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Lenz MR, Tsai SY, Roessler AE, Wang Y, Sethupathi P, Jones WK, Kartje GL, Simmons WH. A Potent Inhibitor of Aminopeptidase P2 Reduces Reperfusion Injury in Models of Myocardial Infarction and Stroke. J Pharmacol Exp Ther 2022; 380:220-229. [PMID: 34980660 PMCID: PMC11046727 DOI: 10.1124/jpet.121.000875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/28/2021] [Indexed: 11/22/2022] Open
Abstract
During a myocardial infarction or ischemic stroke, blood flow to the heart or brain is partially blocked. This results in reduced delivery of oxygen and nutrients and, ultimately, tissue damage. Initial treatment involves removing the clot and restoring blood flow (reperfusion). However, this treatment is not as effective as one would hope because the reperfusion process itself can cause a different type of damage (reperfusion injury) that contributes up to 50% of the total damage. Bradykinin is an autocoid that is released from blood vessel endothelial cells during ischemia and reperfusion and has the potential to prevent reperfusion injury. However, bradykinin is rapidly inactivated by enzymes on endothelial cells, limiting its beneficial effects. One of these enzymes is aminopeptidase P2. We designed a potent and specific inhibitor of aminopeptidase P2 called ST-115, [(S)-2-mercapto-4-methylpentanoyl]-4(S)-fluoro-Pro-Pro-3(R)-beta-Pro. When ST-115 is administered intravenously at the start of reperfusion, it reduces bradykinin degradation. This increases bradykinin's concentration in the capillaries and enhances its protective effects. We tested ST-115 in a mouse model of myocardial infarction and found that the damaged area of the heart was reduced by 58% compared with mice given saline. In a rat model of ischemic stroke, ST-115 reduced functional deficits in a skilled walking test by 60% and reduced brain edema by 51%. It reduced brain infarct size by 48% in a major subset of rats with small strokes. The results indicate that ST-115 can ameliorate reperfusion injury and can ultimately serve as a therapeutic for acute myocardial infarction and ischemic stroke. SIGNIFICANCE STATEMENT: We have shown that our aminopeptidase P2 inhibitor, ST-115, can reduce tissue injury caused by episodes of ischemia followed by reperfusion. It was successful in rodent models of myocardial infarction and stroke. The clinical use would involve the intravenous administration of ST-115 at the induction of reperfusion. In the case of stroke, the successful technique of thrombectomy could be combined with ST-115 administration to simultaneously reduce both ischemic and reperfusion injury.
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Affiliation(s)
- Morgan R Lenz
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - Shih-Yen Tsai
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - Anne E Roessler
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - Yang Wang
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - Periannan Sethupathi
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - W Keith Jones
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - Gwendolyn L Kartje
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
| | - William H Simmons
- Department of Molecular Pharmacology and Neuroscience, Stritch School of Medicine Health Sciences Division, Loyola University Chicago, Maywood, Illinois (M.R.L., A.E.R., Y.W., P.S., W.K.J., G.L.K., W.H.S.) and Research Service, Edwards Hines Jr. VA Hospital, Hines, Illinois (S.-Y.T., G.L.K.)
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Chang HC, Kung CCH, Chang TT, Jao SC, Hsu YT, Li WS. Investigation of the proton relay system operative in human cystosolic aminopeptidase P. PLoS One 2018; 13:e0190816. [PMID: 29351301 PMCID: PMC5774706 DOI: 10.1371/journal.pone.0190816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/20/2017] [Indexed: 11/19/2022] Open
Abstract
Aminopeptidase P, a metalloprotease, targets Xaa-Proline peptides for cleavage [1-4]. There are two forms of human AMPP, a membrane-bound form (hmAMPP) and a soluble cytosolic form (hcAMPP)[5]. Similar to the angiotensin-I-converting enzyme, AMPP plays an important role in the catabolism of inflammatory and vasoactive peptides, known as kinins. The plasma kinin, bradykinin, was used as the substrate to conduct enzymatic activity analyses and to determine the Michaelis constant (Km) of 174 μM and the catalytic rate constant (kcat) of 10.8 s-1 for hcAMPP. Significant differences were observed in the activities of Y527F and R535A hcAMPP mutants, which displayed a 6-fold and 13.5-fold for decrease in turnover rate, respectively. Guanidine hydrochloride restored the activity of R535A hcAMPP, increasing the kcat/Km 20-fold, yet it had no impact on the activities of the wild-type or Y527F mutant hcAMPPs. Activity restoration by guanidine derivatives followed the order guanidine hydrochloride >> methyl-guanidine > amino-guanidine > N-ethyl-guanidine. Overall, the results indicate the participation of R535 in the hydrogen bond network that forms a proton relay system. The quaternary structure of hcAMPP was determined by using analytical ultracentrifugation (AUC). The results show that alanine replacement of Arg535 destabilizes the hcAMPP dimer and that guanidine hydrochloride restores the native monomer-dimer equilibrium. It is proposed that Arg535 plays an important role in hcAMMP catalysis and in stabilization of the catalytically active dimeric state.
