201
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Gandhi CK, Holmes R, Gewolb IH, Uhal BD. Degradation of Lung Protective Angiotensin Converting Enzyme-2 by Meconium in Human Alveolar Epithelial Cells: A Potential Pathogenic Mechanism in Meconium Aspiration Syndrome. Lung 2019; 197:227-233. [PMID: 30759273 PMCID: PMC7088148 DOI: 10.1007/s00408-019-00201-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/06/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Pancreatic digestive enzymes present in meconium might be responsible for meconium-induced lung injury. The local Renin Angiotensin System plays an important role in lung injury and inflammation. Particularly, angiotensin converting enzyme-2 (ACE-2) has been identified as a protective lung enzyme against the insult. ACE-2 converts pro-apoptotic Angiotensin II to anti-apoptotic Angiotensin 1-7. However, the effect of meconium on ACE-2 has never been studied before. OBJECTIVE To study the effect of meconium on ACE-2, and whether inhibition of proteolytic enzymes present in the meconium reverses its effects on ACE-2. METHODS Alveolar epithelial A549 cells were exposed to F-12 medium, 2.5% meconium, meconium + a protease inhibitor cocktail (PIc) and PIc alone for 16 h. At the end of incubation, apoptosis was measured with a nuclear fragmentation assay and cell lysates were collected for ACE-2 immunoblotting and enzyme activity. RESULTS Meconium caused a fourfold increase in apoptotic nuclei (p < 0.001). The pro-apoptotic effect of meconium can be reversed by PIc. Meconium reduced ACE-2 enzyme activity by cleaving ACE-2 into a fragment detected at ~ 37 kDa by immunoblot. PIc prevented the degradation of ACE-2 and restored 50% of ACE-2 activity (p < 0.05). CONCLUSION These data suggest that meconium causes degradation of lung protective ACE-2 by proteolytic enzymes present in meconium, since the effects of meconium can be reversed by PIc.
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Affiliation(s)
- Chintan K Gandhi
- Division of Neonatology, Department of Pediatrics & Human Development, Michigan State University, East Lansing, MI, USA.,Division of Neonatal Perinatal Medicine, Pennsylvania State Health Children's Hospital, Hershey, PA, USA
| | | | - Ira H Gewolb
- Division of Neonatology, Department of Pediatrics & Human Development, Michigan State University, East Lansing, MI, USA
| | - Bruce D Uhal
- Department of Physiology, Michigan State University, 3197 Biomedical and Physical Sciences Building, East Lansing, MI, 48824, USA.
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202
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Kuipers A, Moll GN, Wagner E, Franklin R. Efficacy of lanthionine-stabilized angiotensin-(1-7) in type I and type II diabetes mouse models. Peptides 2019; 112:78-84. [PMID: 30529303 DOI: 10.1016/j.peptides.2018.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/19/2022]
Abstract
Native angiotensin-(1-7) exerts many therapeutic effects. However, it is rapidly degraded by ACE and other peptidases. This drawback is largely eliminated for lanthionine-stabilized angiotensin-(1-7), termed cAng-(1-7), which is fully resistant to ACE and has strongly increased resistance to other peptidases. Goal of the present study was to test whether cAng-(1-7) has therapeutic activity in diabetes mouse models: in a multiple low dose streptozotocin-induced model of type I diabetes and / or in a db/db model of type II diabetes. In the type I diabetes model cAng-(1-7) caused in an increase in the insulin level of 133% in week 4 (p < 0.001) compared to vehicle, and in the type II diabetes model an increase of 55% of the insulin level in week 8 (p < 0.05) compared to vehicle. cAng-(1-7) reduced blood glucose levels in the type I model by 37% at day 22 (p < 0.001) and in the type II diabetes model by 17% at day 63 of treatment (p < 0.001) and in an oral glucose tolerance test in a type II diabetes model, by 17% at week 4 (p < 0.01). cAng-(1-7) also caused a reduction of glycated hemoglobin levels in the type II diabetes model of 21% in week 6 (p < 0,001). These data are consistent with therapeutic potential of cAng-(1-7) in type I and II diabetes.
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Affiliation(s)
- Anneke Kuipers
- Lanthio Pharma, a MorphoSys AG company, 9727 DL, Groningen, the Netherlands
| | - Gert N Moll
- Lanthio Pharma, a MorphoSys AG company, 9727 DL, Groningen, the Netherlands; Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, the Netherlands.
| | - Elizabeth Wagner
- Constant Pharmaceuticals LLC, 398 Columbus Ave, PMB 507, Boston, MA, 02116, USA
| | - Rick Franklin
- Constant Pharmaceuticals LLC, 398 Columbus Ave, PMB 507, Boston, MA, 02116, USA
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203
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Abstract
In the present chapter, we review and summarize current advances on the role of angiotensin-(1-7) [Ang-(1-7)] in the pathophysiology of main lung diseases: pulmonary hypertension (PH), acute respiratory distress syndrome (ARDS), asthma, and pulmonary fibrosis. Understanding the involvement of renin angiotensin system (RAS) in pulmonary inflammation may open new therapeutic possibilities for the treatment of respiratory diseases. Studies to date showed that Ang-(1-7) presents anti-inflammatory, antifibrotic activities and reduces pulmonary remodeling. These actions support the development of new pharmacological therapies based on the increase in Ang-(1-7) in the lungs to improve the treatment of inflammatory diseases.
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204
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Huang W, Cao Y, Liu Y, Ping F, Shang J, Zhang Z, Li Y. Activating Mas receptor protects human pulmonary microvascular endothelial cells against LPS-induced apoptosis via the NF-kB p65/P53 feedback pathways. J Cell Physiol 2018; 234:12865-12875. [PMID: 30537127 DOI: 10.1002/jcp.27951] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/19/2018] [Indexed: 01/08/2023]
Abstract
The balance between Ang II/AT1R and Ang-(1-7)/Mas plays a pivotal role in the development of lipopolysaccharides (LPS)-induced acute respiratory distress syndrome. However, the mechanisms underlying the balancing process still remain unclear. Here we investigated the roles of nuclear factor (NF)-κB and p53 in regulating AT1R and Mas expression. The results demonstrated that Ang II pretreatment resulted in downregulation of Mas and upregulation of AT1R, phosphorylated p65, and apoptosis in LPS-treated Human pulmonary microvascular endothelial cells (HPMVECs), but had no effect on p53 expression. Lentiviral vector-mediated P65 knockdown, but not a P53 knockdown, reversed all these effects of Ang II. On the other hand, Ang-(1-7) pretreatment lead to an increased in Mas expression and a decrease in AT1R, p53, and phosphorylated p65 expressions with suppressed apoptosis in LPS-treated cells. P65 knockdown promoted the protein expression of both AT1R and Mas while inhibiting p53 expression. P53 knockdown, but not a p65 knockdown, reversed all these effects of Ang-(1-7). Interestingly, p65 overexpression upregulated p53 and AT1R but downregulated Mas. P53 knockdown activated p65. These results suggest that there is a two-way feedback regulation between AT1R and Mas receptor via the NF-kB p65/P53 pathway, which may play a key role in LPS-induced HPMVECs apoptosis.
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Affiliation(s)
- Weifeng Huang
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Yongmei Cao
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Yujing Liu
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Feng Ping
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Jiawei Shang
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Zhongwei Zhang
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
| | - Yingchuan Li
- Department of Critical Care Medicine, Shanghai Jiaotong University affiliated to The Sixth People's Hospital, Shanghai, China
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205
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Santos RAS, Sampaio WO, Alzamora AC, Motta-Santos D, Alenina N, Bader M, Campagnole-Santos MJ. The ACE2/Angiotensin-(1-7)/MAS Axis of the Renin-Angiotensin System: Focus on Angiotensin-(1-7). Physiol Rev 2018; 98:505-553. [PMID: 29351514 PMCID: PMC7203574 DOI: 10.1152/physrev.00023.2016] [Citation(s) in RCA: 680] [Impact Index Per Article: 113.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The renin-angiotensin system (RAS) is a key player in the control of the cardiovascular system and hydroelectrolyte balance, with an influence on organs and functions throughout the body. The classical view of this system saw it as a sequence of many enzymatic steps that culminate in the production of a single biologically active metabolite, the octapeptide angiotensin (ANG) II, by the angiotensin converting enzyme (ACE). The past two decades have revealed new functions for some of the intermediate products, beyond their roles as substrates along the classical route. They may be processed in alternative ways by enzymes such as the ACE homolog ACE2. One effect is to establish a second axis through ACE2/ANG-(1-7)/MAS, whose end point is the metabolite ANG-(1-7). ACE2 and other enzymes can form ANG-(1-7) directly or indirectly from either the decapeptide ANG I or from ANG II. In many cases, this second axis appears to counteract or modulate the effects of the classical axis. ANG-(1-7) itself acts on the receptor MAS to influence a range of mechanisms in the heart, kidney, brain, and other tissues. This review highlights the current knowledge about the roles of ANG-(1-7) in physiology and disease, with particular emphasis on the brain.
