, Kerguelen, S. L. Mejia, and Burghi, V. H.
- Subjects
FLORAL morphology ,SEED industry ,SEED yield ,GENETIC variation ,GERMPLASM ,BLOCK designs ,POLLINATION - Abstract
Copyright of Journal of Agricultural Science & Technology is the property of Tarbiat Modares University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
3. Validation of commercial Mas receptor antibodies for utilization in Western Blotting, immunofluorescence and immunohistochemistry studies
- Author
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Burghi, V., Fernández, N.C., Gándola, Y.B., Piazza, V.G., Quiroga, D.T., Guilhen Mario, E., Felix Braga, J., Bader, M., Santos, R.A.S., Dominici, F.P., and Munoz, M.C.
- Subjects
Cardiovascular and Metabolic Diseases - Abstract
Mas receptor (MasR) is a G protein-coupled receptor proposed as a candidate for mediating the angiotensin (Ang)-converting enzyme 2-Ang (1-7) protective axis of renin-angiotensin system. Because the role of this receptor is not definitively clarified, determination of MasR tissue distribution and expression levels constitutes a critical knowledge to fully understanding its function. Commercially available antibodies have been widely employed for MasR protein localization and quantification, but they have not been adequately validated. In this study, we carried on an exhaustive evaluation of four commercial MasR antibodies, following previously established criteria. Western Blotting (WB) and immunohistochemistry studies starting from hearts and kidneys from wild type (WT) mice revealed that antibodies raised against different MasR domains yielded different patterns of reactivity. Furthermore, staining patterns appeared identical in samples from MasR knockout (MasR-KO) mice. We verified by polymerase chain reaction analysis that the MasR-KO mice used were truly deficient in this receptor as MAS transcripts were undetectable in either heart or kidney from this animal model. In addition, we evaluated the ability of the antibodies to detect the human c-myc-tagged MasR overexpressed in human embryonic kidney cells. Three antibodies were capable of detecting the MasR either by WB or by immunofluorescence, reproducing the patterns obtained with an anti c-myc antibody. In conclusion, although three of the selected antibodies were able to detect MasR protein at high expression levels observed in a transfected cell line, they failed to detect this receptor in mice tissues at physiological expression levels. As a consequence, validated antibodies that can recognize and detect the MasR at physiological levels are still lacking.
- Published
- 2017
4. Influence of sward condition on leaf tissue turnover in tall fescue and tall wheatgrass swards under continuous grazing
- Author
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Agnusdei, M. G., primary, Assuero, S. G., additional, Fernández Grecco, R. C., additional, Cordero, J. J., additional, and Burghi, V. H., additional
- Published
- 2007
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5. YAP-driven malignant reprogramming of oral epithelial stem cells at single cell resolution.
- Author
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Faraji F, Ramirez SI, Clubb LM, Sato K, Burghi V, Hoang TS, Officer A, Anguiano Quiroz PY, Galloway WMG, Mikulski Z, Medetgul-Ernar K, Marangoni P, Jones KB, Cao Y, Molinolo AA, Kim K, Sakaguchi K, Califano JA 3rd, Smith Q, Goren A, Klein OD, Tamayo P, and Gutkind JS
- Subjects
- Humans, Animals, Mice, Transcription Factors metabolism, Transcription Factors genetics, Signal Transduction, Adaptor Proteins, Signal Transducing metabolism, Adaptor Proteins, Signal Transducing genetics, Epithelial-Mesenchymal Transition genetics, Head and Neck Neoplasms genetics, Head and Neck Neoplasms pathology, Head and Neck Neoplasms metabolism, Gene Expression Regulation, Neoplastic, Stem Cells metabolism, TOR Serine-Threonine Kinases metabolism, Cell Differentiation, Carcinogenesis genetics, Carcinogenesis pathology, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Single-Cell Analysis, Cellular Reprogramming genetics, Epithelial Cells metabolism, Epithelial Cells pathology, YAP-Signaling Proteins metabolism
- Abstract
Tumor initiation represents the first step in tumorigenesis during which normal progenitor cells undergo cell fate transition to cancer. Capturing this process as it occurs in vivo, however, remains elusive. Here we employ spatiotemporally controlled oncogene activation and tumor suppressor inhibition together with multiomics to unveil the processes underlying oral epithelial progenitor cell reprogramming into tumor initiating cells at single cell resolution. Tumor initiating cells displayed a distinct stem-like state, defined by aberrant proliferative, hypoxic, squamous differentiation, and partial epithelial to mesenchymal invasive gene programs. YAP-mediated tumor initiating cell programs included activation of oncogenic transcriptional networks and mTOR signaling, and recruitment of myeloid cells to the invasive front contributing to tumor infiltration. Tumor initiating cell transcriptional programs are conserved in human head and neck cancer and associated with poor patient survival. These findings illuminate processes underlying cancer initiation at single cell resolution, and identify candidate targets for early cancer detection and prevention., Competing Interests: Competing interests: J.S.G. has received other commercial research support from Kura Oncology, Mavupharma, Dracen, Verastem, and SpringWorks Therapeutics, and is a consultant/advisory board member for Domain Therapeutics, Pangea Therapeutics, and io9, and founder of Kadima Pharmaceuticals. The remaining authors declare no competing interests., (© 2025. The Author(s).)
- Published
- 2025
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6. YAP-Driven Oral Epithelial Stem Cell Malignant Reprogramming at Single Cell Resolution.