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Affiliation(s)
| | | | | | - Shu-Chuan Jao
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Ting Hsu
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Wen-Shan Li
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan
- * E-mail:
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Singh RB, Dandekar SP, Elimban V, Gupta SK, Dhalla NS. Role of proteases in the pathophysiology of cardiac disease. Mol Cell Biochem 2016; 263:241-56. [PMID: 27520682 DOI: 10.1023/b:mcbi.0000041865.63445.40] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cardiovascular disease is a major cause of death and thus a great deal of effort has been made in salvaging the diseased myocardium. Although various factors have been identified as possible causes of different cardiac diseases such as heart failure and ischemic heart disease, there is a real need to elucidate their role for the better understanding of the cardiac disease pathology and formulation of strategies for developing newer therapeutic interventions. In view of the intimate involvement of different types of proteases in maintaining cellular structure, the role of proteases in various cardiac diseases has become the focus of recent research. Proteases are present in the cytosol as well as are localized in a number of subcellular organelles in the cell. These are known to use extracellular matrix, cytoskeletal, sarcolemmal, sarcoplasmic reticular, mitochondrial and myofibrillar proteins as substrates. Work from different laboratories using a wide variety of techniques has shown that the activation of proteases causes alterations of a number of specific proteins leading to subcellular remodeling and cardiac dysfunction. Inhibition of protease action by different drugs and agents, therefore, has a clinical relevance and is expected to form a part of new treatment paradigm for improving heart function. This review examines the biochemistry and localization of some of the proteases in the cardiac tissue in addition to identification of the sites of action of some protease inhibitors. (Mol Cell Biochem 263: 241-256, 2004).
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Affiliation(s)
- Raja B Singh
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6
| | - Sucheta P Dandekar
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6
| | - Vijayan Elimban
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6
| | - Suresh K Gupta
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6
| | - Naranjan S Dhalla
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6
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Iyer S, La-Borde PJ, Payne KAP, Parsons MR, Turner AJ, Isaac RE, Acharya KR. Crystal structure of X-prolyl aminopeptidase from Caenorhabditis elegans: A cytosolic enzyme with a di-nuclear active site. FEBS Open Bio 2015; 5:292-302. [PMID: 25905034 PMCID: PMC4404410 DOI: 10.1016/j.fob.2015.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 01/22/2023] Open
Abstract
Eukaryotic aminopeptidase P1 (APP1), also known as X‐prolyl aminopeptidase (XPNPEP1) in human tissues, is a cytosolic exopeptidase that preferentially removes amino acids from the N‐terminus of peptides possessing a penultimate N‐terminal proline residue. The enzyme has an important role in the catabolism of proline containing peptides since peptide bonds adjacent to the imino acid proline are resistant to cleavage by most peptidases. We show that recombinant and catalytically activeCaenorhabditis elegans APP‐1 is a dimer that uses dinuclear zinc at the active site and, for the first time, we provide structural information for a eukaryotic APP‐1 in complex with the inhibitor, apstatin. Our analysis reveals thatC. elegans APP‐1 shares similar mode of substrate binding and a common catalytic mechanism with other known X‐prolyl aminopeptidases. We present the crystal structure ofC. elegans APP‐1 both in bound and unbound forms. We showC. elegans APP‐1 uses dinuclear zinc at the active site. We confirm thatC. elegans APP‐1 is biological dimer. Our analysis reveals thatC. elegans APP‐1 shares a common catalytic mechanism with other X‐prolyl aminopeptidases.
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Key Words
- APP1, aminopeptidase P1
- Apstatin
- CCP4, computational collaborative project 4
- Di-nuclear active site
- ICP-AES, inductively coupled plasma atomic emission spectroscopy
- ICP-MS, inductively coupled plasma mass spectrometry
- MAP, methionine aminopeptidase
- NMR, nuclear magnetic resonance
- PCR, polymerase chain reaction
- PEG3350, polyethylene glycol 3350
- Protease inhibitor
- X-prolyl aminopeptidase
- X-ray crystallography
- XPNPEP, X-prolyl aminopeptidase
- Zinc metalloprotease
- rmsd, root mean square deviation
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Affiliation(s)
- Shalini Iyer
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Penelope J La-Borde
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK ; School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Karl A P Payne
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Faculty of Life Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Mark R Parsons
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK ; Sevenoaks School, Sevenoaks TN13 1HU, UK
| | - Anthony J Turner
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - R Elwyn Isaac
- Faculty of Biological Sciences, Clarendon Way, University of Leeds, Leeds LS2 9JT, UK
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
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Gao Y, Hao J, Zhang H, Qian G, Jiang R, Hu J, Wang J, Lei Z, Zhao G. Protective effect of the combinations of glycyrrhizic, ferulic and cinnamic acid pretreatment on myocardial ischemia-reperfusion injury in rats. Exp Ther Med 2014; 9:435-445. [PMID: 25574212 PMCID: PMC4280987 DOI: 10.3892/etm.2014.2134] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 08/01/2014] [Indexed: 12/11/2022] Open
Abstract
The aim of this study was to find an effective drug cocktail pretreatment to protect myocardial tissue of the heart from ischemia-reperfusion (I/R) injury. The mechanisms underlying the effects of the drug cocktail were subsequently explored in order to expand the application of Dang-gui-si-ni-tang (DGSN), a Traditional Chinese Medicine. The active components of DGSN in the serum following oral administration were investigated using high-performance liquid chromatography. The activity of superoxide dismutase (SOD) and malondialdehyde (MDA) levels were then analyzed to show the effect of the active components in the treatment of myocardial I/R injury. An L16 (44) orthogonal experiment was utilized to determine the most effective cocktail mix and the mechanism underlying the effect of this mix on myocardial I/R injury was investigated. It was observed that FCG, a mixture of glycyrrhizic (50 mg/kg), cinnamic (200 mg/kg) and ferulic (300 mg/kg) acid, was the optimal drug cocktail present in DGSN. This was absorbed into the blood following oral administration and was shown to decrease MDA levels and increase the activity of SOD. In conclusion, the findings suggest that FCG, a combination of active ingredients in the DGSN decoction, can be absorbed into the blood and protect the myocardium from I/R injury.
