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Telianidis J, Hunter A, Widdop R, Kemp-Harper B, Pham V, McCarthy C, Chai SY. Inhibition of insulin-regulated aminopeptidase confers neuroprotection in a conscious model of ischemic stroke. Sci Rep 2023; 13:19722. [PMID: 37957163 PMCID: PMC10643421 DOI: 10.1038/s41598-023-46072-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Stroke is a leading cause of mortality and morbidity with a paucity of effective pharmacological treatments. We have previously identified insulin-regulated aminopeptidase (IRAP) as a potential target for the development of a new class of drugs for the treatment of stroke, as global deletion of this gene in mice significantly protected against ischemic damage. In the current study, we demonstrate that small molecular weight IRAP inhibitors reduce infarct volume and improve neurological outcome in a hypertensive animal model of ischemic stroke. The effects of two structurally distinct IRAP inhibitors (HFI419 or SJM164) were investigated in a model of stroke where the middle cerebral artery was transiently occluded with endothelin-1 in the conscious spontaneously hypertensive rat. IRAP inhibitor was administered into the lateral ventricle at 2 or 6 h after stroke, with subsequent doses delivered at 24, 48 and 70 h post-stroke. Functional outcomes were assessed prior to drug treatment, and on day 1 and 3 post-stroke. Histological analyses and neuroinflammatory cytokine profiling were conducted at 72 and 24 h post-stroke respectively. IRAP inhibitor treatment following stroke significantly reduced infarct volume and improved neurological and motor deficits. These protective effects were maintained even when the therapeutic window was extended to 6 h. Examination of the cellular architecture at 72 h post-stroke demonstrated that IRAP expression was upregulated in CD11b positive cells and activated astrocytes. Furthermore, IRAP inhibitor treatment significantly increased gene expression for interleukin 6 and C-C motif chemokine ligand 2 in the ischemic core. This study provides proof-of-principle that selective inhibition of IRAP activity with two structurally distinct IRAP inhibitors reduces infarct volume and improves functional outcome even when the first dose is administered 6 h post-stroke. This is the first direct evidence that IRAP inhibitors are a class of drug with potential use in the treatment of ischemic stroke.
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Affiliation(s)
- Jonathon Telianidis
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Andrew Hunter
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Robert Widdop
- Department Pharmacology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Barbara Kemp-Harper
- Department Pharmacology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Vi Pham
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Claudia McCarthy
- Department Pharmacology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Siew Yeen Chai
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia.
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2
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Hydrogen Peroxide Induced Toxicity Is Reversed by the Macrocyclic IRAP-Inhibitor HA08 in Primary Hippocampal Cell Cultures. Curr Issues Mol Biol 2022; 44:5000-5012. [PMID: 36286055 PMCID: PMC9601255 DOI: 10.3390/cimb44100340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/14/2022] [Accepted: 10/16/2022] [Indexed: 11/16/2022] Open
Abstract
Angiotensin IV (Ang IV), a metabolite of Angiotensin II, is a bioactive hexapeptide that inhibits the insulin-regulated aminopeptidase (IRAP). This transmembrane zinc metallopeptidase with many biological functions has in recent years emerged as a new pharmacological target. IRAP is expressed in a variety of tissues and can be found in high density in the hippocampus and neocortex, brain regions associated with cognition. Ang IV is known to improve memory tasks in experimental animals. One of the most potent IRAP inhibitors known today is the macrocyclic compound HA08 that is significantly more stable than the endogenous Ang IV. HA08 combines structural elements from Ang IV and the physiological substrates oxytocin and vasopressin, and binds to the catalytic site of IRAP. In the present study we evaluate whether HA08 can restore cell viability in rat primary cells submitted to hydrogen peroxide damage. After damaging the cells with hydrogen peroxide and subsequently treating them with HA08, the conceivable restoring effects of the IRAP inhibitor were assessed. The cellular viability was determined by measuring mitochondrial activity and lactate dehydrogenase (LDH) release. The mitochondrial activity was significantly higher in primary hippocampal cells, whereas the amount of LDH was unaffected. We conclude that the cell viability can be restored in this cell type by blocking IRAP with the potent macrocyclic inhibitor HA08, although the mechanism by which HA08 exerts its effects remains unclear.