- Author
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Faraji F, Ramirez SI, Clubb L, Sato K, Burghi V, Hoang TS, Officer A, Anguiano Quiroz PY, Galloway WM, Mikulski Z, Medetgul-Ernar K, Marangoni P, Jones KB, Molinolo AA, Kim K, Sakaguchi K, Califano JA, Smith Q, Goren A, Klein OD, Tamayo P, and Gutkind JS
- Abstract
Tumor initiation represents the first step in tumorigenesis during which normal progenitor cells undergo cell fate transition to cancer. Capturing this process as it occurs in vivo, however, remains elusive. Here we employ spatiotemporally controlled oncogene activation and tumor suppressor inhibition together with multiomics to unveil the processes underlying oral epithelial progenitor cell reprogramming into tumor initiating cells (TIC) at single cell resolution. TIC displayed a distinct stem-like state, defined by aberrant proliferative, hypoxic, squamous differentiation, and partial epithelial to mesenchymal (pEMT) invasive gene programs. YAP-mediated TIC programs included the activation of oncogenic transcriptional networks and mTOR signaling, and the recruitment of myeloid cells to the invasive front contributing to tumor infiltration. TIC transcriptional programs are conserved in human head and neck cancer and associated with poor patient survival. These findings illuminate processes underlying cancer initiation at single cell resolution, and identify candidate targets for early cancer detection and prevention.
- Published
- 2024
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7. Gαs is dispensable for β-arrestin coupling but dictates GRK selectivity and is predominant for gene expression regulation by β2-adrenergic receptor.
- Author
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Burghi V, Paradis JS, Officer A, Adame-Garcia SR, Wu X, Matthees ESF, Barsi-Rhyne B, Ramms DJ, Clubb L, Acosta M, Tamayo P, Bouvier M, Inoue A, von Zastrow M, Hoffmann C, and Gutkind JS
- Subjects
- Humans, beta-Arrestin 1 genetics, beta-Arrestin 1 metabolism, beta-Arrestin 2 genetics, beta-Arrestin 2 metabolism, Cyclic AMP-Dependent Protein Kinases metabolism, Mitogen-Activated Protein Kinases metabolism, Phosphorylation, HEK293 Cells, GTP-Binding Protein alpha Subunits genetics, GTP-Binding Protein alpha Subunits metabolism, Protein Structure, Tertiary, Protein Isoforms, Enzyme Activation genetics, beta-Arrestins genetics, beta-Arrestins metabolism, Gene Expression Regulation genetics, GTP-Binding Proteins metabolism, Receptors, Adrenergic, beta-2 chemistry, Receptors, Adrenergic, beta-2 genetics, Receptors, Adrenergic, beta-2 metabolism
- Abstract
β-arrestins play a key role in G protein-coupled receptor (GPCR) internalization, trafficking, and signaling. Whether β-arrestins act independently of G protein-mediated signaling has not been fully elucidated. Studies using genome-editing approaches revealed that whereas G proteins are essential for mitogen-activated protein kinase activation by GPCRs., β-arrestins play a more prominent role in signal compartmentalization. However, in the absence of G proteins, GPCRs may not activate β-arrestins, thereby limiting the ability to distinguish G protein from β-arrestin-mediated signaling events. We used β2-adrenergic receptor (β2AR) and its β2AR-C tail mutant expressed in human embryonic kidney 293 cells wildtype or CRISPR-Cas9 gene edited for Gα
s , β-arrestin1/2, or GPCR kinases 2/3/5/6 in combination with arrestin conformational sensors to elucidate the interplay between Gαs and β-arrestins in controlling gene expression. We found that Gαs is not required for β2AR and β-arrestin conformational changes, β-arrestin recruitment, and receptor internalization, but that Gαs dictates the GPCR kinase isoforms involved in β-arrestin recruitment. By RNA-Seq analysis, we found that protein kinase A and mitogen-activated protein kinase gene signatures were activated by stimulation of β2AR in wildtype and β-arrestin1/2-KO cells but absent in Gαs -KO cells. These results were validated by re-expressing Gαs in the corresponding KO cells and silencing β-arrestins in wildtype cells. These findings were extended to cellular systems expressing endogenous levels of β2AR. Overall, our results support that Gs is essential for β2AR-promoted protein kinase A and mitogen-activated protein kinase gene expression signatures, whereas β-arrestins initiate signaling events modulating Gαs -driven nuclear transcriptional activity., Competing Interests: Conflict of interest J. S. G. is consultant for Domain Therapeutics, Pangea Therapeutics, and io9, and founder of Kadima Pharmaceuticals, outside the submitted work. M. B. is the president of Domain Therapeutics Scientific Advisory Board. The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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8. A reversible SRC-relayed COX2 inflammatory program drives resistance to BRAF and EGFR inhibition in BRAF V600E colorectal tumors.