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Affiliation(s)
- Robson Augusto Souza Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Walkyria Oliveira Sampaio
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Andreia C Alzamora
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Daisy Motta-Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Natalia Alenina
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Michael Bader
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
| | - Maria Jose Campagnole-Santos
- National Institute of Science and Technology in Nanobiopharmaceutics, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais , Belo Horizonte , Brazil ; Department of Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil ; Max-Delbrück-Center for Molecular Medicine (MDC), Berlin , Germany ; Berlin Institute of Health (BIH), Berlin , Germany ; Charité - University Medicine, Berlin , Germany ; DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin , Germany ; Institute for Biology, University of Lübeck , Lübeck , Germany
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206
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Xiao H, Liu X, Wang Y, Wang G, Yin C. Angiotensin‑(1‑7) prevents lipopolysaccharide‑induced hepatocellular inflammatory response by inhibiting the p38MAPK/AP‑1 signaling pathway. Mol Med Rep 2018; 17:5492-5497. [PMID: 29393446 DOI: 10.3892/mmr.2018.8527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 09/26/2017] [Indexed: 11/06/2022] Open
Abstract
The pathological mechanism of lipopolysaccharide (LPS)‑induced liver injury involves a number of inflammatory mediators and cytokines. Angiotensin (Ang)‑(1‑7), a ligand for the proto‑oncogene Mas (Mas) receptor, antagonizes the actions of Ang II in the renin angiotensin system and exerts an anti‑inflammatory effect on LPS‑induced macrophages. The present study investigated the potential role of Ang‑(1‑7) in the regulation of inflammatory responses in LPS‑induced hepatocytes using the rat liver BRL cell line. The results of the present study demonstrated that the inflammatory mediator, tumor necrosis factor (TNF)‑α, its upstream transcriptional regulatory factor activator protein (AP)‑1 and p38 mitogen activated protein kinase (MAPK) which were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting were upregulated in LPS‑induced hepatic cells in a time‑dependent manner, peaking 12 h following LPS stimulation. By contrast, treatment with Ang‑(1‑7) significantly attenuated the expression of TNF‑α, AP‑1 and p38MAPK in a concentration‑dependent manner. The anti‑inflammatory effect of Ang‑(1‑7) was reversed by the Mas receptor selective antagonist, A779, in BRL cells. Furthermore, the p38MAPK inhibitor, SB 203580, abolished the protective effects of Ang‑(1‑7), suggesting the involvement of the p38MAPK pathway in the anti‑inflammatory activity of Ang‑(1‑7). The results of the present study indicated that Ang‑(1‑7) may serve an anti‑inflammatory role in LPS‑induced hepatocyte injury via the regulation of the p38MAPK/AP‑1 signaling pathway.
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Affiliation(s)
- Hongli Xiao
- Department of Emergency Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Xiaoya Liu
- Department of Internal Medicine, Beijing Obstetrics and Gynaecology Hospital, Capital Medical University, Beijing 100026, P.R. China
| | - Yan Wang
- Department of Emergency Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Guoxing Wang
- Department of Emergency Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Chenghong Yin
- Department of Internal Medicine, Beijing Obstetrics and Gynaecology Hospital, Capital Medical University, Beijing 100026, P.R. China
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207
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Zhang H, Baker A. Recombinant human ACE2: acing out angiotensin II in ARDS therapy. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:305. [PMID: 29237475 PMCID: PMC5729230 DOI: 10.1186/s13054-017-1882-z] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/31/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Haibo Zhang
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Room 619, LKSKI, 30 Bond Street, Toronto, ON, M5B 1W8, Canada. .,Interdepartmental Division of Critical Care Medicine, Departments of Anesthesia and Physiology, University of Toronto, Toronto, ON, Canada.
| | - Andrew Baker
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Room 619, LKSKI, 30 Bond Street, Toronto, ON, M5B 1W8, Canada.,Interdepartmental Division of Critical Care Medicine, Departments of Anesthesia and Physiology, University of Toronto, Toronto, ON, Canada
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208
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Sodhi CP, Wohlford-Lenane C, Yamaguchi Y, Prindle T, Fulton WB, Wang S, McCray PB, Chappell M, Hackam DJ, Jia H. Attenuation of pulmonary ACE2 activity impairs inactivation of des-Arg 9 bradykinin/BKB1R axis and facilitates LPS-induced neutrophil infiltration. Am J Physiol Lung Cell Mol Physiol 2017; 314:L17-L31. [PMID: 28935640 DOI: 10.1152/ajplung.00498.2016] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is a terminal carboxypeptidase with important functions in the renin-angiotensin system and plays a critical role in inflammatory lung diseases. ACE2 cleaves single-terminal residues from several bioactive peptides such as angiotensin II. However, few of its substrates in the respiratory tract have been identified, and the mechanism underlying the role of ACE2 in inflammatory lung disease has not been fully characterized. In an effort to identify biological targets of ACE2 in the lung, we tested its effects on des-Arg9 bradykinin (DABK) in airway epithelial cells on the basis of the hypothesis that DABK is a biological substrate of ACE2 in the lung and ACE2 plays an important role in the pathogenesis of acute lung inflammation partly through modulating DABK/bradykinin receptor B1 (BKB1R) axis signaling. We found that loss of ACE2 function in mouse lung in the setting of endotoxin inhalation led to activation of the DABK/BKB1R axis, release of proinflammatory chemokines such as C-X-C motif chemokine 5 (CXCL5), macrophage inflammatory protein-2 (MIP2), C-X-C motif chemokine 1 (KC), and TNF-α from airway epithelia, increased neutrophil infiltration, and exaggerated lung inflammation and injury. These results indicate that a reduction in pulmonary ACE2 activity contributes to the pathogenesis of lung inflammation, in part because of an impaired ability to inhibit DABK/BKB1R axis-mediated signaling, resulting in more prompt onset of neutrophil infiltration and more severe inflammation in the lung. Our study identifies a biological substrate of ACE2 within the airways, as well as a potential new therapeutic target for inflammatory diseases.
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Affiliation(s)
- Chhinder P Sodhi
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | | | - Yukihiro Yamaguchi
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Thomas Prindle
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | - William B Fulton
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Sanxia Wang
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Paul B McCray
- Department of Pediatrics, Carver College of Medicine, The University of Iowa , Iowa City, Iowa
| | - Mark Chappell
- Hypertension and Vascular Research Center, Wake Forest School of Medicine , Winston-Salem, North Carolina
| | - David J Hackam
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
| | - Hongpeng Jia
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University , Baltimore, Maryland
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209
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Age-Dependent Changes in the Pulmonary Renin-Angiotensin System Are Associated With Severity of Lung Injury in a Model of Acute Lung Injury in Rats. Crit Care Med 2017; 44:e1226-e1235. [PMID: 27513359 DOI: 10.1097/ccm.0000000000002008] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVES A growing body of evidence suggests that age affects the main pathophysiologic mechanisms of the acute respiratory distress syndrome. This may imply the need for developing age-tailored therapies for acute respiratory distress syndrome. However, underlying molecular mechanisms governing age-related susceptibility first need to be unraveled. In a rat model of acute lung injury, we investigated whether age affects the balance between the two key enzymes of the pulmonary renin-angiotensin system, angiotensin-converting enzyme, and angiotensin-converting enzyme 2. We hypothesized that aging shifts the balance toward the lung injury-promoting angiotensin-converting enzyme, which may form an explanation for the differences in severity of lung injury between different age groups. DESIGN Prospective, randomized controlled animal study. SETTING University medical research laboratory. SUBJECTS Infant (15 ± 2 d), juvenile (37 ± 2 d), adult (4 ± 0.2 mo), and elderly (19.5 ± 0.5 mo) male RCCHan Wistar rats. INTERVENTIONS Lung injury was induced by intratracheal administration of lipopolysaccharide (5 mg/kg) and 4 hours of mechanical ventilation (15 mL/kg). MEASUREMENTS AND MAIN RESULTS In lipopolysaccharide-exposed and mechanical ventilated rats, angiotensin-converting enzyme activity in bronchoalveolar lavage fluid increased 3.2-fold in elderly when compared with infants. No changes in bronchoalveolar lavage fluid angiotensin-converting enzyme 2 activity were found. In addition, membrane-bound angiotensin-converting enzyme activity decreased. Together with the presence of angiotensin-converting enzyme-sheddase ADAM9 (a disintegrin and metalloproteinase domain-containing protein 9) and an age-dependent increase in tumor necrosis factor-α, an activator of ADAM9, these results indicate increased shedding of angiotensin-converting enzyme in the alveolar compartment, thereby shifting the balance toward the injurious pathway. This imbalance was associated with an increased inflammatory mediator response and more lung injury (wet-to-dry ratio and histology) in elderly rats. CONCLUSIONS Increasing age is associated with an imbalance of the pulmonary renin-angiotensin system, which correlates with aggravated inflammation and more lung injury. These changes might form the ground for new therapeutic strategies in terms of dosing and effectiveness of renin-angiotensin system-modulating agents for treatment of acute respiratory distress syndrome.
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210
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Wang K, Liu X, Xiao H, Wang H, Zhang Y. The correlation between inflammatory injury induced by LPS and RAS in EpH4-Ev cells. Int Immunopharmacol 2017; 46:23-30. [PMID: 28249221 DOI: 10.1016/j.intimp.2017.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 02/02/2017] [Accepted: 02/15/2017] [Indexed: 12/20/2022]
Abstract
Renin-angiotensin system (RAS) plays an important role of regulating inflammatory injury. However, it is not clear about the correlation between renin-angiotensin system (RAS) and inflammation induced by LPS in mammary gland cells. So immunofluorescence was performed to verify the ACE2 expression in mammary gland cells. MTT assay was performed to detect cell viability. ELISA was performed to detect cytokines in cell supernatant. Western Blot was performed to analyze RAS levels and ACE2 level change was observed by immunofluorescence. The TLR4 level and p65 phosphorylation were detected by Western Blot. The ACE2 protein intensively located on the cell membrane. According to the results of MTT assay and TNF-α level, the injury was evidently induced by high concentration LPS after 9h. The TNF-α, IL-6, IL-8, ACE, AT1R and AngII had an increasing expression with the rise of cell injury. In contrast, the MasR, Ang1-7 and ACE2 had a declining expression with the increase of cell injury degree. The TLR4 level and p65 phosphorylation in high concentration LPS group was significantly higher than that of control group. These results suggest that a valid inflammatory injury was induced after the cells were treated by high concentration of LPS for 9h. Meanwhile, the ACE/AngII/AT1R axis was activated and the ACE2/Ang1-7/MasR axis was depressed.
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Affiliation(s)
- Kun Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Xiaoqian Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Hang Xiao
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Huanhuan Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China
| | - Yuanshu Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang No.1, Nanjing 210095, China.