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3
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Mendonça MM, da Cruz KR, Pinheiro DDS, Moraes GCA, Ferreira PM, Ferreira-Neto ML, da Silva ES, Gonçalves RV, Pedrino GR, Fajemiroye JO, Xavier CH. Dysregulation in erythrocyte dynamics caused by SARS-CoV-2 infection: possible role in shuffling the homeostatic puzzle during COVID-19. Hematol Transfus Cell Ther 2022; 44:235-245. [PMID: 35098037 PMCID: PMC8786672 DOI: 10.1016/j.htct.2022.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 01/04/2022] [Indexed: 12/15/2022] Open
Abstract
Introduction The evolving COVID-19 pandemic became a hallmark in human history, not only by changing lifestyles, but also by enriching scientific knowledge on viral infection and its consequences. Objective Although the management of cardiorespiratory changes is pivotal to a favorable prognosis during severe clinical findings, dysregulation of other systems caused by SARS-CoV-2 infection may imbalance erythrocyte dynamics, such as a bidirectional positive feedback loop pathophysiology. Method and Results Recent evidence shows that SARS-CoV-2 is capable of affecting the genetics and dynamics of erythrocytes and this coexists with a non-homeostatic function of cardiovascular, respiratory and renal systems during COVID-19. In hypothesis, SARS-CoV-2-induced systematical alterations of erythrocytes dynamics would constitute a setpoint for COVID-19-related multiple organ failure syndrome and death. Conclusion The present review covers the most frequent erythrocyte-related non-homeostatic findings during COVID-19 capable of providing mechanistic clues of SARS-CoV-2-induced infection and inspiring therapeutic-oriented scientific evidence.
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Affiliation(s)
| | - Kellen Rosa da Cruz
- Instituto de Ciências Biológicas da Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | | | | | - Patricia Maria Ferreira
- Instituto de Ciências Biológicas da Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | - Marcos Luiz Ferreira-Neto
- Instituto de Ciências Biomédicas da Universidade Federal de Uberlândia (ICBIM UFU), Uberlândia, MG, Brazil
| | | | | | | | - James O Fajemiroye
- Instituto de Ciências Biológicas da Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil
| | - Carlos Henrique Xavier
- Instituto de Ciências Biológicas da Universidade Federal de Goiás (UFG), Goiânia, GO, Brazil.
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Hemorphins-From Discovery to Functions and Pharmacology. Molecules 2021; 26:molecules26133879. [PMID: 34201982 PMCID: PMC8270332 DOI: 10.3390/molecules26133879] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 01/31/2023] Open
Abstract
During the last three decades, a variety of different studies on bioactive peptides that are opioid receptor ligands, have been carried out, with regard to their isolation and identification, as well as their molecular functions in living organisms. Thus, in this review, we would like to summarize the present state-of-the art concerning hemorphins, methodological aspects of their identification, and their potential role as therapeutic agents. We have collected and discussed articles describing hemorphins, from their discovery up until now, thus presenting a very wide spectrum of their characteristic and applications. One of the major assets of the present paper is a combination of analytical and pharmacological aspects of peptides described by a team who participated in the initial research on hemorphins. This review is, in part, focused on the analysis of endogenous opioid peptides in biological samples using advanced techniques, description of the identification of synthetic/endogenous hemorphins, their involvement in pharmacology, learning, pain and other function. Finally, the part regarding hemorphin analogues and their synthesis, has been added.
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5
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Insights into the Interaction of LVV-Hemorphin-7 with Angiotensin II Type 1 Receptor. Int J Mol Sci 2020; 22:ijms22010209. [PMID: 33379211 PMCID: PMC7795518 DOI: 10.3390/ijms22010209] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/17/2020] [Accepted: 12/24/2020] [Indexed: 12/17/2022] Open
Abstract
Hemorphins are known for their role in the control of blood pressure. Recently, we revealed the positive modulation of the angiotensin II (AngII) type 1 receptor (AT1R) by LVV-hemorphin-7 (LVV-H7) in human embryonic kidney (HEK293) cells. Here, we examined the molecular binding behavior of LVV-H7 on AT1R and its effect on AngII binding using a nanoluciferase-based bioluminescence resonance energy transfer (NanoBRET) assay in HEK293FT cells, as well as molecular docking and molecular dynamics (MD) studies. Saturation and real-time kinetics supported the positive effect of LVV-H7 on the binding of AngII. While the competitive antagonist olmesartan competed with AngII binding, LVV-H7 slightly, but significantly, decreased AngII’s kD by 2.6 fold with no effect on its Bmax. Molecular docking and MD simulations indicated that the binding of LVV-H7 in the intracellular region of AT1R allosterically potentiates AngII binding. LVV-H7 targets residues on intracellular loops 2 and 3 of AT1R, which are known binding sites of allosteric modulators in other GPCRs. Our data demonstrate the allosteric effect of LVV-H7 on AngII binding, which is consistent with the positive modulation of AT1R activity and signaling previously reported. This further supports the pharmacological targeting of AT1R by hemorphins, with implications in vascular and renal physiology.