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Affiliation(s)
- Yuqin Gao
- Department of Cardiology, Ninth Affiliated Hospital of the Medical College of Xi'an Jiaotong University and Railway Central Hospital of Xi'an, Xi'an, Shanxi 710054, P.R. China ; College of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Jiping Hao
- Department of Cardiology, Ninth Affiliated Hospital of the Medical College of Xi'an Jiaotong University and Railway Central Hospital of Xi'an, Xi'an, Shanxi 710054, P.R. China
| | - Hongkao Zhang
- Department of Nursing Science, Huanghuai University, Zhumadian, Henan 463000, P.R. China
| | - Guoqiang Qian
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Renwang Jiang
- Department of Cardiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Jing Hu
- College of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
| | - Jianing Wang
- Department of Cardiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Zhang Lei
- Department of Cardiology, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, P.R. China
| | - Guoping Zhao
- College of Medicine, Jinan University, Guangzhou, Guangdong 510632, P.R. China
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Müller AL, Hryshko LV, Dhalla NS. Extracellular and intracellular proteases in cardiac dysfunction due to ischemia-reperfusion injury. Int J Cardiol 2012; 164:39-47. [PMID: 22357424 DOI: 10.1016/j.ijcard.2012.01.103] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 10/19/2011] [Accepted: 01/28/2012] [Indexed: 12/20/2022]
Abstract
Various procedures such as angioplasty, thrombolytic therapy, coronary bypass surgery, and cardiac transplantation are invariably associated with ischemia-reperfusion (I/R) injury. Impaired recovery of cardiac function due to I/R injury is considered to be a consequence of the occurrence of both oxidative stress and intracellular Ca(2+)-overload in the myocardium. These changes in the ischemic myocardium appear to activate both extracellular and intracellular proteases which are responsible for the cleavage of extracellular matrix and subcellular structures involved in the maintenance of cardiac function. It is thus intended to discuss the actions of I/R injury on several proteases, with a focus on calpain, matrix metalloproteinases, and cathepsins as well as their role in inducing alterations both inside and outside the cardiomyocytes. In addition, modifications of subcellular organelles such as myofibrils, sarcoplasmic reticulum and sarcolemma as well as extracellular matrix, and the potential regulatory effects of endogenous inhibitors on protease activities are identified. Both extracellular and intracellular proteolytic activities appear to be imperative in determining the true extent of I/R injury and their inhibition seems to be of critical importance for improving the recovery of cardiac function. Thus, both extracellular and intracellular proteases may serve as potential targets for the development of cardioprotective interventions for reducing damage to the heart and retarding the development of contractile dysfunction caused by I/R injury.
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Affiliation(s)
- Alison L Müller
- Institute of Cardiovascular Sciences, St Boniface Hospital Research Centre, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
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7
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Effects of des-aspartate-angiotensin I on myocardial ischemia-reperfusion injury in rats. Eur J Pharmacol 2011; 658:193-9. [DOI: 10.1016/j.ejphar.2011.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 01/25/2011] [Accepted: 02/17/2011] [Indexed: 11/18/2022]
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8
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Chen P, Dendorfer A, Finol-Urdaneta RK, Terlau H, Olivera BM. Biochemical characterization of kappaM-RIIIJ, a Kv1.2 channel blocker: evaluation of cardioprotective effects of kappaM-conotoxins. J Biol Chem 2010; 285:14882-14889. [PMID: 20220134 DOI: 10.1074/jbc.m109.068486] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Conus snail (Conus) venoms are a valuable source of pharmacologically active compounds; some of the peptide toxin families from the snail venoms are known to interact with potassium channels. We report the purification, synthesis, and characterization of kappaM-conotoxin RIIIJ from the venom of a fish-hunting species, Conus radiatus. This conopeptide, like a previously characterized peptide in the same family, kappaM-RIIIK, inhibits the homotetrameric human Kv1.2 channels. When tested in Xenopus oocytes, kappaM-RIIIJ has an order of magnitude higher affinity (IC(50) = 33 nm) to Kv1.2 than kappaM-RIIIK (IC(50) = 352 nm). Chimeras of RIIIK and RIIIJ tested on the human Kv1.2 channels revealed that Lys-9 from kappaM-RIIIJ is a determinant of its higher potency against hKv1.2. However, when compared in a model of ischemia/reperfusion, kappaM-RIIIK (100 mug/kg of body weight), administered just before reperfusion, significantly reduces the infarct size in rat hearts in vivo without influencing hemodynamics, providing a potential compound for cardioprotective therapeutics. In contrast, kappaM-RIIIJ does not exert any detectable cardioprotective effect. kappaM-RIIIJ shows more potency for Kv1.2-Kv1.5 and Kv1.2-Kv1.6 heterodimers than kappaM-RIIIK, whereas the affinity of kappaM-RIIIK to Kv1.2-Kv1.7 heterodimeric channels is higher (IC(50) = 680 nm) than that of kappaM-RIIIJ (IC(50) = 3.15 mum). Thus, the cardioprotection seems to correlate to antagonism to heteromultimeric channels, involving the Kv1.2 alpha-subunit rather than antagonism to Kv1.2 homotetramers. Furthermore, kappaM-RIIIK and kappaM-RIIIJ provide a valuable set of probes for understanding the underlying mechanism of cardioprotection.