- Author
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Ruiz-Saenz A, Atreya CE, Wang C, Pan B, Dreyer CA, Brunen D, Prahallad A, Muñoz DP, Ramms DJ, Burghi V, Spassov DS, Fewings E, Hwang YC, Cowdrey C, Moelders C, Schwarzer C, Wolf DM, Hann B, VandenBerg SR, Shokat K, Moasser MM, Bernards R, Gutkind JS, van 't Veer LJ, and Coppé JP
- Subjects
- Humans, Cyclooxygenase 2 genetics, Cyclooxygenase 2 therapeutic use, MAP Kinase Signaling System, ErbB Receptors genetics, src-Family Kinases genetics, src-Family Kinases therapeutic use, Proto-Oncogene Proteins B-raf genetics, Proto-Oncogene Proteins B-raf metabolism, Colorectal Neoplasms drug therapy, Colorectal Neoplasms genetics, Colorectal Neoplasms pathology
- Abstract
BRAF
V600E mutation confers a poor prognosis in metastatic colorectal cancer (CRC) despite combinatorial targeted therapies based on the latest understanding of signaling circuitry. To identify parallel resistance mechanisms induced by BRAF-MEK-EGFR co-targeting, we used a high-throughput kinase activity mapping platform. Here we show that SRC kinases are systematically activated in BRAFV600E CRC following targeted inhibition of BRAF ± EGFR and that coordinated targeting of SRC with BRAF ± EGFR increases treatment efficacy in vitro and in vivo. SRC drives resistance to BRAF ± EGFR targeted therapy independently of ERK signaling by inducing transcriptional reprogramming through β-catenin (CTNNB1). The EGFR-independent compensatory activation of SRC kinases is mediated by an autocrine prostaglandin E2 loop that can be blocked with cyclooxygenase-2 (COX2) inhibitors. Co-targeting of COX2 with BRAF + EGFR promotes durable suppression of tumor growth in patient-derived tumor xenograft models. COX2 inhibition represents a drug-repurposing strategy to overcome therapeutic resistance in BRAFV600E CRC., (© 2023. The Author(s).)- Published
- 2023
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9. Insulin signaling in the heart is impaired by growth hormone: a direct and early event.
- Author
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Muñoz MC, Piazza VG, Burghi V, Giani JF, Martinez CS, Cicconi NS, Muia NV, Fang Y, Lavandero S, Sotelo AI, Bartke A, Pennisi PA, Dominici FP, and Miquet JG
- Subjects
- Animals, Growth Hormone metabolism, Insulin metabolism, Insulin-Like Growth Factor I metabolism, Mice, Myocytes, Cardiac metabolism, Phosphatidylinositol 3-Kinases metabolism, Rats, Signal Transduction, Acromegaly, Human Growth Hormone
- Abstract
Growth hormone (GH) exerts major actions in cardiac growth and metabolism. Considering the important role of insulin in the heart and the well-established anti-insulin effects of GH, cardiac insulin resistance may play a role in the cardiopathology observed in acromegalic patients. As conditions of prolonged exposure to GH are associated with a concomitant increase of circulating GH, IGF1 and insulin levels, to dissect the direct effects of GH, in this study, we evaluated the activation of insulin signaling in the heart using four different models: (i) transgenic mice overexpressing GH, with chronically elevated GH, IGF1 and insulin circulating levels; (ii) liver IGF1-deficient mice, with chronically elevated GH and insulin but decreased IGF1 circulating levels; (iii) mice treated with GH for a short period of time; (iv) primary culture of rat cardiomyocytes incubated with GH. Despite the differences in the development of cardiomegaly and in the metabolic alterations among the three experimental mouse models analyzed, exposure to GH was consistently associated with a decreased response to acute insulin stimulation in the heart at the receptor level and through the PI3K/AKT pathway. Moreover, a blunted response to insulin stimulation of this signaling pathway was also observed in cultured cardiomyocytes of neonatal rats incubated with GH. Therefore, the key novel finding of this work is that impairment of insulin signaling in the heart is a direct and early event observed as a consequence of exposure to GH, which may play a major role in the development of cardiac pathology.
- Published
- 2022
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10. Biased agonism at histamine H 1 receptor: Desensitization, internalization and MAPK activation triggered by antihistamines.
- Author
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Burghi V, Echeverría EB, Zappia CD, Díaz Nebreda A, Ripoll S, Gómez N, Shayo C, Davio CA, Monczor F, and Fernández NC
- Subjects
- A549 Cells, Calcium Signaling drug effects, Cyclooxygenase 2 genetics, Cyclooxygenase 2 metabolism, Drug Inverse Agonism, Enzyme Activation, G-Protein-Coupled Receptor Kinase 2 genetics, G-Protein-Coupled Receptor Kinase 2 metabolism, GTP-Binding Protein alpha Subunits, Gq-G11 metabolism, Humans, Inflammation Mediators metabolism, Inositol 1,4,5-Trisphosphate metabolism, Interleukin-8 genetics, Interleukin-8 metabolism, Ligands, Phosphorylation, Protein Transport, Receptors, Histamine H1 metabolism, Type C Phospholipases metabolism, Extracellular Signal-Regulated MAP Kinases metabolism, Histamine Agonists pharmacology, Histamine H1 Antagonists pharmacology, Receptors, Histamine H1 drug effects
- Abstract
Histamine H
1 receptor ligands used clinically as antiallergics rank among the most widely prescribed and over-the-counter drugs in the world. They exert the therapeutic actions by blocking the effects of histamine, due to null or negative efficacy towards Gαq -phospholipase C (PLC)-inositol triphosphates (IP3 )-Ca2+ and nuclear factor-kappa B cascades. However, there is no information regarding their ability to modulate other receptor responses. The aim of the present study was to investigate whether histamine H1 receptor ligands could display positive efficacy concerning receptor desensitization, internalization, signaling through Gαq independent pathways or even transcriptional regulation of proinflammatory genes. While diphenhydramine, triprolidine and chlorpheniramine activate ERK1/2 (extracellular signal-regulated kinase 1/2) pathway in A549 cells, pre-treatment with chlorpheniramine or triprolidine completely desensitize histamine H1 receptor mediated Ca2+ response, and both diphenhydramine and triprolidine lead to receptor internalization. Unlike histamine, histamine H1 receptor desensitization and internalization induced by antihistamines prove to be independent of G protein-coupled receptor kinase 2 (GRK2) phosphorylation. Also, unlike the reference agonist, the recovery of the number of cell-surface histamine H1 receptors is a consequence of de novo synthesis. On the other hand, all of the ligands lack efficacy regarding cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) mRNA regulation. However, a prolonged exposure with each of the antihistamines impaires the increase in COX-2 and IL-8 mRNA levels induced by histamine, even after ligand removal. Altogether, these findings demonstrate the biased nature of histamine H1 receptor ligands contributing to a more accurate classification, and providing evidence for a more rational and safe use of them., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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11. The Regulator of G Protein Signaling Homologous Domain of G Protein-Coupled Receptor Kinase 2 Mediates Short-Term Desensitization of β3-Adrenergic Receptor.