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211
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Plat A, Kuipers A, Crabb J, Rink R, Moll GN. Mutagenesis of nisin's leader peptide proline strongly modulates export of precursor nisin. Antonie van Leeuwenhoek 2016; 110:321-330. [PMID: 27830473 DOI: 10.1007/s10482-016-0802-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 11/04/2016] [Indexed: 11/25/2022]
Abstract
The lantibiotic nisin is produced by Lactococcus lactis as a precursor peptide comprising a 23 amino acid leader peptide and a 34 amino acid post-translationally modifiable core peptide. We previously demonstrated that the conserved FNLD part of the leader is essential for intracellular enzyme-catalyzed introduction of lanthionines in the core peptide and also for transporter-mediated export, whereas other positions are subject to large mutational freedom. We here demonstrate that, in the absence of the extracellular leader peptidase, NisP, export of precursor nisin via the modification and transporter enzymes, NisBTC, is strongly affected by multiple substitutions of the leader residue at position -2, but not by substitution of positions in the vicinity of this site. Export levels of precursor nisin increased by more than 70% for position -2 mutants Asp, Thr, Ser, Trp, Lys, Val and decreased more than 70% for Cys, His, Met. In a strain with leader peptidase, the Pro-2Lys and Pro-2Asp precursor nisins were less efficiently cleaved by NisP than wild type precursor nisin. Taken together, the wild type precursor nisin with a proline at position -2 allows balanced export and cleavage efficiencies by precursor nisin's transporter and leader peptidase.
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Affiliation(s)
- Annechien Plat
- Biomade Technology Foundation, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Gynecological Oncology, University Medical Center Groningen, 9700 RB, Groningen, The Netherlands
| | - Anneke Kuipers
- Lanthio Pharma, MorphoSys AG, Rozenburglaan 13B, 9727 DL, Groningen, The Netherlands
| | - Joe Crabb
- ImmuCell Corp., 56 Evergreen Drive, Portland, ME, 04130, USA
| | - Rick Rink
- Lanthio Pharma, MorphoSys AG, Rozenburglaan 13B, 9727 DL, Groningen, The Netherlands
| | - Gert N Moll
- Lanthio Pharma, MorphoSys AG, Rozenburglaan 13B, 9727 DL, Groningen, The Netherlands.
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.
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212
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Fedson DS. Treating the host response to emerging virus diseases: lessons learned from sepsis, pneumonia, influenza and Ebola. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:421. [PMID: 27942512 DOI: 10.21037/atm.2016.11.03] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
There is an ongoing threat of epidemic or pandemic diseases that could be caused by influenza, Ebola or other emerging viruses. It will be difficult and costly to develop new drugs that target each of these viruses. Statins and angiotensin receptor blockers (ARBs) have been effective in treating patients with sepsis, pneumonia and influenza, and a statin/ARB combination appeared to dramatically reduce mortality during the recent Ebola outbreak. These drugs target (among other things) the endothelial dysfunction found in all of these diseases. Most scientists work on new drugs that target viruses, and few accept the idea of treating the host response with generic drugs. A great deal of research will be needed to show conclusively that these drugs work, and this will require the support of public agencies and foundations. Investigators in developing countries should take an active role in this research. If the next Public Health Emergency of International Concern is caused by an emerging virus, a "top down" approach to developing specific new drug treatments is unlikely to be effective. However, a "bottom up" approach to treatment that targets the host response to these viruses by using widely available and inexpensive generic drugs could reduce mortality in any country with a basic health care system. In doing so, it would make an immeasurable contribution to global equity and global security.
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Affiliation(s)
- David S Fedson
- Formerly, Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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213
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Captopril improves postresuscitation hemodynamics protective against pulmonary embolism by activating the ACE2/Ang-(1-7)/Mas axis. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:1159-1169. [PMID: 27449068 DOI: 10.1007/s00210-016-1278-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/14/2016] [Indexed: 01/07/2023]
Abstract
Acute pulmonary embolism (APE) has a very high mortality rate, especially at cardiac arrest and even after the return of spontaneous circulation (ROSC). This study investigated the protective effect of the angiotensin-converting enzyme (ACE) inhibitor captopril on postresuscitation hemodynamics, in a porcine model of cardiac arrest established by APE. Twenty-nine Beijing Landrace pigs were infused with an autologous thrombus leading to cardiac arrest and subjected to standard cardiopulmonary resuscitation and thrombolysis. Ten resuscitated pigs were randomly and equally apportioned to receive either captopril (22.22 mg/kg) infusion or the same volume saline, 30 min after ROSC. Hemodynamic changes and ACE-Ang II-angiotensin II type 1 receptor (AT1R) and ACE2/Ang-(1-7)/Mas receptor axis levels were determined. APE was associated with a decline in mean arterial pressure and a dramatic increase in pulmonary artery pressure and mean right ventricular pressure. After ROSC, captopril infusion was associated with significantly lower mean right ventricular pressure and systemic and pulmonary vascular resistance, faster heart rate, and higher Ang-(1-7) levels, ACE2/ACE, and Ang-(1-7)/Ang II, compared with the saline infusion. The ACE2/Ang-(1-7)/Mas pathway correlated negatively with external vascular lung water and pulmonary vascular permeability and positively with the right cardiac index. In conclusion, in a pig model of APE leading to cardiac arrest, captopril infusion was associated with less mean right ventricular pressure overload after resuscitation, compared with saline infusion. The reduction in systemic and pulmonary vascular resistance associated with captopril may be by inhibiting the ACE-Ang II-AT1R axis and activating the ACE2/Ang-(1-7)/Mas axis.
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214
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Angiotensin-converting enzyme 2 prevents lipopolysaccharide-induced rat acute lung injury via suppressing the ERK1/2 and NF-κB signaling pathways. Sci Rep 2016; 6:27911. [PMID: 27302421 PMCID: PMC4908402 DOI: 10.1038/srep27911] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/26/2016] [Indexed: 12/20/2022] Open
Abstract
Acute respiratory distress syndrome (ARDS) caused by severe sepsis remains a major challenge in intensive care medicine. ACE2 has been shown to protect against lung injury. However, the mechanisms of its protective effects on ARDS are largely unknown. Here, we report that ACE2 prevents LPS-induced ARDS by inhibiting MAPKs and NF-κB signaling pathway. Lentiviral packaged Ace2 cDNA or Ace2 shRNA was intratracheally administrated into the lungs of male SD rats. Two weeks after gene transfer, animals received LPS (7.5 mg/Kg) injection alone or in combination with Mas receptor antagonist A779 (10 μg/Kg) or ACE2 inhibitor MLN-4760 (1 mg/Kg) pretreatment. LPS-induced lung injury and inflammatory response were significantly prevented by ACE2 overexpression and deteriorated by Ace2 shRNA. A779 or MLN-4760 pretreatment abolished the protective effects of ACE2. Moreover, overexpression of ACE2 significantly reduced the Ang II/Ang-(1-7) ratio in BALF and up-regulated Mas mRNA expression in lung, which was reversed by A779. Importantly, the blockade of ACE2 on LPS-induced phosphorylation of ERK1/2, p38 and p50/p65 was also abolished by A779. Whereas, only the ERK1/2 inhibitor significantly attenuated lung injury in ACE2 overexpressing rats pretreated with A779. Our observation suggests that AEC2 attenuates LPS-induced ARDS via the Ang-(1-7)/Mas pathway by inhibiting ERK/NF-κB activation.
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215
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Supé S, Kohse F, Gembardt F, Kuebler WM, Walther T. Therapeutic time window for angiotensin-(1-7) in acute lung injury. Br J Pharmacol 2016; 173:1618-28. [PMID: 26895462 DOI: 10.1111/bph.13462] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/11/2016] [Accepted: 02/12/2016] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE There is presently no proven pharmacological therapy for the acute respiratory distress syndrome. Recently, we and others discovered that the heptapeptide angiotensin-(1-7) [Ang-(1-7)] shows significant beneficial effects in preclinical models of acute lung injury (ALI). Here, we aimed to identify the best time window for Ang-(1-7) administration to protect rats from oleic acid (OA) induced ALI. EXPERIMENTAL APPROACH The effects of i.v. infused Ang-(1-7) were examined over four different time windows before or after induction of ALI in male Sprague-Dawley rats. Haemodynamic effects were continuously monitored, and loss of barrier function, inflammation and lung peptidase activities were measured as experimental endpoints. KEY RESULTS Ang-(1-7) infusion provided the best protection against experimental ALI when administered by continuous infusion starting immediately after 30 min OA infusion till the end of the experiment (30-240 min). Both pretreatment (-60 to 0 min before OA) and short-term therapy (30-90 min) also had beneficial effects although less pronounced than the effects achieved with the optimal therapy window. Starting infusion of Ang-(1-7) 60 min after the end of OA treatment (90-240 min) did not protect barrier function or haemodynamics but still reduced myeloperoxidase activity and increased ACE2/ACE activity ratio respectively. CONCLUSIONS AND IMPLICATIONS Our findings indicate that early initiation of therapy after ALI and continuous drug delivery are most beneficial for optimal therapeutic efficiency of Ang-(1-7) treatment in experimental ALI and, presumably accordingly, in clinical acute respiratory distress syndrome.
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Affiliation(s)
- Stefanie Supé
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Franziska Kohse
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Center for Perinatal Medicine, Clinic of Paediatric Surgery, University of Leipzig, Leipzig, Germany
| | - Florian Gembardt
- Department of Cardiac Pathobiology, Excellence Cluster Cardiopulmonary System, Gießen, Germany.,Department of Nephrology-MK3, University Hospital Dresden, Dresden, Germany
| | - Wolfgang M Kuebler
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Keenan Research Centre for Biomedical Science, St Michael's Hospital, Toronto, ON, Canada.,Departments of Physiology and Surgery, University of Toronto, Ontario, Canada.,German Heart Institute, Berlin, Germany
| | - Thomas Walther
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland.,Center for Perinatal Medicine, Department of Obstetrics, University of Leipzig, Leipzig, Germany
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216
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Neuroprotective mechanisms of the ACE2-angiotensin-(1-7)-Mas axis in stroke. Curr Hypertens Rep 2016; 17:3. [PMID: 25620630 DOI: 10.1007/s11906-014-0512-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The discovery of beneficial neuroprotective effects of the angiotensin converting enzyme 2-angiotensin-(1-7)-Mas axis [ACE2-Ang-(1-7)-Mas] in ischemic and hemorrhagic stroke has spurred interest in a more complete characterization of its mechanisms of action. Here, we summarize findings that describe the protective role of the ACE2-Ang-(1-7)-Mas axis in stroke, along with a focused discussion on the potential mechanisms of neuroprotective effects of Ang-(1-7) in stroke. The latter incorporates evidence describing the actions of Ang-(1-7) to counter the deleterious effects of angiotensin II (AngII) via its type 1 receptor, including anti-inflammatory, anti-oxidant, vasodilatory, and angiogenic effects, and the role of altered kinase-phosphatase signaling. Interactions of Mas with other receptors, including bradykinin receptors and AngII type 2 receptors are also considered. A more complete understanding of the mechanisms of action of Ang-(1-7) to elicit neuroprotection will serve as an essential step toward research into potential targeted therapeutics in the clinical setting.