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Affiliation(s)
- Ping Chen
- Department of Biology, University of Utah, Salt Lake City, Utah 84112
| | - Andreas Dendorfer
- Institute for Experimental and Clinical Pharmacology and Toxicology, Universitaetsklinikum Schleswig-Holstein, D-23538 Luebeck, Germany
| | - Rocio K Finol-Urdaneta
- Department of Physiology and Pharmacology and the Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada; Institute of Physiology, Christian-Albrechts-University Kiel, Olshausenstrasse 40, 24098 Kiel, Germany
| | - Heinrich Terlau
- Institute for Experimental and Clinical Pharmacology and Toxicology, Universitaetsklinikum Schleswig-Holstein, D-23538 Luebeck, Germany; Institute of Physiology, Christian-Albrechts-University Kiel, Olshausenstrasse 40, 24098 Kiel, Germany.
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Vögtle FN, Wortelkamp S, Zahedi RP, Becker D, Leidhold C, Gevaert K, Kellermann J, Voos W, Sickmann A, Pfanner N, Meisinger C. Global analysis of the mitochondrial N-proteome identifies a processing peptidase critical for protein stability. Cell 2009; 139:428-39. [PMID: 19837041 DOI: 10.1016/j.cell.2009.07.045] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/14/2009] [Accepted: 07/24/2009] [Indexed: 11/17/2022]
Abstract
Many mitochondrial proteins are synthesized with N-terminal presequences that are removed by specific peptidases. The N-termini of the mature proteins and thus peptidase cleavage sites have only been determined for a small fraction of mitochondrial proteins and yielded a controversial situation for the cleavage site specificity of the major mitochondrial processing peptidase (MPP). We report a global analysis of the N-proteome of yeast mitochondria, revealing the N-termini of 615 different proteins. Significantly more proteins than predicted contained cleavable presequences. We identified the intermediate cleaving peptidase Icp55, which removes an amino acid from a characteristic set of MPP-generated N-termini, solving the controversial situation of MPP specificity and suggesting that Icp55 converts instable intermediates into stable proteins. Our results suggest that Icp55 is critical for stabilization of the mitochondrial proteome and illustrate how the N-proteome can serve as rich source for a systematic analysis of mitochondrial protein targeting, cleavage and turnover.
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Affiliation(s)
- F-Nora Vögtle
- Institut für Biochemie und Molekularbiologie, ZBMZ, Universität Freiburg, 79104 Freiburg, Germany
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Ragheb D, Bompiani K, Dalal S, Klemba M. Evidence for catalytic roles for Plasmodium falciparum aminopeptidase P in the food vacuole and cytosol. J Biol Chem 2009; 284:24806-15. [PMID: 19574214 DOI: 10.1074/jbc.m109.018424] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The metalloenzyme aminopeptidase P catalyzes the hydrolysis of amino acids from the amino termini of peptides with a prolyl residue in the second position. The human malaria parasite Plasmodium falciparum expresses a homolog of aminopeptidase P during its asexual intraerythrocytic cycle. P. falciparum aminopeptidase P (PfAPP) shares with mammalian cytosolic aminopeptidase P a three-domain, homodimeric organization and is most active with Mn(II) as the cofactor. A distinguishing feature of PfAPP is a 120-amino acid amino-terminal extension that appears to be removed from the mature protein. PfAPP is present in the food vacuole and cytosol of the parasite, a distribution that suggests roles in vacuolar hemoglobin catabolism and cytosolic peptide turnover. To evaluate the plausibility of these putative functions, the stability and kinetic properties of recombinant PfAPP were evaluated at the acidic pH of the food vacuole and at the near-neutral pH of the cytosol. PfAPP exhibited high stability at 37 degrees C in the pH range 5.0-7.5. In contrast, recombinant human cytosolic APP1 was unstable and formed a high molecular weight aggregate at acidic pH. At both acidic and slightly basic pH values, PfAPP efficiently hydrolyzed the amino-terminal X-Pro bond of the nonapeptide bradykinin and of two globin pentapeptides that are potential in vivo substrates. These results provide support for roles for PfAPP in peptide catabolism in both the food vacuole and the cytosol and suggest that PfAPP has evolved a dual distribution in response to the metabolic needs of the intraerythrocytic parasite.
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Affiliation(s)
- Daniel Ragheb
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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Hsu YT, Su CY, Du HC, Jao SC, Li WS. Evaluation of Organophosphorus Chemicals-Degrading Enzymes: A Comparison ofEscherichia coliand Human Cytosolic Aminopeptidase P. Chem Biodivers 2008; 5:1401-11. [PMID: 18649306 DOI: 10.1002/cbdv.200890128] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yu-Ting Hsu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
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Li X, Lou Z, Li X, Zhou W, Ma M, Cao Y, Geng Y, Bartlam M, Zhang XC, Rao Z. Structure of human cytosolic X-prolyl aminopeptidase: a double Mn(II)-dependent dimeric enzyme with a novel three-domain subunit. J Biol Chem 2008; 283:22858-66. [PMID: 18515364 DOI: 10.1074/jbc.m710274200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
X-prolyl aminopeptidases catalyze the removal of a penultimate prolyl residue from the N termini of peptides. Mammalian X-prolyl aminopeptidases are shown to be responsible for the degradation of bradykinin, a blood pressure regulator peptide, and have been linked to myocardial infarction. The x-ray crystal structure of human cytosolic X-prolyl aminopeptidase (XPN-PEP1) was solved at a resolution of 1.6 angstroms. The structure reveals a dimer with a unique three-domain organization in each subunit, rather than the two domains common to all other known structures of X-prolyl aminopeptidase and prolidases. The C-terminal catalytic domain of XPNPEP1 coordinates two metal ions and shares a similar fold with other prolyl aminopeptidases. Metal content analysis and activity assays confirm that the enzyme is double Mn(II) dependent for its activity, which contrasts with the previous notion that each XPNPEP1 subunit contains only one Mn(II) ion. Activity assays on an E41A mutant demonstrate that the acidic residue, which was considered as a stabilizing factor in the protonation of catalytic residue His498, plays only a marginal role in catalysis. Further mutagenesis reveals the significance of the N-terminal domain and dimerization for the activity of XPNPEP1, and we provide putative structural explanations for their functional roles. Structural comparisons further suggest mechanisms for substrate selectivity in different X-prolyl peptidases.