- Author
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Echeverría E, Cabrera M, Burghi V, Sosa M, Ripoll S, Yaneff A, Monczor F, Davio C, Shayo C, and Fernández N
- Abstract
G protein coupled receptor (GPCR) kinases (GRKs) are key regulators of GPCR signaling. Canonical mechanism of GPCR desensitization involves receptor phosphorylation by GRKs followed by arrestin recruitment and uncoupling from heterotrimeric G protein. Although β3-adrenergic receptor (β3AR) lacks phosphorylation sites by GRKs, agonist treatment proved to induce β3AR desensitization in many cell types. Here we show that GRK2 mediates short-term desensitization of β3AR by a phosphorylation independent mechanism but mediated by its domain homologous to the regulator of G protein signaling (RGS). HEK293T cells overexpressing human β3AR presented a short-term desensitization of cAMP response stimulated by the β3AR agonist, BRL37344, and not by forskolin. We found that β3AR desensitization was higher in cells co-transfected with GRK2. Similarly, overexpression of the RGS homology domain but not kinase domain of GRK2 increased β3AR desensitization. Consistently, stimulation of β3AR increased interaction between GRK2 and Gαs subunit. Furthermore, in rat cardiomyocytes endogenously expressing β3AR, transfection with dominant negative mutant of RH domain of GRK2 (GRK2/D110A) increased cAMP response to BRL37344 and inhibited receptor desensitization. We expect our study to be a starting point for more sophisticated characterization of the consequences of GRK2 mediated desensitization of the β3AR in heart function and disease., (Copyright © 2020 Echeverría, Cabrera, Burghi, Sosa, Ripoll, Yaneff, Monczor, Davio, Shayo and Fernández.)
- Published
- 2020
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12. Identification of inhibitors of the RGS homology domain of GRK2 by docking-based virtual screening.
- Author
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Echeverría E, Velez Rueda AJ, Cabrera M, Juritz E, Burghi V, Fabián L, Davio C, Lorenzano Menna P, and Fernández NC
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- A549 Cells, Computer Simulation, Cyclic AMP-Dependent Protein Kinases metabolism, G-Protein-Coupled Receptor Kinase 2 chemistry, GTP-Binding Protein alpha Subunits, Gq-G11 metabolism, HeLa Cells, Humans, Mass Screening, Molecular Docking Simulation methods, Phosphorylation, Protein Binding, Protein Domains, Protein Kinase Inhibitors chemistry, Receptors, Histamine H1 metabolism, Signal Transduction, G-Protein-Coupled Receptor Kinase 2 antagonists & inhibitors, G-Protein-Coupled Receptor Kinase 2 metabolism, Protein Kinase Inhibitors pharmacology
- Abstract
Aims: G protein-coupled receptor (GPCR) kinases (GRKs) are mainly involved in the desensitization of GPCRs. Among them, GRK2 has been described to be upregulated in many pathological conditions and its crucial role in cardiac hypertrophy, hypertension, and heart failure promoted the search for pharmacological inhibitors of its activity. There have been several reports of potent and selective inhibitors of GRK2, most of them directed to the kinase domain of the protein. However, the homologous to the regulator of G protein signaling (RH) domain of GRK2 has also been shown to regulate GPCRs signaling. Herein, we searched for potential inhibitors of receptor desensitization mediated by RH domain of GRK2., Materials and Methods: We performed a docking-based virtual screening utilizing the crystal structure of GRK2 to search for potential inhibitors of the interaction between GRK2 and Gαq protein. To evaluate the biological activity of compounds we measured, calcium response of histamine H1 receptor (H1R) using Fura-2AM dye and H1R internalization by saturation binding experiments in A549 cells. GRK2(45-178)GFP translocation was determined in HeLa cells through confocal fluorescence imaging., Key Findings: We identified inhibitors of GRK2 able to reduce the RH mediated desensitization of the histamine H1 receptor and GRK2 translocation to plasma membrane. Also candidates presented adequate lipophilia and cytotoxicity profile., Significance: We obtained compounds with the ability of reducing RH mediated actions of GRK2 that can be useful as a starting point in the development of novel drug candidates aimed to treat pathologies were GRK2 plays a key role., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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13. Involvement of histamine H 1 and H 2 receptor inverse agonists in receptor's crossregulation.