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217
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Angiotensin-converting enzyme inhibition attenuates lipopolysaccharide-induced lung injury by regulating the balance between angiotensin-converting enzyme and angiotensin-converting enzyme 2 and inhibiting mitogen-activated protein kinase activation. Shock 2016; 43:395-404. [PMID: 25768373 DOI: 10.1097/shk.0000000000000302] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Activation of the renin-angiotensin system (angiotensin-converting enzyme [ACE]/angiotensin II [Ang II] and angiotensin-converting enzyme 2 [ACE2]/Ang-1-7) has been implicated in the pathophysiology of inflammatory response and acute lung injury (ALI). Previous studies have shown that the ACE inhibitor captopril (Cap) may be a potent therapeutic drug for ALI. However, the mechanisms of its protective effects on ALI are still largely unknown. In this study, we evaluated the effects of Cap on preventing lipopolysaccharide (LPS)-induced lung injury and further investigated the underlying mechanisms of these protective effects. Rats were intraperitoneally pretreated with Cap (50 mg/kg) 30 min prior to an intravenous administration of LPS (7.5 mg/kg). Furthermore, following a 30-min pretreatment with Cap (10 mol/mL) or combined with the ACE2 inhibitor MLN4760 (10 mol/mL), rat pulmonary microvascular endothelial cells (PMVECs) were stimulated with LPS (1 mg/mL). Captopril pretreatment significantly attenuated LPS-induced pathophysiological changes in the lung, inhibited secretion of tumor necrosis factor α and interleukin 6, reduced the ratio of Ang II to Ang-1-7, and reversed the increased ratio of ACE to ACE2, which was remarkably decreased from 7.07 (LPS only) to 1.71 (LPS + Cap). The protective effects of Cap on ALI were also confirmed by in vitro studies, in which Cap suppressed LPS-induced secretion of proinflammatory cytokines and modulated the expression levels of ACE and ACE2. After Cap pretreatment, the ratio of ACE to ACE2 expression was remarkably decreased from 5.18 (LPS alone) to 1.52 (LPS + Cap). Furthermore, Cap given before LPS administration led to inhibition of p38 mitogen-activated protein kinase (MAPK), ERK (extracellular signal-regulated kinase) 1/2, and JNK (c-Jun N-terminal kinase) phosphorylation in PMVECs, whereas MLN4760 abolished the protective effects of Cap on LPS-induced secretion of proinflammatory cytokines and abolished Cap-induced blockade of p38MAPK, ERK1/2, and JNK phosphorylation. Our findings reveal that Cap exerts protective effects on LPS-induced lung injury and the cytotoxicity of PMVECs, and these effects may, at least in part, regulate the balance of ACE and ACE2 expression and inhibit the activation of MAPKs.
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218
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Gaddam RR, Ang AD, Badiei A, Chambers ST, Bhatia M. Alteration of the renin-angiotensin system in caerulein induced acute pancreatitis in the mouse. Pancreatology 2015; 15:647-53. [PMID: 26444748 DOI: 10.1016/j.pan.2015.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/28/2015] [Accepted: 09/15/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND The objective of this study was to determine if RAS bioactive enzymes and peptides are perturbed in acute pancreatitis and associated lung injury. METHODS The intervention group of mice were treated with ten hourly intraperitoneal (i.p.) injections of caerulein (50 μg/kg) to induce acute pancreatitis. Animals were euthanized, samples of pancreas, lung and blood were collected, and plasma was prepared and stored for subsequent analysis. ACE and ACE2 activities were determined by spectrofluorometric assay. ACE, ACE2, Ang II and Ang-(1-7) levels were quantified by ELISA. RESULTS There was a significant decrease in ACE2 enzymatic activity in pancreatic and lung tissues of mice with acute pancreatitis. In contrast, there were no significant changes in measured levels of ACE and ACE2 in the pancreas, and lung or activity of ACE in pancreatic and lung tissue following acute pancreatitis. There were no significant differences in the activities and levels of circulating ACE and ACE2 following acute pancreatitis. The ACE to ACE2 activity ratio was markedly increased in pancreatic and lung tissues of mice with acute pancreatitis. No significant changes were observed in the levels of Ang II except for a decrease in lung tissue. No changes were observed in Ang-(1-7) levels in pancreas, lung and plasma between the groups. The Ang II to Ang-(1-7) ratio was increased in the pancreas but was decreased in the lung following caerulein treatment. CONCLUSION These data suggest dysregulation of RAS in acute pancreatitis as evidenced by altered Ang II/Ang-(1-7) levels induced by the imbalance of ACE/ACE2 activity.
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Affiliation(s)
| | - Abel Damien Ang
- Department of Pathology, University of Otago, Christchurch, New Zealand
| | - Alireza Badiei
- Department of Pathology, University of Otago, Christchurch, New Zealand
| | | | - Madhav Bhatia
- Department of Pathology, University of Otago, Christchurch, New Zealand.
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219
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Chen K, Bi J, Su Y, Chappell MC, Rose JC. Sex-Specific Changes in Renal Angiotensin-Converting Enzyme and Angiotensin-Converting Enzyme 2 Gene Expression and Enzyme Activity at Birth and Over the First Year of Life. Reprod Sci 2015; 23:200-10. [PMID: 26243544 DOI: 10.1177/1933719115597760] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) are key enzymes of the renin-angiotensin system. We investigated developmental changes in renal ACE and ACE2 gene expression and activity in both male and female sheep. METHODS Three groups of sheep (fetus, newborn, and adult) were used. Renal ACE and ACE2 activities, messenger RNA (mRNA), and protein expression were studied. RESULTS Renal ACE and ACE2 activities increased at 1 year in males, while there were no changes throughout development in females. Renal ACE and ACE2 mRNA and protein showed no sex differences but increased by 1 year of age. CONCLUSION There are sex-related differences in the development of renal-converting enzyme activities that may have functional implications in terms of the regulation of blood pressure and renal function in men and women. The difference in the patterns of gene expression and enzyme activity indicates that changes in gene expression may not accurately reflect changes in activity.
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Affiliation(s)
- Kai Chen
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jianli Bi
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA Center of Research for Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Yixin Su
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA Center of Research for Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Mark C Chappell
- Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - James C Rose
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA Center of Research for Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC, USA
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220
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Oliveira-Lima OC, Pinto MCX, Duchene J, Qadri F, Souza LL, Alenina N, Bader M, Santos RAS, Carvalho-Tavares J. Mas receptor deficiency exacerbates lipopolysaccharide-induced cerebral and systemic inflammation in mice. Immunobiology 2015; 220:1311-21. [PMID: 26297425 DOI: 10.1016/j.imbio.2015.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 12/11/2022]
Abstract
Beyond the classical actions of the renin-angiotensin system on the regulation of cardiovascular homeostasis, several studies have shown its involvement in acute and chronic inflammation. The G protein-coupled receptor Mas is a functional binding site for the angiotensin-(1-7); however, its role in the immune system has not been fully elucidated. In this study, we evaluated the effect of genetic deletion of Mas receptor in lipopolysaccharide (LPS)-induced systemic and cerebral inflammation in mice. Inflammatory response was triggered in Mas deficient (Mas(-/-)) and C57BL/6 wild-type (WT) mice (8-12 weeks-old) by intraperitoneal injection of LPS (5 mg/kg). Mas(-/-) mice presented more intense hypothermia compared to WT mice 24 h after LPS injection. Systemically, the bone marrow of Mas(-/-) mice contained a lower number of neutrophils and monocytes 3 h and 24 h after LPS injection, respectively. The plasma levels of inflammatory mediators KC, MCP-1 and IL-10 were higher in Mas(-/-) mice 24 h after LPS injection in comparison to WT. In the brain, Mas(-/-) animals had a significant increase in the number of adherent leukocytes to the brain microvasculature compared to WT mice, as well as, increased number of monocytes and neutrophils recruited to the pia-mater. The elevated number of adherent leukocytes on brain microvasculature in Mas(-/-) mice was associated with increased expression of CD11b - the alpha-subunit of the Mac-1 integrin - in bone marrow neutrophils 3h after LPS injection, and with increased brain levels of chemoattractants KC, MIP-2 and MCP-1, 24 h later. In conclusion, we demonstrated that Mas receptor deficiency results in exacerbated inflammation in LPS-challenged mice, which suggest a potential role for the Mas receptor as a regulator of systemic and brain inflammatory response induced by LPS.
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Affiliation(s)
- Onésia C Oliveira-Lima
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Mauro C X Pinto
- Departamento de Cirurgia, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Johan Duchene
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Laura L Souza
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Instituto Sírio-Libanês de Ensino e Pesquisa, São Paulo, Brazil
| | - Natalia Alenina
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Michael Bader
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Robson A S Santos
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juliana Carvalho-Tavares
- Departamento de Fisiologia e Biofísica, Instituto de Ciência Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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221
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Yuan YM, Luo L, Guo Z, Yang M, Ye RS, Luo C. Activation of renin-angiotensin-aldosterone system (RAAS) in the lung of smoking-induced pulmonary arterial hypertension (PAH) rats. J Renin Angiotensin Aldosterone Syst 2015; 16:249-53. [PMID: 25795458 PMCID: PMC7234796 DOI: 10.1177/1470320315576256] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/23/2014] [Indexed: 02/05/2023] Open
Abstract
Objectives: To explore the role of the renin–angiotensin–aldosterone system (RAAS) in the
pathogenesis of pulmonary arterial hypertension (PAH) induced by chronic
exposure to cigarette smoke. Methods: 48 healthy male SD rats were randomly divided into four groups (12/group):
control group (group A); inhibitor alone group (group B); cigarette
induction group (group C); cigarette induction + inhibitor group (group D).