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Affiliation(s)
- Xin Li
- College of Life Sciences & Tianjin State Laboratory of Protein Sciences, Nankai University, Tianjin 300071, China
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13
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Remote ischemic preconditioning: a novel protective method from ischemia reperfusion injury--a review. J Surg Res 2008; 150:304-30. [PMID: 19040966 DOI: 10.1016/j.jss.2007.12.747] [Citation(s) in RCA: 264] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 10/25/2007] [Accepted: 12/06/2007] [Indexed: 12/15/2022]
Abstract
BACKGROUND Restoration of blood supply to an organ after a critical period of ischemia results in parenchymal injury and dysfunction of the organ referred to as reperfusion injury. Ischemia reperfusion injury is often seen in organ transplants, major organ resections and in shock. Ischemic preconditioning (IPC) is an adaptational response of briefly ischemic tissues which serves to protect against subsequent prolonged ischemic insults and reperfusion injury. Ischemic preconditioning can be mechanical or pharmacological. Direct mechanical preconditioning in which the target organ is exposed to brief ischemia prior to prolonged ischemia has the benefit of reducing ischemia-reperfusion injury (IRI) but its main disadvantage is trauma to major vessels and stress to the target organ. Remote (inter organ) preconditioning is a recent observation in which brief ischemia of one organ has been shown to confer protection on distant organs without direct stress to the organ. AIM To discuss the evidence for remote IPC (RIPC), underlying mechanisms and possible clinical applications of RIPC. METHODS OF SEARCH: A Pubmed search with the keywords "ischemic preconditioning," "remote preconditioning," "remote ischemic preconditioning," and "ischemia reperfusion" was done. All articles on remote preconditioning up to September 2006 have been reviewed. Relevant reference articles from within these have been selected for further discussion. RESULTS Experimental studies have demonstrated that the heart, liver, lung, intestine, brain, kidney and limbs are capable of producing remote preconditioning when subjected to brief IR. Remote intra-organ preconditioning was first described in the heart where brief ischemia in one territory led to protection in other areas. Translation of RIPC to clinical application has been demonstrated by the use of brief forearm ischemia in preconditioning the heart prior to coronary bypass and in reducing endothelial dysfunction of the contra lateral limb. Recently protection of the heart has been demonstrated by remote hind limb preconditioning in children who underwent surgery on cardiopulmonary bypass for congenital heart disease. The RIPC stimulus presumably induces release of biochemical messengers which act either by the bloodstream or by the neurogenic pathway resulting in reduced oxidative stress and preservation of mitochondrial function. Studies have demonstrated endothelial NO, Free radicals, Kinases, Opioids, Catecholamines and K(ATP) channels as the candidate mechanism in remote preconditioning. Experiments have shown suppression of proinflammatory genes, expression of antioxidant genes and modulation of gene expression by RIPC as a novel method of IRI injury prevention. CONCLUSION There is strong evidence to support RIPC. The underlying mechanisms and pathways need further clarification. The effective use of RIPC needs to be investigated in clinical settings.
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14
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Abstract
The myocardium represents a major source of several families of peptide hormones under normal physiological conditions and the plasma concentrations of many of these "cardiac peptides" (or related pro-peptide fragments) are substantially augmented in many cardiac disease states. In addition to well-characterised endocrine functions of several of the cardiac peptides, pleiotropic functions within the myocardium and the coronary vasculature represent a significant aspect of their actions in health and disease. Here, we focus specifically on the cardioprotective roles of four major peptide families in myocardial ischemia and reperfusion: adrenomedullin, kinins, natriuretic peptides and the urocortins. The patterns of early release of all these peptides are consistent with roles as autacoid cardioprotective mediators. Clinical and experimental research indicates the early release and upregulation of many of these peptides by acute ischemia and there is a convincing body of evidence showing that exogenously administered adrenomedullin, bradykinin, ANP, BNP, CNP and urocortins are all markedly protective against experimental myocardial ischemia-reperfusion injury through a conserved series of cytoprotective signal transduction pathways. Intriguingly, all the peptides examined so far have the potential to salvage against infarction when administered specifically during early reperfusion. Thus, the myocardial secretion of peptide hormones likely represents an early protective response to ischemia. Further work is required to explore the potential therapeutic manipulation of these peptides in acute coronary syndromes and their promise as biomarkers of acute myocardial ischemia.