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Vear A, Gaspari T, Thompson P, Chai SY. Is There an Interplay Between the Functional Domains of IRAP? Front Cell Dev Biol 2020; 8:585237. [PMID: 33134302 PMCID: PMC7550531 DOI: 10.3389/fcell.2020.585237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/08/2020] [Indexed: 01/16/2023] Open
Abstract
As a member of the M1 family of aminopeptidases, insulin regulated aminopeptidase (IRAP) is characterized by distinct binding motifs at the active site in the C-terminal domain that mediate the catalysis of peptide substrates. However, what makes IRAP unique in this family of enzymes is that it also possesses trafficking motifs at the N-terminal domain which regulate the movement of IRAP within different intracellular compartments. Research on the role of IRAP has focused predominantly on the C-terminus catalytic domain in different physiological and pathophysiological states ranging from pregnancy to memory loss. Many of these studies have utilized IRAP inhibitors, that bind competitively to the active site of IRAP, to explore the functional significance of its catalytic activity. However, it is unknown whether these inhibitors are able to access intracellular sites where IRAP is predominantly located in a basal state as the enzyme may need to be at the cell surface for the inhibitors to mediate their effects. This property of IRAP has often been overlooked. Interestingly, in some pathophysiological states, the distribution of IRAP is altered. This, together with the fact that IRAP possesses trafficking motifs, suggest the localization of IRAP may play an important role in defining its physiological or pathological functions and provide insights into the interplay between the two functional domains of the protein.
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Affiliation(s)
- Anika Vear
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Tracey Gaspari
- Department of Pharmacology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Philip Thompson
- Department of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Siew Yeen Chai
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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Ali A, Alzeyoudi SAR, Almutawa SA, Alnajjar AN, Al Dhaheri Y, Vijayan R. Camel Hemorphins Exhibit a More Potent Angiotensin-I Converting Enzyme Inhibitory Activity than Other Mammalian Hemorphins: An In Silico and In Vitro Study. Biomolecules 2020; 10:E486. [PMID: 32210030 PMCID: PMC7175181 DOI: 10.3390/biom10030486] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/17/2020] [Accepted: 03/20/2020] [Indexed: 02/06/2023] Open
Abstract
Angiotensin-I converting enzyme (ACE) is a zinc metallopeptidase that has an important role in regulating the renin-angiotensin-aldosterone system (RAAS). It is also an important drug target for the management of cardiovascular diseases. Hemorphins are endogenous peptides that are produced by proteolytic cleavage of beta hemoglobin. A number of studies have reported various therapeutic activities of hemorphins. Previous reports have shown antihypertensive action of hemorphins via the inhibition of ACE. The sequence of hemorphins is highly conserved among mammals, except in camels, which harbors a unique Q>R variation in the peptide. Here, we studied the ACE inhibitory activity of camel hemorphins (LVVYPWTRRF and YPWTRRF) and non-camel hemorphins (LVVYPWTQRF and YPWTQRF). Computational methods were used to determine the most likely binding pose and binding affinity of both camel and non-camel hemorphins within the active site of ACE. Molecular dynamics simulations showed that the peptides interacted with critical residues in the active site of ACE. Notably, camel hemorphins showed higher binding affinity and sustained interactions with all three subsites of the ACE active site. An in vitro ACE inhibition assay showed that the IC50 of camel hemorphins were significantly lower than the IC50 of non-camel hemorphins.
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Affiliation(s)
| | | | | | | | | | - Ranjit Vijayan
- Department of Biology, College of Science, United Arab Emirates University, PO Box 15551 Al Ain, Abu Dhabi, UAE
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Barlow N, Vanga SR, Sävmarker J, Sandström A, Burns P, Hallberg A, Åqvist J, Gutiérrez-de-Terán H, Hallberg M, Larhed M, Chai SY, Thompson PE. Macrocyclic peptidomimetics as inhibitors of insulin-regulated aminopeptidase (IRAP). RSC Med Chem 2020; 11:234-244. [PMID: 33479630 DOI: 10.1039/c9md00485h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 11/21/2019] [Indexed: 12/25/2022] Open
Abstract
Macrocyclic analogues of the linear hexapeptide, angiotensin IV (AngIV) have proved to be potent inhibitors of insulin-regulated aminopeptidase (IRAP, oxytocinase, EC 3.4.11.3). Along with higher affinity, macrocycles may also offer better metabolic stability, membrane permeability and selectivity, however predicting the outcome of particular cycle modifications is challenging. Here we describe the development of a series of macrocyclic IRAP inhibitors with either disulphide, olefin metathesis or lactam bridges and variations of ring size and other functionality. The binding mode of these compounds is proposed based on molecular dynamics analysis. Estimation of binding affinities (ΔG) and relative binding free energies (ΔΔG) with the linear interaction energy (LIE) method and free energy perturbation (FEP) method showed good general agreement with the observed inhibitory potency. Experimental and calculated data highlight the cumulative importance of an intact N-terminal peptide, the specific nature of the macrocycle, the phenolic oxygen and the C-terminal functionality.