- Author
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Díaz Nebreda A, Zappia CD, Rodríguez González A, Sahores A, Sosa M, Burghi V, Monczor F, Davio C, Fernández N, and Shayo C
- Subjects
- Cell Line, Cell Line, Tumor, HEK293 Cells, Histamine metabolism, Humans, Signal Transduction physiology, U937 Cells, Histamine Agonists metabolism, Histamine H1 Antagonists metabolism, Receptors, Histamine H1 metabolism, Receptors, Histamine H2 metabolism
- Abstract
Histamine [2-(4-Imidazolyl)-ethylamine] modulates different biological processes, through histamine H
1 and H2 receptors, and their respective blockers are widely used in treating allergic and gastric acid-related disorders. Histamine H1 and H2 receptor crossdesensitization and cointernalization induced by its agonists have been previously described. In this study, we show how this crosstalk determines the response to histamine H1 and H2 receptor inverse agonists and how histamine H1 and H2 receptor inverse agonists interfere with the other receptor's response to agonists. By desensitization assays we demonstrate that histamine H1 and H2 receptor inverse agonists induce a crossregulation between both receptors. In this sense, the histamine H1 receptor inverse agonists desensitize the cAMP response to amthamine, a histamine H2 receptor agonist. In turn, histamine H2 receptor inverse agonists interfere with histamine H1 receptor signaling. We also determine that the crossdesensitization induced by histamine H1 or H2 receptor agonists alters the histamine inverse agonists receptor response: activation of histamine H1 receptor affects cAMP response induced by histamine H2 receptor inverse agonists, whereas histamine H2 receptor agonist induces a negative regulation on the anti-inflammatory response of histamine H1 receptor inverse agonists. Binding studies revealed that histamine H1 and H2 receptors cointernalize after stimulus with histamine receptor inverse agonists. In addition, the inhibition of the internalization process prevents receptor crossregulation. Our study provides new insights in the mechanisms of action of histamine H1 and H2 receptors that explain the effect of histamine H1 and H2 receptor inverse agonists and opens up new venues for novel therapeutic applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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14. Participation of Gα i -Adenylate Cyclase and ERK1/2 in Mas Receptor Signaling Pathways.
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Burghi V, Echeverría EB, Sosa MH, Quiroga DT, Muñoz MC, Davio C, Monczor F, Fernández NC, and Dominici FP
- Abstract
The MasR receptor (MasR) is an orphan G protein-coupled receptor proposed as a candidate for mediating the angiotensin (Ang)-converting enzyme 2-Ang-(1-7) protective axis of renin-angiotensin system. This receptor has been suggested to participate in several physiological processes including cardio- and reno-protection and regulation of the central nervous system function. Although the knowledge of the signaling mechanisms associated with MasR is essential for therapeutic purposes, these are still poorly understood. Accordingly, in the current study we aimed to characterize the signaling pathways triggered by the MasR. To do that, we measured cAMP and Ca
2+ levels in both naïve and MasR transfected cells in basal conditions and upon incubation with putative MasR ligands. Besides, we evaluated activation of ERK1/2 by Ang-(1-7) in MasR transfected cells. Results indicated the existence of a high degree of MasR constitutive activity toward cAMP modulation. This effect was not mediated by the PDZ-binding motif of the MasR but by receptor coupling to Gαi-adenylyl cyclase signaling pathway. Incubation of MasR transfected cells with Ang-(1-7) or the synthetic ligand AVE 0991 amplified MasR negative modulation of cAMP levels. On the other hand, we provided evidence for lack of MasR-associated modulation of Ca2+ levels by Ang-(1-7). Finally, it was determined that the MasR attenuated Ang-(1-7)-induced ERK1/2 phosphorylation mediated by AT1R. We provided further characterization of MasR signaling mechanisms regarding its constitutive activity and response to putative ligands. This information could prove useful to better describe MasR physiological role and development of therapeutic agents that could modulate its action.- Published
- 2019
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15. Validation of commercial Mas receptor antibodies for utilization in Western Blotting, immunofluorescence and immunohistochemistry studies.
- Author
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Burghi V, Fernández NC, Gándola YB, Piazza VG, Quiroga DT, Guilhen Mario É, Felix Braga J, Bader M, Santos RAS, Dominici FP, and Muñoz MC
- Subjects
- Animals, Antibodies metabolism, Blotting, Western, Cell Line, Fluorescent Antibody Technique, HEK293 Cells, Humans, Immunohistochemistry, Kidney metabolism, Mice, Mice, Knockout, Myocardium metabolism, Proto-Oncogene Mas, Reverse Transcriptase Polymerase Chain Reaction, Proto-Oncogene Proteins metabolism, Proto-Oncogene Proteins c-myc metabolism, Receptors, G-Protein-Coupled metabolism
- Abstract
Mas receptor (MasR) is a G protein-coupled receptor proposed as a candidate for mediating the angiotensin (Ang)-converting enzyme 2-Ang (1-7) protective axis of renin-angiotensin system. Because the role of this receptor is not definitively clarified, determination of MasR tissue distribution and expression levels constitutes a critical knowledge to fully understanding its function. Commercially available antibodies have been widely employed for MasR protein localization and quantification, but they have not been adequately validated. In this study, we carried on an exhaustive evaluation of four commercial MasR antibodies, following previously established criteria. Western Blotting (WB) and immunohistochemistry studies starting from hearts and kidneys from wild type (WT) mice revealed that antibodies raised against different MasR domains yielded different patterns of reactivity. Furthermore, staining patterns appeared identical in samples from MasR knockout (MasR-KO) mice. We verified by polymerase chain reaction analysis that the MasR-KO mice used were truly deficient in this receptor as MAS transcripts were undetectable in either heart or kidney from this animal model. In addition, we evaluated the ability of the antibodies to detect the human c-myc-tagged MasR overexpressed in human embryonic kidney cells. Three antibodies were capable of detecting the MasR either by WB or by immunofluorescence, reproducing the patterns obtained with an anti c-myc antibody. In conclusion, although three of the selected antibodies were able to detect MasR protein at high expression levels observed in a transfected cell line, they failed to detect this receptor in mice tissues at physiological expression levels. As a consequence, validated antibodies that can recognize and detect the MasR at physiological levels are still lacking.