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Affiliation(s)
- Dwaine S Burley
- Department of Basic Sciences, The Royal Veterinary College, University of London, Royal College Street, London, UK
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15
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Richardt D, Dendorfer A, Tölg R, Dominiak P, Richardt G. Inhibition of nonexocytotic norepinephrine release by desipramine reduces myocardial infarction size. Can J Physiol Pharmacol 2006; 84:1185-9. [PMID: 17218983 DOI: 10.1139/y06-066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During myocardial ischemia, a substantial accumulation of norepinephrine occurs in the ischemic zone due to a local nonexocytotic release of norepinephrine. Norepinephrine release is driven by the neuronal monoamine transporter (NET), which reverses its usual transmembrane transport direction. We investigated whether this local accumulation of norepinephrine contributes to irreversible myocardial injury in an in vivo model of myocardial infarction. Male, anaesthetized Wistar rats were subjected to 30 min coronary occlusion and subsequent 120 min reperfusion. Five minutes prior to coronary occlusion, the NET inhibitor desipramine was administered intravenously. Infarct size (IS) was determined by TTC-staining and was related to the area at risk (AAR). The influence of desipramine on cardiac norepinephrine release was investigated in isolated perfused hearts with 30 min of regional ischemia. Norepinephrine was measured in the effluent from the hearts by HPLC and electrochemical detection. Desipramine (0.1–0.8 mg/kg) dose-dependently reduced infarct size (IS/AAR) from 0.54 to 0.21 and suppressed postischemic norepinephrine release from 245 to 108 pg/mL. In summary, the data indicate that nonexocytotic release of norepinephrine in myocardial ischemia exaggerates acute ischemic damage, because suppression of ischemia-induced release of norepinephrine by the tricyclic antidepressant desipramine effectively reduces infarct size in an in vivo model of myocardial ischemia.
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Affiliation(s)
- Doreen Richardt
- Institut für experimentelle und klinische Pharmakologie und Toxikologie, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Germany
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16
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Graham SC, Lilley PE, Lee M, Schaeffer PM, Kralicek AV, Dixon NE, Guss JM. Kinetic and crystallographic analysis of mutant Escherichia coli aminopeptidase P: insights into substrate recognition and the mechanism of catalysis. Biochemistry 2006; 45:964-75. [PMID: 16411772 DOI: 10.1021/bi0518904] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aminopeptidase P (APPro) is a manganese-dependent enzyme that cleaves the N-terminal amino acid from polypeptides where the second residue is proline. APPro shares a similar fold, substrate specificity, and catalytic mechanism with methionine aminopeptidase and prolidase. To investigate the roles of conserved residues at the active site, seven mutant forms of APPro were characterized kinetically and structurally. Mutation of individual metal ligands selectively abolished binding of either or both Mn(II) atoms at the active site, and none of these metal-ligand mutants had detectable catalytic activity. Mutation of the conserved active site residues His243 and His361 revealed that both are required for catalysis. We propose that His243 stabilizes substrate binding through an interaction with the carbonyl oxygen of the requisite proline residue of a substrate and that His361 stabilizes substrate binding and the gem-diol catalytic intermediate. Sequence, structural, and kinetic analyses reveal that His350, conserved in APPro and prolidase but not in methionine aminopeptidase, forms part of a hydrophobic binding pocket that gives APPro its proline specificity. Further, peptides in which the required proline residue is replaced by N-methylalanine or alanine are cleaved by APPro, but they are extremely poor substrates due to a loss of interactions between the prolidyl ring of the substrate and the hydrophobic proline-binding pocket.
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Affiliation(s)
- Stephen C Graham
- School of Molecular and Microbial Biosciences, University of Sydney, NSW 2006, Australia
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17
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Erşahin C, Szpaderska AM, Orawski AT, Simmons WH. Aminopeptidase P isozyme expression in human tissues and peripheral blood mononuclear cell fractions. Arch Biochem Biophys 2005; 435:303-10. [PMID: 15708373 DOI: 10.1016/j.abb.2004.12.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2004] [Revised: 12/21/2004] [Indexed: 11/30/2022]
Abstract
Aminopeptidase P (APP) isoforms specifically remove the N-terminal amino acid from peptides that have a proline residue in the second position. The mRNA levels of three different isoforms, each coded by a different gene, were determined in 16 human tissues and in peripheral blood mononuclear cell (PBMC) fractions by RT-PCR. The cytosolic isoform, APP1, and the cell surface membrane-bound isoform, APP2, are expressed in all of the human tissues and PBMC fractions examined. The very high expression of APP2 mRNA in kidney compared to other tissues was confirmed by enzyme activity measurements. Among the PBMC fractions, APP2 expression is highest in resting CD8(+) T cells, but decreases in these cells following their activation with phytohemagglutinin; in contrast, expression of APP2 increases in CD4(+) T cells upon activation. The third isoform, APP3, is a hypothetical protein identified by nucleotide sequencing. A detailed analysis of its amino acid sequence confirmed that the protein is an aminopeptidase P-like enzyme with greater similarity to Escherichia coli APP than to either APP1 or APP2. Two splice variants of APP3 exist, one of which is predicted to have a mitochondrial localization (APP3m) while the other is cytosolic (APP3c). Both forms are variably expressed in all of the human tissues and PBMC fractions examined.