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Affiliation(s)
- Nicholas Barlow
- Department of Medicinal Chemistry , BMC , Uppsala University , P.O. Box 574 , SE-751 23 Uppsala , Sweden.,Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Parkville , Victoria 3052 , Australia .
| | - Sudarsana Reddy Vanga
- Department of Cell and Molecular Biology , BMC , Uppsala University , Box 596 , SE-751 24 Uppsala , Sweden
| | - Jonas Sävmarker
- The Beijer Laboratory , Department of Medicinal Chemistry , BMC , Uppsala University , P.O. Box 574 , SE-751 23 Uppsala , Sweden
| | - Anja Sandström
- The Beijer Laboratory , Department of Medicinal Chemistry , BMC , Uppsala University , P.O. Box 574 , SE-751 23 Uppsala , Sweden
| | - Peta Burns
- Biomedicine Discovery Institute , Department of Physiology , Monash University , Clayton , Victoria 3800 , Australia
| | - Anders Hallberg
- Department of Medicinal Chemistry , BMC , Uppsala University , P.O. Box 574 , SE-751 23 Uppsala , Sweden
| | - Johan Åqvist
- Department of Cell and Molecular Biology , BMC , Uppsala University , Box 596 , SE-751 24 Uppsala , Sweden
| | - Hugo Gutiérrez-de-Terán
- Department of Cell and Molecular Biology , BMC , Uppsala University , Box 596 , SE-751 24 Uppsala , Sweden
| | - Mathias Hallberg
- The Beijer Laboratory , Department of Pharmaceutical Biosciences , Division of Biological Research on Drug Dependence , BMC , Uppsala University , P.O. Box 591 , SE-751 24 Uppsala , Sweden
| | - Mats Larhed
- Department of Medicinal Chemistry , BMC , Uppsala University , P.O. Box 574 , SE-751 23 Uppsala , Sweden.,Science for Life Laboratory , Department of Medicinal Chemistry , BMC , Uppsala University , SE-751 24 Uppsala , Sweden
| | - Siew Yeen Chai
- Biomedicine Discovery Institute , Department of Physiology , Monash University , Clayton , Victoria 3800 , Australia
| | - Philip E Thompson
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Parkville , Victoria 3052 , Australia .
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9
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Ali A, Palakkott A, Ashraf A, Al Zamel I, Baby B, Vijayan R, Ayoub MA. Positive Modulation of Angiotensin II Type 1 Receptor-Mediated Signaling by LVV-Hemorphin-7. Front Pharmacol 2019; 10:1258. [PMID: 31708782 PMCID: PMC6823245 DOI: 10.3389/fphar.2019.01258] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/30/2019] [Indexed: 12/13/2022] Open
Abstract
Hemorphins are hemoglobin β-chain–derived peptides initially known for their analgesic effects via binding to the opioid receptors belonging to the family of G protein–coupled receptor (GPCR), as well as their physiological action on blood pressure. However, their molecular mechanisms in the regulation of blood pressure are not fully understood. Studies have reported an antihypertensive action via the inhibition of the angiotensin-converting enzyme, a key enzyme in the renin–angiotensin system. In this study, we hypothesized that hemorphins may also target angiotensin II (AngII) type 1 receptor (AT1R) as a key GPCR in the renin–angiotensin system. To investigate this, we examined the effects of LVV–hemorphin-7 on AT1R transiently expressed in human embryonic kidney (HEK293) cells using bioluminescence resonance energy transfer (BRET) technology for the assessment of AT1R/Gαq coupling and β-arrestin 2 recruitment. Interestingly, while LVV–hemorphin-7 alone had no significant effect on BRET signals between AT1R and Gαq or β-arrestin 2, it nicely potentiated AngII-induced BRET signals and significantly increased AngII potency. The BRET data were also correlated with AT1R downstream signaling with LVV–hemorphin-7 potentiating the canonical AngII-mediated Gq-dependent inositol phosphate pathway as well as the activation of the extracellular signal–regulated kinases (ERK1/2). Both AngII and LVV–hemorphin-7–mediated responses were fully abolished by AT1R antagonist demonstrating the targeting of the active conformation of AT1R. Our data report for the first time the targeting and the positive modulation of AT1R signaling by hemorphins, which may explain their role in the physiology and pathophysiology of both vascular and renal systems. This finding further consolidates the pharmacological targeting of GPCRs by hemorphins as previously shown for the opioid receptors in analgesia opening a new era for investigating the role of hemorphins in physiology and pathophysiology via the targeting of GPCR pharmacology and signaling.