- Published
- 2017
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16. Modulation of the action of insulin by angiotensin-(1-7).
- Author
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Dominici FP, Burghi V, Muñoz MC, and Giani JF
- Subjects
- Angiotensin II metabolism, Angiotensin II Type 1 Receptor Blockers therapeutic use, Angiotensin-Converting Enzyme 2, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Animals, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 drug therapy, Humans, Hypoglycemic Agents therapeutic use, Peptidyl-Dipeptidase A metabolism, Proto-Oncogene Mas, Proto-Oncogene Proteins drug effects, Proto-Oncogene Proteins metabolism, Receptors, G-Protein-Coupled drug effects, Receptors, G-Protein-Coupled metabolism, Angiotensin I metabolism, Diabetes Mellitus, Type 2 metabolism, Insulin metabolism, Insulin Resistance, Peptide Fragments metabolism, Renin-Angiotensin System drug effects, Signal Transduction drug effects
- Abstract
The prevalence of Type 2 diabetes mellitus is predicted to increase dramatically over the coming years and the clinical implications and healthcare costs from this disease are overwhelming. In many cases, this pathological condition is linked to a cluster of metabolic disorders, such as obesity, systemic hypertension and dyslipidaemia, defined as the metabolic syndrome. Insulin resistance has been proposed as the key mediator of all of these features and contributes to the associated high cardiovascular morbidity and mortality. Although the molecular mechanisms behind insulin resistance are not completely understood, a negative cross-talk between AngII (angiotensin II) and the insulin signalling pathway has been the focus of great interest in the last decade. Indeed, substantial evidence has shown that anti-hypertensive drugs that block the RAS (renin-angiotensin system) may also act to prevent diabetes. Despite its long history, new components within the RAS continue to be discovered. Among them, Ang-(1-7) [angiotensin-(1-7)] has gained special attention as a counter-regulatory hormone opposing many of the AngII-related deleterious effects. Specifically, we and others have demonstrated that Ang-(1-7) improves the action of insulin and opposes the negative effect that AngII exerts at this level. In the present review, we provide evidence showing that insulin and Ang-(1-7) share a common intracellular signalling pathway. We also address the molecular mechanisms behind the beneficial effects of Ang-(1-7) on AngII-mediated insulin resistance. Finally, we discuss potential therapeutic approaches leading to modulation of the ACE2 (angiotensin-converting enzyme 2)/Ang-(1-7)/Mas receptor axis as a very attractive strategy in the therapy of the metabolic syndrome and diabetes-associated diseases.
- Published
- 2014
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17. Downregulation of the ACE2/Ang-(1-7)/Mas axis in transgenic mice overexpressing GH.
- Author
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Muñoz MC, Burghi V, Miquet JG, Giani JF, Banegas RD, Toblli JE, Fang Y, Wang F, Bartke A, and Dominici FP
- Subjects
- Angiotensin I pharmacology, Angiotensin-Converting Enzyme 2, Animals, Cardiovascular Diseases genetics, Cardiovascular Diseases metabolism, Down-Regulation genetics, Female, Growth Hormone genetics, Hypertension genetics, Hypertension metabolism, Kidney Diseases genetics, Kidney Diseases metabolism, Male, Mice, Mice, Inbred C3H, Mice, Inbred C57BL, Mice, Transgenic, Peptide Fragments pharmacology, Peptidyl-Dipeptidase A genetics, Proto-Oncogene Mas, Proto-Oncogene Proteins genetics, Receptors, G-Protein-Coupled genetics, Signal Transduction drug effects, Signal Transduction genetics, Angiotensin I metabolism, Growth Hormone metabolism, Peptide Fragments metabolism, Peptidyl-Dipeptidase A metabolism, Proto-Oncogene Proteins metabolism, Receptors, G-Protein-Coupled metabolism
- Abstract
The renin-angiotensin system (RAS) plays a crucial role in the regulation of physiological homeostasis and diseases such as hypertension, coronary artery disease, and chronic renal failure. In this cascade, the angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/AT1 receptor axis induces pathological effects, such as vasoconstriction, cell proliferation, and fibrosis, while the ACE2/Ang-(1-7)/Mas receptor axis is protective for end-organ damage. The altered function of the RAS could be a contributing factor to the cardiac and renal alterations induced by GH excess. To further explore this issue, we evaluated the consequences of chronic GH exposure on the in vivo levels of Ang II, Ang-(1-7), ACE, ACE2, and Mas receptor in the heart and the kidney of GH-transgenic mice (bovine GH (bGH) mice). At the age of 7-8 months, female bGH mice displayed increased systolic blood pressure (SBP), a high degree of both cardiac and renal fibrosis, as well as increased levels of markers of tubular and glomerular damage. Angiotensinogen abundance was increased in the liver and the heart of bGH mice, along with a concomitant increase in cardiac Ang II levels. Importantly, the levels of ACE2, Ang-(1-7), and Mas receptor were markedly decreased in both tissues. In addition, Ang-(1-7) administration reduced SBP to control values in GH-transgenic mice, indicating that the ACE2/Ang-(1-7)/Mas axis is involved in GH-mediated hypertension. The data indicate that the altered expression profile of the ACE2/Ang-(1-7)/Mas axis in the heart and the kidney of bGH mice could contribute to the increased incidence of hypertension, cardiovascular, and renal alterations observed in these animals.