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Affiliation(s)
- Cağatay Erşahin
- Department of Pathology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153, USA
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18
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Wolfrum S, Dendorfer A, Schutt M, Weidtmann B, Heep A, Tempel K, Klein HH, Dominiak P, Richardt G. Simvastatin acutely reduces myocardial reperfusion injury in vivo by activating the phosphatidylinositide 3-kinase/Akt pathway. J Cardiovasc Pharmacol 2005; 44:348-55. [PMID: 15475833 DOI: 10.1097/01.fjc.0000137162.14735.30] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Long-term pretreatment with statins reduces myocardial injury after acute ischemia and reperfusion by increasing the expression of endothelial nitric oxide synthase (eNOS). We hypothesized that statins may act rapidly enough to protect the myocardium from ischemia/reperfusion injury when given right at the beginning of the reperfusion period and tried to delineate the role of PI 3-kinase/Akt pathway in early eNOS activation. Activated simvastatin was given intravenously 3 minutes before starting the reperfusion after temporary coronary artery occlusion (CAO) in anaesthetized rats. Simvastatin significantly increased myocardial PI 3-kinase activity, AktSer473, and eNOSSer1177 phosphorylation and reduced infarct size by 42%. Infarct size reduction as well as activation of PI 3-kinase/Akt/eNOS pathway were not observed in rats co-treated with the PI 3-kinase inhibitor wortmannin. Contribution of eNOS was further delineated using the NOS inhibitor L-NAME, which could completely block cardioprotection by the statin. In summary, simvastatin acutely reduces the extent of myocardial necrosis in normocholesterolemic rats in an NO- dependent manner by activating the PI 3-kinase/Akt pathway. This is the first study demonstrating short-term cardioprotective effects of simvastatin in an in vivo model of ischemia/reperfusion.
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Affiliation(s)
- Sebastian Wolfrum
- Medical Clinic II, University of Schleswig-Holstein, Campus Lübeck, Germany.
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19
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Dendorfer A, Heidbreder M, Hellwig-Bürgel T, Jöhren O, Qadri F, Dominiak P. Deferoxamine induces prolonged cardiac preconditioning via accumulation of oxygen radicals. Free Radic Biol Med 2005; 38:117-24. [PMID: 15589380 DOI: 10.1016/j.freeradbiomed.2004.10.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Revised: 08/24/2004] [Accepted: 10/07/2004] [Indexed: 12/22/2022]
Abstract
Iron chelation by deferoxamine (DFO) blocks the Fenton reaction, but also inhibits prolyl hydroxylases and thereby activates certain hypoxia-inducible transcription factors (HIFs) that trigger cellular adaptation to hypoxia. Because both mechanisms may alleviate tissue damage in ischemia and reperfusion, we tried to differentiate their contribution to DFO-induced cardioprotection. Myocardial ischemia and reperfusion were induced in anesthetized Wistar rats. Infarct size was related to the ischemic area. Myocardial mRNA expression was determined by real-time PCR. Radical reactivity was probed in myocardial tissue slices with the redox-sensitive dye CM-H(2)DCFDA. Single ip applications of DFO (200 mg/kg) administered 2 h to 3 days before infarction reduced infarct size from 55 +/- 7% to 22-26%. Protection was abolished by the radical scavenger N-(2-mercaptopropionyl)glycine and the protein kinase C inhibitor chelerythrine when either was given 30 min before DFO, whereas subsequent application was ineffective. DFO did not alter the expression of various HIF target genes, whereas mRNAs of HIF-independent genes, aldose reductase and glucose transporter-4, were increased in infarcted myocardium 2 days after DFO treatment. Enhancement of superoxide activity by DFO could be demonstrated in vitro. Acute and prolonged myocardial preconditioning is triggered by DFO in response to accumulation of oxygen radicals and activation of protein kinase C.
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Affiliation(s)
- Andreas Dendorfer
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Luebeck, Ratzeburger Allee 160, D-23538 Luebeck, Germany.
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20
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Wolfrum S, Dendorfer A, Rikitake Y, Stalker TJ, Gong Y, Scalia R, Dominiak P, Liao JK. Inhibition of Rho-kinase leads to rapid activation of phosphatidylinositol 3-kinase/protein kinase Akt and cardiovascular protection. Arterioscler Thromb Vasc Biol 2004; 24:1842-7. [PMID: 15319269 PMCID: PMC2649731 DOI: 10.1161/01.atv.0000142813.33538.82] [Citation(s) in RCA: 269] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Rho-kinase activity is increased in cardiovascular diseases and in patients with cardiovascular risk factors. However, it is not known whether inhibition of Rho-kinase could lead to cardiovascular protection and, if so, by what mechanism. METHODS AND RESULTS In human endothelial cells, the Rho-kinase inhibitor, hydroxyfasudil (HF) (1 to 100 micromol/L), increased Akt serine-473 phosphorylation within 15 minutes, leading to a 2.2-fold and 4.0-fold increase in Akt kinase activity and nitric oxide (NO) release, respectively. Activation of Akt and eNOS by HF was completely blocked by the phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, LY294002 (10 micromol/L). To determine the physiological relevance of this pathway, we used 2 models of ischemia-reperfusion (I/R) injury. Acute administration of fasudil (10 mg/kg, intraperitoneal, 1 hour before ischemia) decreased leukocyte recruitment and adhesion to the mesenteric endothelium after I/R injury in wild-type but not eNOS-/- mice. Similarly, treatment with fasudil decreased myocardial infarct size by 38% in rats subjected to transient coronary artery occlusion. Cotreatment with 2 PI3-kinase inhibitors, wortmannin and LY294002, or the eNOS inhibitor, L-NAME, blocked the cardiovascular protective effects of fasudil. CONCLUSIONS Inhibition of Rho-kinase leads to the activation of the PI3-kinase/Akt/eNOS pathway and cardiovascular protection. These findings suggest that Rho-kinase may play an important role in mediating the inflammatory response to I/R injury.