After the establishment of smoking-induced PAH rat model, the right
ventricular systolic pressure (RVSP) was detected using an inserted
catheter; western blotting was used to detect the protein expression of
angiotensin-converting enzyme-2 (ACE2) and angiotensin-converting enzyme
(ACE); expression levels of angiotensin II (AngII) in lung tissue were
measured by radioimmunoassay. Results: After six months of cigarette exposure, the RVSP of chronic cigarette
induction group was significantly higher than that of the control group;
expression levels of AngII and ACE increased in lung tissues, but ACE2
expression levels reduced. Compared with cigarette exposure group, after
losartan treatment, RVSP, ACE and AngII obviously decreased
(P<0.05), and ACE2 expression levels significantly
increased. Conclusion: Chronic cigarette exposure may result in PAH and affect the protein
expression of ACE2 and ACE in lung tissue, suggesting that ACE2 and ACE play
an important role in the pathogenesis of smoking-induced PAH.
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Affiliation(s)
- Yi-Ming Yuan
- Department of Geriatric Medicine, West China Hospital, Sichuan University, China
| | - Li Luo
- Department of Geriatric Medicine, West China Hospital, Sichuan University, China
| | - Zhen Guo
- ENT Department, Pixian TCM Hospital, China
| | - Ming Yang
- Department of Geriatric Medicine, West China Hospital, Sichuan University, China
| | - Ren-Song Ye
- Department of Internal Medicine, The Affiliated Shanghai Eighth People's Hospital of Jiangsu University,Shanghai, China
| | - Chuan Luo
- Department of Geriatric Medicine, West China Hospital, Sichuan University, China
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Zambelli V, Bellani G, Borsa R, Pozzi F, Grassi A, Scanziani M, Castiglioni V, Masson S, Decio A, Laffey JG, Latini R, Pesenti A. Angiotensin-(1-7) improves oxygenation, while reducing cellular infiltrate and fibrosis in experimental Acute Respiratory Distress Syndrome. Intensive Care Med Exp 2015. [PMID: 26215809 PMCID: PMC4512981 DOI: 10.1186/s40635-015-0044-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background The renin-angiotensin system (RAS) plays a role in the pathogenesis of ARDS, Angiotensin II (Ang-II) contributing to the pathogenesis of inflammation and fibrogenesis. Angiotensin-(1-7) (Ang-(1-7)) may antagonize the effects of Ang-II. This study was aimed at evaluating the potential for Ang-(1-7) to reduce injury, inflammation and fibrosis in an experimental model of ARDS in the acute and late phases. Methods Male Sprague Dawley rats underwent an instillation of 0.1 M hydrochloric acid (HCl, 2.5 ml/kg) into the right bronchus. In an acute ARDS study, acid-injured rats were subjected to high stretch mechanical ventilation (18 ml/kg) for 5 h and randomized to receive an intravenous infusion of either vehicle (saline), Ang-(1-7) at low dose(0.27 μg/kg/h) (ALD), or high dose (60 μg/kg/h) (AHD) starting simultaneously with injury or 2 h afterwards. Arterial blood gas analysis and bronchoalveolar lavage (BAL) were performed to assess the injury. For the late ARDS study, after HCl instillation rats were randomized to either vehicle or high dose Ang-(1-7) (300 μg/kg/day) infused by mini osmotic pumps for two weeks, and lung hydroxyproline content measured. Results In the acute ARDS study, Ang-(1-7) led to a significant improvement in oxygenation (PaO2/FiO2 : vehicle 359 ± 86; ALD 436 ± 72; AHD 44 442 ± 56; ANOVA p = 0.007) and reduced white blood cells counts (vehicle 4,519 ± 2,234; ALD 2,496 ± 621; AHD 2,744 ± 119/mm3; ANOVA p = 0.004). Only treatment with high dose Ang-(1-7) reduced inflammatory cell numbers in BAL (vehicle 127 ± 34; AHD 96 ± 34/ μl; p = 0.033). Interestingly also delayed administration of Ang-(1-7) was effective in reducing injury. In later ARDS, Ang-(1-7) decreased hydroxyproline content (649 ± 202 and 1,117 ± 297 μg/lung; p < 0.05). Conclusions Angiotensin-(1-7), decreased the severity of acute lung injury and inflammation induced by combined acid aspiration and high stretch ventilation. Furthermore, continuous infusion of Ang-(1-7) reduced lung fibrosis 2 weeks following acid aspiration injury. These results call for further research on Ang-(1-7) as possible therapy for ARDS.
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Affiliation(s)
- Vanessa Zambelli
- Department of Health Sciences, University of Milano-Bicocca, Monza, Italy,
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Angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis prevents lipopolysaccharide-induced apoptosis of pulmonary microvascular endothelial cells by inhibiting JNK/NF-κB pathways. Sci Rep 2015; 5:8209. [PMID: 25644821 PMCID: PMC4314638 DOI: 10.1038/srep08209] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 01/13/2015] [Indexed: 01/01/2023] Open
Abstract
ACE2 and Ang–(1–7) have important roles in preventing acute lung injury. However, it is not clear whether upregulation of the ACE2/Ang–(1–7)/Mas axis prevents LPS–induced injury in pulmonary microvascular endothelial cells (PMVECs) by inhibiting the MAPKs/NF–κB pathways. Primary cultured rat PMVECs were transduced with lentiviral–borne Ace2 or shRNA–Ace2, and then treated or not with Mas receptor blocker (A779) before exposure to LPS. LPS stimulation resulted in the higher levels of AngII, Ang–(1–7), cytokine secretion, and apoptosis rates, and the lower ACE2/ACE ratio. Ace2 reversed the ACE2/ACE imbalance and increased Ang–(1–7) levels, thus reducing LPS–induced apoptosis and inflammation, while inhibition of Ace2 reversed all these effects. A779 abolished these protective effects of Ace2. LPS treatment was associated with activation of the ERK, p38, JNK, and NF–κB pathways, which were aggravated by A779. Pretreatment with A779 prevented the Ace2–induced blockade of p38, JNK, and NF–κB phosphorylation. However, only JNK inhibitor markedly reduced apoptosis and cytokine secretion in PMVECs with Ace2 deletion and A779 pretreatment. These results suggest that the ACE2/Ang–(1–7)/Mas axis has a crucial role in preventing LPS–induced apoptosis and inflammation of PMVECs, by inhibiting the JNK/NF–κB pathways.
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Abstract
The renin-angiotensin (Ang) system is involved in maintaining cardiovascular function by regulating blood pressure and electrolyte homeostasis. More recently, alternative pathways within the renin-angiotensin system have been described, such as the ACE-2/Ang-(1-7)/Mas axis, with opposite effects to the ones of the ACE/Ang-II/AT1 axis. Correspondingly, our previous work reported that Ang-(1-7) via its receptor Mas inhibits the mRNA expression of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor-α increased by lipopolysaccharide (LPS) in mouse peritoneal macrophages. These data led us to investigate the functional role of the Ang-(1-7)/Mas axis in an in vivo LPS model. In this work, we present evidence that Ang-(1-7) via Mas significantly reduced the LPS-increased production of circulating cytokines, such as IL-6, IL-12, and CXCL-1. This inhibitory effect was mediated by Mas because it was not detectable in Mas-deficient (Mas) mice. Accordingly, IL-6, CXCL-1, and CXCL-2 levels were higher after LPS treatment in the absence of Mas. Mas mice were less resistant to LPS-induced endotoxemia, their survival rate being 50% compared with 95% in wild-type mice. Telemetric analyses showed that Mas mice presented more pronounced LPS-induced hypothermia with a 3°C lower body temperature compared with wild-type mice. Altogether, our findings suggest that Ang-(1-7) and Mas inhibit LPS-induced cytokine production and hypothermia and thereby protect mice from the fatal consequences of endotoxemia.
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225
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He H, Liu L, Chen Q, Liu A, Cai S, Yang Y, Lu X, Qiu H. Mesenchymal Stem Cells Overexpressing Angiotensin-Converting Enzyme 2 Rescue Lipopolysaccharide-Induced Lung Injury. Cell Transplant 2014; 24:1699-715. [PMID: 25291359 DOI: 10.3727/096368914x685087] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bone marrow-derived mesenchymal stem cells (MSCs), which have beneficial effects in acute lung injury (ALI), can serve as a vehicle for gene therapy. Angiotensin-converting enzyme 2 (ACE2), a counterregulatory enzyme of ACE that degrades angiotensin (Ang) II into Ang 1-7, has a protective role against ALI. Because ACE2 expression is severely reduced in the injured lung, a therapy targeted to improve ACE2 expression in lung might attenuate ALI. We hypothesized that MSCs overexpressing ACE2 would have further benefits in lipopolysaccharide (LPS)-induced ALI mice, when compared with MSCs alone. MSCs were transduced with ACE2 gene (MSC-ACE2) by a lentiviral vector and then infused into wild-type (WT) and ACE2 knockout (ACE2(-/y)) mice following an LPS-induced intratracheal lung injury. The results demonstrated that the lung injury of ALI mice was alleviated at 24 and 72 h after MSC-ACE2 transplantation. MSC-ACE2 improved the lung histopathology and had additional anti-inflammatory effects when compared with MSCs alone in both WT and ACE2(-/y) ALI mice. MSC-ACE2 administration also reduced pulmonary vascular permeability, improved endothelial barrier integrity, and normalized lung eNOS expression relative to the MSC group. The beneficial effects of MSC-ACE2 could be attributed to its recruitment into the injured lung and enhanced local expression of ACE2 protein without changing the serum ACE2 levels after MSC-ACE2 transplantation. The biological activity of the increased ACE2 protein decreased the Ang II amount and increased the Ang 1-7 level in the lung when compared with the ALI and MSC-only groups, thereby inhibiting the detrimental effects of accumulating Ang II. Therefore, compared to MSCs alone, the administration of MSCs overexpressing ACE2 resulted in a further improvement in the inflammatory response and pulmonary endothelial function of LPS-induced ALI mice. These additional benefits could be due to the degradation of Ang II that accompanies the targeted overexpression of ACE2 in the lung.