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Affiliation(s)
- Amanat Ali
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Abdulrasheed Palakkott
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Arshida Ashraf
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Isra Al Zamel
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bincy Baby
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ranjit Vijayan
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mohammed Akli Ayoub
- Department of Biology, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
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Molecular insights into the interaction of hemorphin and its targets. Sci Rep 2019; 9:14747. [PMID: 31611567 PMCID: PMC6791854 DOI: 10.1038/s41598-019-50619-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 09/17/2019] [Indexed: 12/20/2022] Open
Abstract
Hemorphins are atypical endogenous opioid peptides produced by the cleavage of hemoglobin beta chain. Several studies have reported the therapeutic potential of hemorphin in memory enhancement, blood regulation, and analgesia. However, the mode of interaction of hemorphin with its target remains largely elusive. The decapeptide LVV-hemorphin-7 is the most stable form of hemorphin. It binds with high affinity to mu-opioid receptors (MOR), angiotensin-converting enzyme (ACE) and insulin-regulated aminopeptidase (IRAP). In this study, computational methods were used extensively to elucidate the most likely binding pose of mammalian LVV-hemorphin-7 with the aforementioned proteins and to calculate the binding affinity. Additionally, alignment of mammalian hemorphin sequences showed that the hemorphin sequence of the camel harbors a variation - a Q > R substitution at position 8. This study also investigated the binding affinity and the interaction mechanism of camel LVV-hemorphin-7 with these proteins. To gain a better understanding of the dynamics of the molecular interactions between the selected targets and hemorphin peptides, 100 ns molecular dynamics simulations of the best-ranked poses were performed. Simulations highlighted major interactions between the peptides and key residues in the binding site of the proteins. Interestingly, camel hemorphin had a higher binding affinity and showed more interactions with all three proteins when compared to the canonical mammalian LVV-hemorphin-7. Thus, camel LVV-hemorphin-7 could be explored as a potent therapeutic agent for memory loss, hypertension, and analgesia.
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Ho JK, Nation DA. Cognitive benefits of angiotensin IV and angiotensin-(1-7): A systematic review of experimental studies. Neurosci Biobehav Rev 2018; 92:209-225. [PMID: 29733881 DOI: 10.1016/j.neubiorev.2018.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/23/2018] [Accepted: 05/02/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To explore effects of the brain renin-angiotensin system (RAS) on cognition. DESIGN Systematic review of experimental (non-human) studies assessing cognitive effects of RAS peptides angiotensin-(3-8) [Ang IV] and angiotensin-(1-7) [Ang-(1-7)] and their receptors, the Ang IV receptor (AT4R) and the Mas receptor. RESULTS Of 450 articles identified, 32 met inclusion criteria. Seven of 11 studies of normal animals found Ang IV had beneficial effects on tests of passive or conditioned avoidance and object recognition. In models of cognitive deficit, eight of nine studies found Ang IV and its analogs (Nle1-Ang IV, dihexa, LVV-hemorphin-7) improved performance on spatial working memory and passive avoidance tasks. Two of three studies examining Ang-(1-7) found it benefited memory. Mas receptor removal was associated with reduced fear memory in one study. CONCLUSION Studies of cognitive impairment show salutary effects of acute administration of Ang IV and its analogs, as well as AT4R activation. Brain RAS peptides appear most effective administered intracerebroventricularly, close to the time of learning acquisition or retention testing. Ang-(1-7) shows anti-dementia qualities.
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Affiliation(s)
- Jean K Ho
- Department of Psychology, University of Southern California, Los Angeles, CA, USA.
| | - Daniel A Nation
- Department of Psychology, University of Southern California, Los Angeles, CA, USA.
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Vanga SR, Sävmarker J, Ng L, Larhed M, Hallberg M, Åqvist J, Hallberg A, Chai SY, Gutiérrez-de-Terán H. Structural Basis of Inhibition of Human Insulin-Regulated Aminopeptidase (IRAP) by Aryl Sulfonamides. ACS OMEGA 2018; 3:4509-4521. [PMID: 30023895 PMCID: PMC6045421 DOI: 10.1021/acsomega.8b00595] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/16/2018] [Indexed: 05/07/2023]
Abstract
The insulin-regulated aminopeptidase (IRAP) is a membrane-bound zinc metallopeptidase with many important regulatory functions. It has been demonstrated that inhibition of IRAP by angiotensin IV (Ang IV) and other peptides, as well as more druglike inhibitors, improves cognition in several rodent models. We recently reported a series of aryl sulfonamides as small-molecule IRAP inhibitors and a promising scaffold for pharmacological intervention. We have now expanded with a number of derivatives, report their stability in liver microsomes, and characterize the activity of the whole series in a new assay performed on recombinant human IRAP. Several compounds, such as the new fluorinated derivative 29, present submicromolar affinity and high metabolic stability. Starting from the two binding modes previously proposed for the sulfonamide scaffold, we systematically performed molecular dynamics simulations and binding affinity estimation with the linear interaction energy method for the full compound series. The significant agreement with experimental affinities suggests one of the binding modes, which was further confirmed by the excellent correlation for binding affinity differences between the selected pair of compounds obtained by rigorous free energy perturbation calculations. The new experimental data and the computationally derived structure-activity relationship of the sulfonamide series provide valuable information for further lead optimization of novel IRAP inhibitors.