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Affiliation(s)
- Sebastian Wolfrum
- Vascular Medicine Research Unit, Brigham & Women's Hospital and Harvard Medical School, Cambridge, Mass 02139, USA
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21
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Erşahin C, Szpaderska AM, Simmons WH. Rat and mouse membrane aminopeptidase P: structure analysis and tissue distribution. Arch Biochem Biophys 2003; 417:131-40. [PMID: 12941294 DOI: 10.1016/s0003-9861(03)00348-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Membrane-bound aminopeptidase P (mAPP) is a highly specific exopeptidase that removes the N-terminal amino acid only from a peptide (three amino acids or longer) that has a prolyl residue in the second position. mAPP can inactivate bradykinin, a potent vasodilating and cardioprotective peptide hormone, by hydrolyzing the Arg(1)-Pro(2) bond. Studies on the rat have shown that the metabolism of bradykinin is an important physiological role of this enzyme. We report here the complete coding sequences for rat and mouse mAPP determined from mRNA isolated from lung tissue. Key structural features that determine post-translational processing and substrate recognition and catalysis were identified based on sequence homologies and the crystal structure of Escherichia coli aminopeptidase P complexed with Pro-Leu. The tissue-specific expression of mAPP was studied using the polymerase chain reaction. The mAPP gene is widely, but variably, expressed in adult tissues of the rat and mouse and in mouse embryos.
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Affiliation(s)
- Cağatay Erşahin
- Department of Pathology, Loyola University Chicago Stritch School of Medicine, 2160 S. First Ave., Maywood, IL 60153, USA
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Koch M, Wendorf M, Dendorfer A, Wolfrum S, Schulze K, Spillmann F, Schultheiss HP, Tschöpe C. Cardiac kinin level in experimental diabetes mellitus: role of kininases. Am J Physiol Heart Circ Physiol 2003; 285:H418-23. [PMID: 12637359 DOI: 10.1152/ajpheart.00677.2002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diabetes mellitus impairs the cardiac kallikrein-kinin system by reducing cardiac kallikrein (KLK) and kininogen levels, a mechanism that may contribute to the deleterious outcome of cardiac ischemia in this disease. We studied left ventricular (LV) function and bradykinin (BK) coronary outflow in buffer-perfused, isolated working hearts (n = 7) of controls and streptozotocin (STZ)-induced diabetic rats before and after global ischemia. With the use of selective kininase inhibitors, the activities of angiotensin I-converting enzyme, aminopeptidase P, and neutral endopeptidase were determined by analyzing the degradation kinetics of exogenously administered BK during sequential coronary passages. Basal LV function and coronary flow were impaired in STZ-induced diabetic rats. Neither basal nor postischemic coronary BK outflow differed between control and diabetic hearts. Reperfusion after 15 min of ischemia induced a peak in coronary BK outflow that was of the same extent and duration in both groups. In diabetic hearts, total cardiac kininase activity was reduced by 41.4% with an unchanged relative kininase contribution compared with controls. In conclusion, despite reduced cardiac KLK synthesis, STZ-induced diabetic hearts are able to maintain kinin liberation under basal and ischemic conditions because of a primary impairment or a secondary downregulation of kinin-degrading enzymes.
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Affiliation(s)
- Matthias Koch
- Department of Cardiology and Pneumology, University Hospital Benjamin Franklin, Free University of Berlin, Berlin, Germany
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23
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Wolfrum S, Grimm M, Heidbreder M, Dendorfer A, Katus HA, Liao JK, Richardt G. Acute reduction of myocardial infarct size by a hydroxymethyl glutaryl coenzyme A reductase inhibitor is mediated by endothelial nitric oxide synthase. J Cardiovasc Pharmacol 2003; 41:474-80. [PMID: 12605027 DOI: 10.1097/00005344-200303000-00017] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In addition to their lipid-lowering properties, statins improve endothelial function by increasing the activity of endothelial nitric oxide synthase (eNOS). It was hypothesized that, by this mechanism, statins protect the myocardium from ischemia/reperfusion injury in normocholesterolemic animals. Rats were pretreated for 1 week with either cerivastatin (0.3 mg/kg/d) or placebo. Anesthetized animals underwent 30 minutes of coronary artery occlusion (CAO) followed by 180 minutes of reperfusion. In a separate set of experiments, the NOS inhibitor l-NAME (15 mg/kg; N -nitro-l-arginine methyl ester) was administered 15 minutes before CAO. Cerivastatin decreased infarct size by 49% (P < 0.05) without reducing plasma cholesterol levels. Cerivastatin increased myocardial eNOS mRNA and NOS activity and by 52% and 58% (P < 0.05), respectively. Cardioprotection and upregulation of eNOS activity evoked by cerivastatin were not observed in rats cotreated with l-NAME. These results show that statins reduce the extent of myocardial necrosis in normocholesterolemic rats after acute ischemia/reperfusion injury by increasing myocardial eNOS activity. Therefore, statins may protect the heart not only by reducing the incidence of ischemic events, but also by limiting cell damage during acute myocardial infarction.
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Baxter GF, Ebrahim Z. Role of bradykinin in preconditioning and protection of the ischaemic myocardium. Br J Pharmacol 2002; 135:843-54. [PMID: 11861312 PMCID: PMC1573212 DOI: 10.1038/sj.bjp.0704548] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- G F Baxter
- The Hatter Institute, University College London, London.
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