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Affiliation(s)
- Hongli He
- Department of Critical Care Medicine, Zhongda Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, P. R. China
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226
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Xue T, Wei N, Xin Z, Qingyu X. Angiotensin-converting enzyme-2 overexpression attenuates inflammation in rat model of chronic obstructive pulmonary disease. Inhal Toxicol 2014; 26:14-22. [PMID: 24417403 DOI: 10.3109/08958378.2013.850563] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To investigate the anti-inflammatory effects of angiotensin-converting enzyme 2 (ACE2) overexpression on rat model of chronic obstructive pulmonary disease (COPD), and explore underlying mechanism. METHODS The rat COPD model was established by cigarette smoking using a total body exposure method. A total of 64 male Wistar rats were randomly divided into four groups: normal, COPD, Ad-ACE2 and Ad-EGFP groups. The COPD model rats (including COPD, Ad-ACE2 and Ad-EGFP groups) received an intratracheal injection of normal saline, Ad-ACE2 and Ad-EGFP, respectively. The normal group underwent the same procedure but received an intratracheal injection of normal saline only. Pulmonary function tests, lung histopathology analysis, malondialdehyde (MDA) and reactive oxygen species (ROS) level, ACE2 mRNA and protein expression level, inflammatory cytokines and related signaling pathway proteins were measured. RESULTS COPD rats showed impairment of lung function as evidenced by decreased ratio of forced expiratory volume at 0.3 s and forced vital capacity (FEV0.3/FVC) and dynamic lung compliance (Cldyn), increased resistance inspiration (Ri) and resistance expiration (Re) as compared with the normal group, accompanying with reduced ACE2 mRNA expression, elevated ROS and MDA, elevated inflammatory cytokines levels (tumor necrosis factor α, TNF-α; interleukin-8, IL-8; IL-2 and IL-1β) and activation of nuclear factor-κB (NF-κB) and p38 MAPK (mitogen activated protein kinases) pathway in lung tissues. ACE2 overexpression through Ad-ACE2 infusion significantly attenuated the inflammatory response in lung tissues of COPD model rats. CONCLUSION ACE2 could attenuate COPD inflammatory process induced by cigarette smoke through reduction of oxidative stress and inhibition of NF-κB and p38 MAPK pathway activation.
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Affiliation(s)
- Tian Xue
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University , Shanghai , China and
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227
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Wagenaar GTM, Sengers RMA, Laghmani EH, Chen X, Lindeboom MPHA, Roks AJM, Folkerts G, Walther FJ. Angiotensin II type 2 receptor ligand PD123319 attenuates hyperoxia-induced lung and heart injury at a low dose in newborn rats. Am J Physiol Lung Cell Mol Physiol 2014; 307:L261-72. [PMID: 24951776 DOI: 10.1152/ajplung.00345.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Intervening in angiotensin (Ang)-II type 2 receptor (AT2) signaling may have therapeutic potential for bronchopulmonary dysplasia (BPD) by attenuating lung inflammation and preventing arterial hypertension (PAH)-induced right ventricular hypertrophy (RVH). We first investigated the role of AT2 inhibition with PD123319 (0.5 and 2 mg·kg(-1)·day(-1)) on the beneficial effect of AT2 agonist LP2-3 (5 μg/kg twice a day) on RVH in newborn rats with hyperoxia-induced BPD. Next we determined the cardiopulmonary effects of PD123319 (0.1 mg·kg(-1)·day(-1)) in two models: early treatment during continuous exposure to hyperoxia for 10 days and late treatment starting on day 6 in rat pups exposed postnatally to hyperoxia for 9 days, followed by a 9-day recovery period in room air. Parameters investigated included lung and heart histopathology, fibrin deposition, vascular leakage, and differential mRNA expression. Ten days of coadministration of LP2-3 and PD123319 abolished the beneficial effects of LP2-3 on RVH in experimental BPD. In the early treatment model PD123319 attenuated cardiopulmonary injury by reducing alveolar septal thickness, pulmonary influx of inflammatory cells, including macrophages and neutrophils, medial wall thickness of small arterioles, and extravascular collagen III deposition, and by preventing RVH. In the late treatment model PD123319 diminished PAH and RVH, demonstrating that PAH is reversible in the neonatal period. At high concentrations PD123319 blocks the beneficial effects of the AT2-agonist LP2-3 on RVH. At low concentrations PD123319 attenuates cardiopulmonary injury by reducing pulmonary inflammation and fibrosis and preventing PAH-induced RVH but does not affect alveolar and vascular development in newborn rats with experimental BPD.
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Affiliation(s)
- Gerry T M Wagenaar
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands;
| | - Rozemarijn M A Sengers
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands
| | - El Houari Laghmani
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Xueyu Chen
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Melissa P H A Lindeboom
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Anton J M Roks
- Division of Vascular Disease and Pharmacology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Gert Folkerts
- Department of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; and
| | - Frans J Walther
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, The Netherlands; Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
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Hillman NH, Gisslen T, Polglase GR, Kallapur SG, Jobe AH. Ventilation-induced increases in EGFR ligand mRNA are not altered by intra-amniotic LPS or ureaplasma in preterm lambs. PLoS One 2014; 9:e96087. [PMID: 24788984 PMCID: PMC4005755 DOI: 10.1371/journal.pone.0096087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 04/02/2014] [Indexed: 11/18/2022] Open
Abstract
Chorioamnionitis and mechanical ventilation are associated with bronchopulmonary dysplasia (BPD) in preterm infants. Mechanical ventilation at birth activates both inflammatory and acute phase responses. These responses can be partially modulated by previous exposure to intra-amniotic (IA) LPS or Ureaplasma parvum (UP). Epidermal growth factor receptor (EGFR) ligands participate in lung development, and angiotensin converting enzyme (ACE) 1 and ACE2 contribute to lung inflammation. We asked whether brief mechanical ventilation at birth altered EGFR and ACE pathways and if antenatal exposure to IA LPS or UP could modulate these effects. Ewes were exposed to IA injections of UP, LPS or saline multiple days prior to preterm delivery at 85% gestation. Lambs were either immediately euthanized or mechanically ventilated for 2 to 3 hr. IA UP and LPS cause modest changes in the EGFR ligands amphiregulin (AREG), epiregulin (EREG), heparin binding epidermal growth factor (HB-EGF), and betacellulin (BTC) mRNA expression. Mechanical ventilation greatly increased mRNA expression of AREG, EREG, and HB-EGF, with no additional increases resulting from IA LPS or UP. With ventilation AREG and EREG mRNA localized to cells in terminal airspace. EGFR mRNA also increased with mechanical ventilation. IA UP and LPS decreased ACE1 mRNA and increased ACE2 mRNA, resulting in a 4 fold change in the ACE1/ACE2 ratio. Mechanical ventilation with large tidal volumes increased both ACE1 and ACE2 expression. The alterations seen in ACE with IA exposures and EGFR pathways with mechanical ventilation may contribute to the development of BPD in preterm infants.
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Affiliation(s)
- Noah H. Hillman
- Division of Neonatology, Saint Louis University, Saint Louis, Missouri, United States of America
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| | - Tate Gisslen
- Division of Neonatology, Saint Louis University, Saint Louis, Missouri, United States of America
| | - Graeme R. Polglase
- School of Women and Infants' Health, University of Western Australia Perth, WA, Australia
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, VIC, Australia
| | - Suhas G. Kallapur
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
- School of Women and Infants' Health, University of Western Australia Perth, WA, Australia
| | - Alan H. Jobe
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America
- School of Women and Infants' Health, University of Western Australia Perth, WA, Australia
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229
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Regenhardt RW, Bennion DM, Sumners C. Cerebroprotective action of angiotensin peptides in stroke. Clin Sci (Lond) 2014; 126:195-205. [PMID: 24102099 PMCID: PMC7453725 DOI: 10.1042/cs20130324] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The goal of the present review is to examine the evidence for beneficial actions of manipulation of the RAS (renin-angiotensin system) in stroke, with particular focus on Ang-(1-7) [angiotensin-(1-7)] and its receptor Mas. The RAS appears to be highly involved in the multifactorial pathophysiology of stroke. Blocking the effects of AngII (angiotensin II) at AT1R (AngII type 1 receptor), through the use of commonly prescribed ACE (angiotensin-converting enzyme) inhibitors or AT1R blockers, has been shown to have therapeutic effects in both ischaemic and haemorrhagic stroke. In contrast with the deleterious actions of over activation of AT1R by AngII, stimulation of AT2Rs (AngII type 2 receptors) in the brain has been demonstrated to elicit beneficial effects in stroke. Likewise, the ACE2/Ang-(1-7)/Mas axis of the RAS has been shown to have therapeutic effects in stroke when activated, countering the effects of the ACE/AngII/AT1R axis. Studies have demonstrated that activating this axis in the brain elicits beneficial cerebral effects in rat models of ischaemic stroke, and we have also demonstrated the cerebroprotective potential of this axis in haemorrhagic stroke using stroke-prone spontaneously hypertensive rats and collagenase-induced striatal haemorrhage. The mechanism of cerebroprotection elicited by ACE2/Ang-(1-7)/Mas activation includes anti-inflammatory effects within the brain parenchyma. The major hurdle to overcome in translating these results to humans is devising strategies to activate the ACE2/Ang-(1-7)/Mas cerebroprotective axis using post-stroke treatments that can be administered non-invasively.