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Affiliation(s)
- Sudarsana Reddy Vanga
- Department
of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751
24 Uppsala, Sweden
| | - Jonas Sävmarker
- Department of Medicinal Chemistry and Science for Life Laboratory, Department
of Medicinal Chemistry, Uppsala University,
BMC, SE-751 24 Uppsala, Sweden
| | - Leelee Ng
- Biomedicine
Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Mats Larhed
- Department of Medicinal Chemistry and Science for Life Laboratory, Department
of Medicinal Chemistry, Uppsala University,
BMC, SE-751 24 Uppsala, Sweden
| | - Mathias Hallberg
- The
Beijer Laboratory, Department of Pharmaceutical Biosciences, Division
of Biological Research on Drug Dependence, Uppsala University, BMC, SE-751 23 Uppsala, Sweden
| | - Johan Åqvist
- Department
of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751
24 Uppsala, Sweden
| | - Anders Hallberg
- Department of Medicinal Chemistry and Science for Life Laboratory, Department
of Medicinal Chemistry, Uppsala University,
BMC, SE-751 24 Uppsala, Sweden
| | - Siew Yeen Chai
- Biomedicine
Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
- E-mail: . Phone: +61 3 990 52515. Fax: +61 3 990 52547 (S.Y.C.)
| | - Hugo Gutiérrez-de-Terán
- Department
of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751
24 Uppsala, Sweden
- E-mail: . Phone: +46 18 471 5056. Fax: +46 18 53 69 71 (H.G.-d.-T.)
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Domenger D, Cudennec B, Kouach M, Touche V, Landry C, Lesage J, Gosselet F, Lestavel S, Goossens JF, Dhulster P, Ravallec R. Food-Derived Hemorphins Cross Intestinal and Blood-Brain Barriers In Vitro. Front Endocrinol (Lausanne) 2018; 9:159. [PMID: 29692758 PMCID: PMC5903475 DOI: 10.3389/fendo.2018.00159] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 03/26/2018] [Indexed: 01/08/2023] Open
Abstract
A qualitative study is presented, where the main question was whether food-derived hemorphins, i.e., originating from digested alimentary hemoglobin, could pass the intestinal barrier and/or the blood-brain barrier (BBB). Once absorbed, hemorphins are opioid receptor (OR) ligands that may interact with peripheral and central OR and have effects on food intake and energy balance regulation. LLVV-YPWT (LLVV-H4), LVV-H4, VV-H4, VV-YPWTQRF (VV-H7), and VV-H7 hemorphins that were previously identified in the 120 min digest resulting from the simulated gastrointestinal digestion of hemoglobin have been synthesized to be tested in in vitro models of passage of IB and BBB. LC-MS/MS analyses yielded that all hemorphins, except the LLVV-H4 sequence, were able to cross intact the human intestinal epithelium model with Caco-2 cells within 5-60 min when applied at 5 mM. Moreover, all hemorphins crossed intact the human BBB model with brain-like endothelial cells (BLEC) within 30 min when applied at 100 µM. Fragments of these hemorphins were also detected, especially the YPWT common tetrapeptide that retains OR-binding capacity. A cAMP assay performed in Caco-2 cells indicates that tested hemorphins behave as OR agonists in these cells by reducing cAMP production. We further provide preliminary results regarding the effects of hemorphins on tight junction proteins, specifically here the claudin-4 that is involved in paracellular permeability. All hemorphins at 100 µM, except the LLVV-H4 peptide, significantly decreased claudin-4 mRNA levels in the Caco-2 intestinal model. This in vitro study is a first step toward demonstrating food-derived hemorphins bioavailability which is in line with the growing body of evidence supporting physiological functions for food-derived peptides.