- Published
- 2014
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18. Oral administration of angiotensin-(1-7) ameliorates type 2 diabetes in rats.
- Author
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Santos SH, Giani JF, Burghi V, Miquet JG, Qadri F, Braga JF, Todiras M, Kotnik K, Alenina N, Dominici FP, Santos RA, and Bader M
- Subjects
- Administration, Oral, Angiotensin I pharmacology, Animals, Animals, Newborn, Deoxyglucose metabolism, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 pathology, Hyperglycemia complications, Hyperglycemia drug therapy, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents pharmacology, Hypoglycemic Agents therapeutic use, Insulin metabolism, Male, Myocytes, Cardiac drug effects, Myocytes, Cardiac metabolism, Peptide Fragments pharmacology, Phosphorylation drug effects, Proto-Oncogene Proteins c-akt metabolism, Rats, Rats, Sprague-Dawley, Signal Transduction drug effects, Angiotensin I administration & dosage, Angiotensin I therapeutic use, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 prevention & control, Peptide Fragments administration & dosage, Peptide Fragments therapeutic use
- Abstract
Unlabelled: Diabetes mellitus type 2 (DM2) is a disease with increasing importance in modern societies and insufficient treatment options. Pharmacological stimulation of insulin signaling, which is blunted in DM2, is a promising approach to treat this disease. It has been shown that activation of the angiotensin (Ang)-(1-7)/Mas axis of the renin-angiotensin system leads to an improved glucose uptake. In this study, we intended to evaluate, whether this effect could be exploited therapeutically. We first confirmed that Ang-(1-7) improves insulin signaling and glucose uptake in vitro in cultured cardiomyocytes. We then evaluated the therapeutic effect of a newly developed hydro-xypropyl-β-cyclodextrin-based Ang-(1-7) nano-formulation in a novel transgenic rat model of inducible insulin resistance and DM2. The chronic administration of this compound prevented the marked elevation in blood glucose levels in these rats at a dose of 30 μg/kg, reversed the established hyperglycemic state at a dose of 100 μg/kg, and resulted in improved insulin sensitivity, reduced plasma insulin and decreased diabetic nephropathy. In conclusion, an oral Ang-(1-7) formulation reverses hyperglycemia and its consequences in an animal model of DM2 and represents a novel therapeutic option for the treatment of DM2 and other cardio-metabolic diseases., Key Message: A novel rat model with inducible diabetes can be used to evaluate new therapies. Angiotensin-(1-7) is effective in an oral formulation packaged in cyclodextrine. Angiotensin-(1-7) is a promising antidiabetic drug.
- Published
- 2014
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19. Upregulation of the angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas receptor axis in the heart and the kidney of growth hormone receptor knock-out mice.
- Author
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Giani JF, Miquet JG, Muñoz MC, Burghi V, Toblli JE, Masternak MM, Kopchick JJ, Bartke A, Turyn D, and Dominici FP
- Subjects
- Angiotensin I biosynthesis, Angiotensin-Converting Enzyme 2, Animals, Mice, Mice, Knockout, Peptide Fragments biosynthesis, Peptidyl-Dipeptidase A biosynthesis, Proto-Oncogene Mas, Proto-Oncogene Proteins biosynthesis, Receptors, G-Protein-Coupled biosynthesis, Angiotensin I genetics, Kidney metabolism, Myocardium metabolism, Peptide Fragments genetics, Peptidyl-Dipeptidase A genetics, Proto-Oncogene Proteins genetics, Receptors, G-Protein-Coupled genetics, Receptors, Somatotropin genetics, Up-Regulation
- Abstract
Objective: Growth hormone (GH) resistance leads to enhanced insulin sensitivity, decreased systolic blood pressure and increased lifespan. The aim of this study was to determine if there is a shift in the balance of the renin-angiotensin system (RAS) towards the ACE2/Ang-(1-7)/Mas receptor axis in the heart and the kidney of a model of GH resistance and retarded aging, the GH receptor knockout (GHR-/-) mouse., Design: RAS components were evaluated in the heart and the kidney of GHR-/- and control mice by immunohistochemistry and Western blotting (n=12 for both groups)., Results: The immunostaining of Ang-(1-7) was increased in both the heart and the kidney of GHR-/- mice. These changes were concomitant with an increased immunostaining of the Mas receptor and ACE2 in both tissues. The immunostaining of AT1 receptor was reduced in heart and kidney of GHR-/- mice while that of AT2 receptor was increased in the heart and unaltered in the kidney. Ang II, ACE and angiotensinogen levels remained unaltered in the heart and the kidney of GH resistant mice. These results were confirmed by Western blotting and correlated with a significant increase in the abundance of the endothelial nitric oxide synthase in both tissues., Conclusions: The shift within the RAS towards an exacerbation of the ACE2/Ang-(1-7)/Mas receptor axis observed in GHR-/- mice could be related to a protective role in cardiac and renal function; and thus, possibly contribute to the decreased incidence of cardiovascular diseases displayed by this animal model of longevity., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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20. The Mas receptor mediates modulation of insulin signaling by angiotensin-(1-7).