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Affiliation(s)
- Robert W. Regenhardt
- Department of Physiology and Functional Genomics & McKnight Brain Institute, University of Florida, 1600 SW Archer Road, PO Box 100274, Gainesville, FL 32610-0274, USA
| | - Douglas M. Bennion
- Department of Physiology and Functional Genomics & McKnight Brain Institute, University of Florida, 1600 SW Archer Road, PO Box 100274, Gainesville, FL 32610-0274, USA
| | - Colin Sumners
- Department of Physiology and Functional Genomics & McKnight Brain Institute, University of Florida, 1600 SW Archer Road, PO Box 100274, Gainesville, FL 32610-0274, USA
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230
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Abstract
Septic shock results from the dysregulation of the innate immune response following infection. Despite major advances in fundamental and clinical research, patients diagnosed with septic shock still have a poor prognostic outcome, with a mortality rate of up to 50%. Indeed, the reasons leading to septic shock are still poorly understood. First postulated 30 years ago, the general view of septic shock as an acute and overwhelming inflammatory response still prevails today. Recently, the fact that numerous clinical trials have failed to demonstrate any positive medical outcomes has caused us to question our fundamental understanding of this condition. New and sophisticated technologies now allow us to accurately profile the various stages and contributory components of the inflammatory response defining septic shock, and many studies now report a more complex inflammatory response, particularly during the early phase of sepsis. In addition, novel experimental approaches, using more clinically relevant animal models, to standardize and stratify research outcomes are now being argued for. In the present review, we discuss the most recent findings in relation to our understanding of the underlying mechanisms involved in septic shock, and highlight the attempts made to improve animal experimental models. We also review recent studies reporting promising results with two vastly different therapeutic approaches influencing the renin-angiotensin system and applying mesenchymal stem cells for clinical intervention.
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231
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Dysregulated Renin-AngioteNsin System Contributes to acute Lung Injury Caused by Hind-limb Ischemia-Reperfusion in Mice. Shock 2013; 40:420-9. [DOI: 10.1097/shk.0b013e3182a6953e] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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232
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Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome. Pediatr Crit Care Med 2013; 14:e438-41. [PMID: 24226567 DOI: 10.1097/pcc.0b013e3182a55735] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts angiotensin II into angiotensin-(1-7). The aim of this study was to determine pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in patients with acute respiratory distress syndrome. DESIGN Prospective observational pilot study. SETTING A PICU of a university hospital. PATIENTS Fourteen patients admitted, requiring mechanical ventilation for respiratory syncytial virus lower respiratory tract infection. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Two groups of patients were distinguished at admission: a group fulfilling the criteria for acute respiratory distress syndrome and a non-acute respiratory distress syndrome group. Angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity were measured in bronchoalveolar lavage fluid. Patients with acute respiratory distress syndrome had increased angiotensin-converting enzyme activity and decreased angiotensin-converting enzyme 2 activity (p < 0.001) compared with the control group. CONCLUSION It is shown for the first time that in acute respiratory distress syndrome, enhanced angiotensin-converting enzyme activity is paralleled by a reduced angiotensin-converting enzyme 2 activity, similar to that found in an experimental rat model of acute respiratory distress syndrome. The reduced angiotensin-converting enzyme 2 activity may be counteracted by restoring angiotensin-(1-7) level, thereby offering a novel treatment modality for this syndrome.
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233
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Abstract
The field of anatomic pathology has changed significantly over the last decades and, as a result of the technological developments in molecular pathology and genetics, has had increasing pressures put on it to become quantitative and to provide more information about protein expression on a cellular level in tissue sections. Multispectral imaging (MSI) has a long history as an advanced imaging modality and has been used for over a decade now in pathology to improve quantitative accuracy, enable the analysis of multicolor immunohistochemistry, and drastically reduce the impact of contrast-robbing tissue autofluorescence common in formalin-fixed, paraffin-embedded tissues. When combined with advanced software for the automated segmentation of different tissue morphologies (eg, tumor vs stroma) and cellular and subcellular segmentation, MSI can enable the per-cell quantitation of many markers simultaneously. This article covers the role that MSI has played in anatomic pathology in the analysis of formalin-fixed, paraffin-embedded tissue sections, discusses the technological aspects of why MSI has been adopted, and provides a review of the literature of the application of MSI in anatomic pathology.
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234
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Meyer NJ. Future clinical applications of genomics for acute respiratory distress syndrome. THE LANCET RESPIRATORY MEDICINE 2013; 1:793-803. [PMID: 24461759 DOI: 10.1016/s2213-2600(13)70134-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Acute respiratory distress syndrome remains a substantial cause of morbidity and mortality in intensive care units, yet no specific pharmacotherapy has proven useful in reducing the duration of mechanical ventilation or improving survival. One factor that might hamper the development of treatment for acute respiratory distress syndrome is the heterogeneous nature of the population who present with the syndrome. In this Review, the potential of genomic approaches-genetic association, gene expression, metabolomic, proteomic, and systems biology applications-for the identification of molecular endotypes within acute respiratory distress syndrome and potentially for the prediction, diagnosis, prognosis, and treatment of this difficult disorder are discussed.
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Affiliation(s)
- Nuala J Meyer
- Department of Medicine Pulmonary, Allergy, and Critical Care Division, University of Pennsylvania, Philadelphia, PA, USA.
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235
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Hendrickson CM, Matthay MA. Viral pathogens and acute lung injury: investigations inspired by the SARS epidemic and the 2009 H1N1 influenza pandemic. Semin Respir Crit Care Med 2013; 34:475-86. [PMID: 23934716 PMCID: PMC4045622 DOI: 10.1055/s-0033-1351122] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Acute viral pneumonia is an important cause of acute lung injury (ALI), although not enough is known about the exact incidence of viral infection in ALI. Polymerase chain reaction-based assays, direct fluorescent antigen (DFA) assays, and viral cultures can detect viruses in samples from the human respiratory tract, but the presence of the virus does not prove it to be a pathogen, nor does it give information regarding the interaction of viruses with the host immune response and bacterial flora of the respiratory tract. The severe acute respiratory syndrome (SARS) epidemic and the 2009 H1N1 influenza pandemic provided a better understanding of how viral pathogens mediate lung injury. Although the viruses initially infect the respiratory epithelium, the relative role of epithelial damage and endothelial dysfunction has not been well defined. The inflammatory host immune response to H1N1 infection is a major contributor to lung injury. The SARS coronavirus causes lung injury and inflammation in part through actions on the nonclassical renin angiotensin pathway. The lessons learned from the pandemic outbreaks of SARS coronavirus and H1N1 capture key principles of virally mediated ALI. There are pathogen-specific pathways underlying virally mediated ALI that converge onto a common end pathway resulting in diffuse alveolar damage. In terms of therapy, lung protective ventilation is the cornerstone of supportive care. There is little evidence that corticosteroids are beneficial, and they might be harmful. Future therapeutic strategies may be targeted to specific pathogens, the pathogenetic pathways in the host immune response, or enhancing repair and regeneration of tissue damage.
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Affiliation(s)
- Carolyn M Hendrickson
- Division of Pulmonary and Critical Care Medicine, Departments of Medicine and Anesthesia, Cardiovascular Research Institute, University of California-San Francisco, CA 94143, USA
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236
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Chen Q, Yang Y, Huang Y, Pan C, Liu L, Qiu H. Angiotensin-(1-7) attenuates lung fibrosis by way of Mas receptor in acute lung injury. J Surg Res 2013; 185:740-7. [PMID: 23890397 DOI: 10.1016/j.jss.2013.06.052] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/15/2013] [Accepted: 06/20/2013] [Indexed: 01/03/2023]
Abstract
BACKGROUND Pulmonary fibrosis occurs in approximately 60% of patients with acute respiratory distress syndrome and has been significantly correlated with a poor outcome. The overexpression of angiotensin (Ang) II can induce lung inflammation and fibrosis. This observation, coupled with the knowledge that Ang-(1-7) is considered to be an endogenous antagonist of Ang II, led us to hypothesize that Ang-(1-7) would prevent lung remodeling in patients with acute respiratory distress syndrome. MATERIALS AND METHODS The protocol involved five groups: (1) control, (2) lipopolysaccharide (LPS), (3) losartan as a positive control group, (4) Ang-(1-7), and (5) [D-Ala7]-Ang-(1-7) (A779), an antagonist of the Ang-(1-7) receptor. Acute lung injury was induced by an intratracheal injection of LPS 5 mg/kg in C57BL/6 mice. Losartan (10 mg/kg) was administered by gavage daily, starting from 1 d before LPS stimulation. Ang-(1-7) or A779 in saline (100 ng/kg/min) was infused subcutaneously 1 h before acute lung injury induction for 3 or 7 d. The lung tissues were harvested for analysis at day 3 or 7 after injection of LPS. RESULTS LPS stimulation resulted in significantly increased inflammation, edema, and lung collagen production. With Ang-(1-7) treatment, the lung fibrosis score and hydroxyproline level were significantly reduced, and the expression of transforming growth factor-β and Smad2/3 were decreased on days 3 and 7. Losartan attenuated lung fibrosis similarly to Ang-(1-7) after LPS exposure. In the A779 group, a tendency was seen to aggravate collagen deposition and lung remodeling. CONCLUSIONS These findings indicate an antiremodeling role for Ang-(1-7) in acute lung injury, similar to the blocker of Ang II receptor, that might be at least partially mediated through an Ang-(1-7) receptor.