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Affiliation(s)
- Dorothée Domenger
- Université de Lille INRA, ISA, Université d’Artois, Université Littoral Côte d’Opale, EA 7394-ICV Institut Charles Viollette, Lille, France
| | - Benoit Cudennec
- Université de Lille INRA, ISA, Université d’Artois, Université Littoral Côte d’Opale, EA 7394-ICV Institut Charles Viollette, Lille, France
- *Correspondence: Benoit Cudennec, ; Rozenn Ravallec,
| | - Mostafa Kouach
- Plateau de Spectrométrie de Masse “PSM-GRITA”, EA 7365, Faculté de Pharmacie, Université de Lille, Lille, France
| | - Véronique Touche
- Université de Lille INSERM, CHU Lille, Institut Pasteur de Lille, U1011 – EGID, Lille, France
| | - Christophe Landry
- Université d’Artois EA 2465, Laboratoire de la Barrière Hémato-Encéphalique (LBHE), Lens, France
| | - Jean Lesage
- Université Lille Nord de France, Unité Environnement Périnatal et Croissance EA 4489, Équipe dénutritions maternelles périnatales, Université Lille 1, Villeneuve-d’Ascq, France
| | - Fabien Gosselet
- Université d’Artois EA 2465, Laboratoire de la Barrière Hémato-Encéphalique (LBHE), Lens, France
| | - Sophie Lestavel
- Université de Lille INSERM, CHU Lille, Institut Pasteur de Lille, U1011 – EGID, Lille, France
| | - Jean-François Goossens
- Plateau de Spectrométrie de Masse “PSM-GRITA”, EA 7365, Faculté de Pharmacie, Université de Lille, Lille, France
| | - Pascal Dhulster
- Université de Lille INRA, ISA, Université d’Artois, Université Littoral Côte d’Opale, EA 7394-ICV Institut Charles Viollette, Lille, France
| | - Rozenn Ravallec
- Université de Lille INRA, ISA, Université d’Artois, Université Littoral Côte d’Opale, EA 7394-ICV Institut Charles Viollette, Lille, France
- *Correspondence: Benoit Cudennec, ; Rozenn Ravallec,
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Balmus IM, Ciobica A. Main Plant Extracts' Active Properties Effective on Scopolamine-Induced Memory Loss. Am J Alzheimers Dis Other Demen 2017; 32:418-428. [PMID: 28643520 PMCID: PMC10852862 DOI: 10.1177/1533317517715906] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease leads to progressive cognitive function loss, which may impair both intellectual capacities and psychosocial aspects. Although the current knowledge points to a multifactorial character of Alzheimer's disease, the most issued pathological hypothesis remains the cholinergic theory. The main animal model used in cholinergic theory research is the scopolamine-induced memory loss model. Although, in some cases, a temporary symptomatic relief can be obtained through targeting the cholinergic or glutamatergic neurotransmitter systems, no current treatment is able to stop or slow cognitive impairment. Many potentially successful therapies are often blocked by the blood-brain barrier since it exhibits permeability only for several classes of active molecules. However, the plant extracts' active molecules are extremely diverse and heterogeneous regarding the biochemical structure. In this way, many active compounds constituting the recently tested plant extracts may exhibit the same general effect on acetylcholine pathway, but on different molecular ground, which can be successfully used in Alzheimer's disease adjuvant therapy.
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Affiliation(s)
- Ioana-Miruna Balmus
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania
| | - Alin Ciobica
- Department of Research, Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania
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15
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Domenger D, Caron J, Belguesmia Y, Lesage J, Dhulster P, Ravallec R, Cudennec B. Bioactivities of hemorphins released from bovine haemoglobin gastrointestinal digestion: Dual effects on intestinal hormones and DPP-IV regulations. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.06.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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16
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Sen S, Gürel N, Ufuktepe B, Özünal ZG, Büyüklü Ç, Üresin Y. Evaluating the relationship of blood pressure, plasma angiotensin peptides and aldosterone with cognitive functions in patients with hypertension. EXCLI JOURNAL 2017; 16:245-255. [PMID: 28507470 PMCID: PMC5427471 DOI: 10.17179/excli2016-725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/10/2017] [Indexed: 01/15/2023]
Abstract
Renin Angiotensin Aldosterone System (RAAS) plays an important role in the development of hypertension. On the other hand, hypertension is a well-known and independent risk factor for cognitive impairment. The aim of the present study was to evaluate the relationship of blood pressure control, plasma angiotensin peptides and aldosterone with cognitive functions. Forty-one patients who were under treatment with the same antihypertensive medications for at least three months were included in the study. Plasma angiotensin II, angiotensin 1-7, angiotensin IV, and aldosterone concentrations were analyzed using an enzyme-linked immunosorbent assay (ELISA). Standardized Mini Mental State Examination (SMMSE) was used to evaluate cognitive functions. When the participants were grouped according to their SMMSE scores (cut-off value: 26 points), we determined significant differences between systolic blood pressure (SBP) levels, diastolic blood pressure levels, plasma angiotensin II and angiotensin 1-7 concentrations of the groups. When the participants were stratified according to their SBP levels (cut-off value: 140 mm Hg), we found significant differences in SMMSE scores and plasma angiotensin IV concentrations of the groups. A negative correlation between SBP and SMMSE scores and strong linear correlations among angiotensin peptides levels were determined. The relationship found between SBP and SMMSE in the present study was compatible with the literature. Our 33 patients were using at least one angiotensin II receptor blocker (ARB). Regarding AT1 receptor blockage, the significant association between higher SMMSE scores and increased angiotensin peptides may support a finding that ARBs prevent dementia and improve cognitive function. Further larger studies are needed to confirm and prove the relation of RAAS biochemical parameters with cognitive function.