- Author
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Muñoz MC, Giani JF, Burghi V, Mayer MA, Carranza A, Taira CA, and Dominici FP
- Subjects
- Adipose Tissue drug effects, Adipose Tissue metabolism, Angiotensin I administration & dosage, Angiotensin II analogs & derivatives, Angiotensin II pharmacology, Animals, Blood Pressure, Dyslipidemias metabolism, Dyslipidemias pathology, Fructose administration & dosage, GTPase-Activating Proteins metabolism, Glycogen Synthase Kinase 3 metabolism, Glycogen Synthase Kinase 3 beta, Hypertension metabolism, Hypertension pathology, Insulin Resistance, Liver drug effects, Liver metabolism, Male, Muscle, Skeletal drug effects, Muscle, Skeletal metabolism, Peptide Fragments administration & dosage, Phosphorylation, Proto-Oncogene Mas, Proto-Oncogene Proteins antagonists & inhibitors, Proto-Oncogene Proteins c-akt metabolism, Rats, Rats, Sprague-Dawley, Receptors, G-Protein-Coupled antagonists & inhibitors, Angiotensin I pharmacology, Insulin metabolism, Peptide Fragments pharmacology, Proto-Oncogene Proteins metabolism, Receptors, G-Protein-Coupled metabolism, Signal Transduction
- Abstract
Angiotensin (Ang)-(1-7) stimulates proteins belonging to the insulin signaling pathway and ameliorates the Ang II negative effects at this level. However, up to date, receptors involved and mechanisms behind these observations remain unknown. Accordingly, in the present study, we explored the in vivo effects of antagonism of the Ang-(1-7) specific Mas receptor on insulin signal transduction in rat insulin-target tissues. We evaluated the acute modulation of insulin-stimulated phosphorylation of Akt, GSK-3β (Glycogen synthase kinase-3β) and AS160 (Akt substrate of 160kDa) by Ang-(1-7) and/or Ang II in the presence and absence of the selective Mas receptor antagonist A-779 in insulin-target tissues of normal rats. Also using A-779, we determined whether the Mas receptor mediates the improvement of insulin sensitivity exerted by chronic Ang-(1-7) treatment in fructose-fed rats (FFR), a model of insulin resistance, dyslipidemia and mild hypertension. The two major findings of the present work are as follows; 1) Ang-(1-7) attenuates acute Ang II-mediated inhibition of insulin signaling components in normal rats via a Mas receptor-dependent mechanism; and 2). The Mas receptor appears to be involved in beneficial effects of Ang-(1-7) on the phosphorylation of crucial insulin signaling mediators (Akt, GSK-3β and AS160), in liver, skeletal muscle and adipose tissue of FFR. These results shed light into the mechanism by which Ang-(1-7) exerts its positive physiological modulation of insulin actions in classical metabolic tissues and reinforces the central role of Akt in these effects., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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21. Angiotensin-(1-7) attenuates diabetic nephropathy in Zucker diabetic fatty rats.
- Author
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Giani JF, Burghi V, Veiras LC, Tomat A, Muñoz MC, Cao G, Turyn D, Toblli JE, and Dominici FP
- Subjects
- Acute-Phase Proteins metabolism, Animals, Blood Pressure drug effects, Diabetic Nephropathies metabolism, Diabetic Nephropathies pathology, Fibrosis, Hypertriglyceridemia drug therapy, Hypertriglyceridemia metabolism, Hypertriglyceridemia pathology, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Interleukin-6 metabolism, Kidney metabolism, Kidney pathology, Lipocalin-2, Lipocalins metabolism, Male, Oxidative Stress drug effects, Proteinuria metabolism, Proteinuria pathology, Proto-Oncogene Proteins metabolism, Rats, Rats, Zucker, Tumor Necrosis Factor-alpha metabolism, Angiotensin I therapeutic use, Diabetic Nephropathies drug therapy, Kidney drug effects, Peptide Fragments therapeutic use, Proteinuria drug therapy
- Abstract
Angiotensin (ANG)-(1-7) is known to attenuate diabetic nephropathy; however, its role in the modulation of renal inflammation and oxidative stress in type 2 diabetes is poorly understood. Thus in the present study we evaluated the renal effects of a chronic ANG-(1-7) treatment in Zucker diabetic fatty rats (ZDF), an animal model of type 2 diabetes and nephropathy. Sixteen-week-old male ZDF and their respective controls [lean Zucker rats (LZR)] were used for this study. The protocol involved three groups: 1) LZR + saline, 2) ZDF + saline, and 3) ZDF + ANG-(1-7). For 2 wk, animals were implanted with subcutaneous osmotic pumps that delivered either saline or ANG-(1-7) (100 ng·kg(-1)·min(-1)) (n = 4). Renal fibrosis and tissue parameters of oxidative stress were determined. Also, renal levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), ED-1, hypoxia-inducible factor-1α (HIF-1α), and neutrophil gelatinase-associated lipocalin (NGAL) were determined by immunohistochemistry and immunoblotting. ANG-(1-7) induced a reduction in triglyceridemia, proteinuria, and systolic blood pressure (SBP) together with a restoration of creatinine clearance in ZDF. Additionally, ANG-(1-7) reduced renal fibrosis, decreased thiobarbituric acid-reactive substances, and restored the activity of both renal superoxide dismutase and catalase in ZDF. This attenuation of renal oxidative stress proceeded with decreased renal immunostaining of IL-6, TNF-α, ED-1, HIF-1α, and NGAL to values similar to those displayed by LZR. Angiotensin-converting enzyme type 2 (ACE2) and ANG II levels remained unchanged after treatment with ANG-(1-7). Chronic ANG-(1-7) treatment exerts a renoprotective effect in ZDF associated with a reduction of SBP, oxidative stress, and inflammatory markers. Thus ANG-(1-7) emerges as a novel target for treatment of diabetic nephropathy.
- Published
- 2012
- Full Text
- View/download PDF
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