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Affiliation(s)
- Qiuhua Chen
- Department of Critical Care Medicine, Nanjing Zhong-Da Hospital, Southeast University School of Medicine, Nanjing, People's Republic of China
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237
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Wagenaar GTM, Laghmani EH, Fidder M, Sengers RMA, de Visser YP, de Vries L, Rink R, Roks AJM, Folkerts G, Walther FJ. Agonists of MAS oncogene and angiotensin II type 2 receptors attenuate cardiopulmonary disease in rats with neonatal hyperoxia-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2013; 305:L341-51. [PMID: 23812633 DOI: 10.1152/ajplung.00360.2012] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Stimulation of MAS oncogene receptor (MAS) or angiotensin (Ang) receptor type 2 (AT2) may be novel therapeutic options for neonatal chronic lung disease (CLD) by counterbalancing the adverse effects of the potent vasoconstrictor angiotensin II, consisting of arterial hypertension (PAH)-induced right ventricular hypertrophy (RVH) and pulmonary inflammation. We determined the cardiopulmonary effects in neonatal rats with CLD of daily treatment during continuous exposure to 100% oxygen for 10 days with specific ligands for MAS [cyclic Ang-(1-7); 10-50 μg·kg(-1)·day(-1)] and AT2 [dKcAng-(1-7); 5-20 μg·kg(-1)·day(-1)]. Parameters investigated included lung and heart histopathology, fibrin deposition, vascular leakage, and differential mRNA expression in the lungs of key genes involved in the renin-angiotensin system, inflammation, coagulation, and alveolar development. We investigated the role of nitric oxide synthase inhibition with N(ω)-nitro-l-arginine methyl ester (25 mg·kg(-1)·day(-1)) during AT2 agonist treatment. Prophylactic treatment with agonists for MAS or AT2 for 10 days diminished cardiopulmonary injury by reducing alveolar septum thickness and medial wall thickness of small arterioles and preventing RVH. Both agonists attenuated the pulmonary influx of inflammatory cells, including macrophages (via AT2) and neutrophils (via MAS) but did not reduce alveolar enlargement and vascular alveolar leakage. The AT2 agonist attenuated hyperoxia-induced fibrin deposition. In conclusion, stimulation of MAS or AT2 attenuates cardiopulmonary injury by reducing pulmonary inflammation and preventing PAH-induced RVH but does not affect alveolar and vascular development in neonatal rats with experimental CLD. The beneficial effects of AT2 activation on experimental CLD were mediated via a NOS-independent mechanism.
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Affiliation(s)
- Gerry T M Wagenaar
- Department of Pediatrics, Division of Neonatology, Leiden University Medical Center, Leiden, the Netherlands.
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238
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The effect of endogenous angiotensin II on alveolar fluid clearance in rats with acute lung injury. Can Respir J 2013; 19:311-8. [PMID: 23061076 DOI: 10.1155/2012/951025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND In acute lung injury (ALI), angiotensin II (Ang II) plays a vital role in the stimulation of pulmonary permeability edema formation through the angiotensin type 1 (AT1) receptor. The effect of Ang II on alveolar fluid clearance (AFC) in ALI remains unknown. METHODS Sprague Dawley rats were anesthetized and intratracheally injected with 1 mg⁄kg lipopolysaccharide (LPS), while control rats received saline. The AT1 receptor antagonist ZD7155 was injected intraperitoneally (10 mg⁄kg) 30 min before LPS administration. The lungs were isolated for AFC measurement, and alpha-epithelial sodium channel (ENaC) messenger RNA and protein expression were detected by reverse-transcription polymerase chain reaction and Western blot. RESULTS LPS-induced ALI caused an increase in Ang II levels in plasma and lung tissue but a decrease in AFC. The time course of Ang II levels paralleled that of AFC. Pretreatment with ZD7155 prevented ALI-induced reduction of AFC. ZD7155 also reversed the ALI-induced reduction of beta-ENaC and gamma-ENaC levels, and further decreased alpha-ENaC levels. CONCLUSIONS These findings suggest that endogenous Ang II inhibits AFC and dysregulates ENaC expression via AT1 receptors, which contribute to alveolar filling and pulmonary edema in LPS-induced ALI.
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Abstract
It is well known that the RAS (renin-angiotensin system) plays a key role in the modulation of many functions in the body. AngII (angiotensin II) acting on AT1R (type 1 AngII receptor) has a central role in mediating most of the actions of the RAS. However, over the past 10 years, several studies have presented evidence for the existence of a new arm of the RAS, namely the ACE (angiotensin-converting enzyme) 2/Ang-(1-7) [angiotensin-(1-7)]/Mas axis. Ang-(1-7) can be produced from AngI or AngII via endo- or carboxy-peptidases respectively. ACE2 appears to play a central role in Ang-(1-7) formation. As described for AngII, Ang-(1-7) also has a broad range of effects in different organs and tissues which goes beyond its initially described cardiovascular and renal actions. Those effects are mediated by Mas and can counter-regulate most of the deleterious effects of AngII. The interaction Ang-(1-7)/Mas regulates different signalling pathways, such as PI3K (phosphoinositide 3-kinase)/AKT and ERK (extracellularsignal-regulated kinase) pathways and involves downstream effectors such as NO, FOXO1 (forkhead box O1) and COX-2 (cyclo-oxygenase-2). Through these mechanisms, Ang-(1-7) is able to improve pathological conditions including fibrosis and inflammation in organs such as lungs, liver and kidney. In addition, this heptapeptide has positive effects on metabolism, increasing the glucose uptake and lipolysis while decreasing insulin resistance and dyslipidaemia. Ang-(1-7) is also able to improve cerebroprotection against ischaemic stroke, besides its effects on learning and memory. The reproductive system can also be affected by Ang-(1-7) treatment, with enhanced ovulation, spermatogenesis and sexual steroids synthesis. Finally, Ang-(1-7) is considered a potential anti-cancer treatment since it is able to inhibit cell proliferation and angiogenesis. Thus the ACE2/Ang-(1-7)/Mas pathway seems to be involved in many physiological and pathophysiological processes in several systems and organs especially by opposing the detrimental effects of inappropriate overactivation of the ACE/AngII/AT1R axis.
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Liao K, Sikkema D, Wang C, Lee TN. Development of an enzymatic assay for the detection of neutralizing antibodies against therapeutic angiotensin-converting enzyme 2 (ACE2). J Immunol Methods 2013; 389:52-60. [PMID: 23298658 DOI: 10.1016/j.jim.2012.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 12/06/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
Abstract
Therapeutic proteins have the potential to elicit immune responses in animals and humans (Mire-Sluis et al., 2004; Yu et al., 2006; Shankar et al., 2008). Contributors to the response could include product related factors such as chemical modifications, impurities that co-purify with product, contaminants, formulation, aggregates, and clinical factors such as dose concentration, dosing frequency, route of drug administration, rate of administration, patient underlying disease, concomitant medication, and genetic status among others (Patten and Schellekens, 2003). Further, an immune response triggered by a therapeutic enzyme may neutralize the endogenous counterpart resulting in a decrease or depletion of the therapeutic and endogenous enzymes imposing safety concerns for patients. Therefore, monitoring of anti-drug antibody (ADA) and neutralizing antibody (NAb) responses to both the recombinant therapeutic enzyme and endogenous enzyme is important during early development and subsequent clinical studies. Testing considerations for NAb detection against therapeutic enzymes have been published mostly for lysosomal storage diseases (Wang et al., 2008). NAb cross-reactivity to the endogenous counterpart has also been characterized (Sominanda et al., 2010). Here, we describe an enzymatic NAb assay which detects neutralizing antibodies to both recombinant and endogenous angiotensin-converting enzyme 2 (ACE2). NAb assay sensitivity was optimized by selecting the assay incubation time as 20 min with an enzyme concentration of 0.5 μg/mL. Four anti-ACE2 antibodies out of a commercial panel of 18 were found to have neutralizing capabilities based upon their ability to abrogate ACE2 enzymatic activity. We demonstrated assay specificity by small peptide inhibitors specific for ACE or ACE2. DX600, an ACE2 specific inhibitor did not cross-react with ACE. Conversely, captopril, an inhibitor of ACE did not inhibit ACE2. The assay specificity for ACE2 neutralizing antibodies was further demonstrated by the lack of reactivity of two species control antibodies and 14 anti-ACE2 antibodies. Moreover, we demonstrated assay specificity to human endogenous ACE2 from human epithelial cells. Three human cell lines (Calu-3, Caco-2, Huh-7) were evaluated for the cell surface expression of ACE2 by flow cytometry and Western blot. Subsequently, whole cell lysates, cell culture supernatant, and live cells were evaluated in the assay. Results demonstrated that Calu-3 had elevated levels of ACE2 compared to Caco-2 or Huh-7. Calu-3 also demonstrated elevated ACE2 enzymatic activity in all three sources and could be inhibited by the ACE2 specific inhibitor DX600 as well as the neutralizing antibodies for the recombinant ACE2. Thus, we describe here a method to detect NAb against a therapeutic enzyme and assess NAb cross-reactivity to the native endogenous enzyme. The approach of method development described here could be applied for the assessment of NAb responses to other enzymatic therapeutics.
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Affiliation(s)
- Karen Liao
- Clinical Immunology, GlaxoSmithKline, King Of Prussia, PA 19406, United States
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Abstract
Modulation of the RAS (renin–angiotensin system), in particular of the function of the hormones AngII (angiotensin II) and Ang-(1–7) [angiotensin-(1–7)], is an important target for pharmacotherapy in the cardiovascular system. In the classical view, such modulation affects cardiovascular cells to decrease hypertrophy, fibrosis and endothelial dysfunction, and improves diuresis. In this view, excessive stimulation of AT1 receptors (AngII type 1 receptors) fulfils a detrimental role, as it promotes cardiovascular pathogenesis, and this is opposed by stimulation of the AT2 receptor (angiotensin II type 2 receptor) and the Ang-(1–7) receptor encoded by the Mas proto-oncogene. In recent years, this view has been broadened with the observation that the RAS regulates bone marrow stromal cells and stem cells, thus involving haematopoiesis and tissue regeneration by progenitor cells. This change of paradigm has enlarged the field of perspectives for therapeutic application of existing as well as newly developed medicines that alter angiotensin signalling, which now stretches beyond cardiovascular therapy. In the present article, we review the role of AngII and Ang-(1–7) and their respective receptors in haematopoietic and mesenchymal stem cells, and discuss possible pharmacotherapeutical implications.
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