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Affiliation(s)
- Selçuk Sen
- Department of Medical Pharmacology, Istanbul Faculty of Medicine, Istanbul University, 34390 Fatih, Istanbul, Turkey
| | - Nermin Gürel
- Department of Medical Pharmacology, Istanbul Faculty of Medicine, Istanbul University, 34390 Fatih, Istanbul, Turkey
| | - Baran Ufuktepe
- Department of Medical Pharmacology, Istanbul Faculty of Medicine, Istanbul University, 34390 Fatih, Istanbul, Turkey
| | - Zeynep Günes Özünal
- Department of Medical Pharmacology, Istanbul Faculty of Medicine, Istanbul University, 34390 Fatih, Istanbul, Turkey
| | - Çagla Büyüklü
- Department of Neuroscience, Institute of Experimental Medicine, Istanbul University, 34393 Fatih, Istanbul, Turkey
| | - Yagiz Üresin
- Department of Medical Pharmacology, Istanbul Faculty of Medicine, Istanbul University, 34390 Fatih, Istanbul, Turkey
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17
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Yeatman HR, Albiston AL, Burns P, Chai SY. Forebrain neurone-specific deletion of insulin-regulated aminopeptidase causes age related deficits in memory. Neurobiol Learn Mem 2016; 136:174-182. [PMID: 27713012 DOI: 10.1016/j.nlm.2016.09.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 09/19/2016] [Accepted: 09/25/2016] [Indexed: 12/27/2022]
Abstract
Central infusion of Insulin-Regulated Aminopeptidase (IRAP) inhibitors improves memory in both normal rodents and in models of memory deficit. However, in contrast, the global IRAP knockout mice (KO) demonstrate age-accelerated spatial memory deficits and no improvements in performance in any memory tasks. Potentially, the observed memory deficit could be due to the absence of IRAP in the developing brain. We therefore generated a postnatal forebrain neuron-specific IRAP knockout mouse line (CamKIIalphaCre; IRAPlox/lox). Unexpectedly, we demonstrated that postnatal deletion of IRAP in the brain results in significant deficits in both spatial reference and object recognition memory at three months of age, although spatial working memory remained intact. These results indicate a significant role for IRAP in postnatal brain development and normal function of the hippocampus in adulthood.
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Affiliation(s)
- Holly R Yeatman
- Florey Neuroscience Institutes and Centre for Neuroscience, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Anthony L Albiston
- College of Health and Biomedicine, VU St Albans, Victoria 3021, Australia
| | - Peta Burns
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Siew Yeen Chai
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia.
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18
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Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
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Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
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19
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Hermans SJ, Ascher DB, Hancock NC, Holien JK, Michell BJ, Chai SY, Morton CJ, Parker MW. Crystal structure of human insulin-regulated aminopeptidase with specificity for cyclic peptides. Protein Sci 2014; 24:190-9. [PMID: 25408552 DOI: 10.1002/pro.2604] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 11/10/2014] [Indexed: 11/12/2022]
Abstract
Insulin-regulated aminopeptidase (IRAP or oxytocinase) is a membrane-bound zinc-metallopeptidase that cleaves neuroactive peptides in the brain and produces memory enhancing effects when inhibited. We have determined the crystal structure of human IRAP revealing a closed, four domain arrangement with a large, mostly buried cavity abutting the active site. The structure reveals that the GAMEN exopeptidase loop adopts a very different conformation from other aminopeptidases, thus explaining IRAP's unique specificity for cyclic peptides such as oxytocin and vasopressin. Computational docking of a series of IRAP-specific cognitive enhancers into the crystal structure provides a molecular basis for their structure-activity relationships and demonstrates that the structure will be a powerful tool in the development of new classes of cognitive enhancers for treating a variety of memory disorders such as Alzheimer's disease.
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Affiliation(s)
- Stefan J Hermans
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, Melbourne, Victoria, 3065, Australia
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20
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Wright JW, Kawas LH, Harding JW. The development of small molecule angiotensin IV analogs to treat Alzheimer's and Parkinson's diseases. Prog Neurobiol 2014; 125:26-46. [PMID: 25455861 DOI: 10.1016/j.pneurobio.2014.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 02/07/2023]
Abstract
Alzheimer's (AD) and Parkinson's (PD) diseases are neurodegenerative diseases presently without effective drug treatments. AD is characterized by general cognitive impairment, difficulties with memory consolidation and retrieval, and with advanced stages episodes of agitation and anger. AD is increasing in frequency as life expectancy increases. Present FDA approved medications do little to slow disease progression and none address the underlying progressive loss of synaptic connections and neurons. New drug design approaches are needed beyond cholinesterase inhibitors and N-methyl-d-aspartate receptor antagonists. Patients with PD experience the symptomatic triad of bradykinesis, tremor-at-rest, and rigidity with the possibility of additional non-motor symptoms including sleep disturbances, depression, dementia, and autonomic nervous system failure. This review summarizes available information regarding the role of the brain renin-angiotensin system (RAS) in learning and memory and motor functions, with particular emphasis on research results suggesting a link between angiotensin IV (AngIV) interacting with the AT4 receptor subtype. Currently there is controversy over the identity of this AT4 receptor protein. Albiston and colleagues have offered convincing evidence that it is the insulin-regulated aminopeptidase (IRAP). Recently members of our laboratory have presented evidence that the brain AngIV/AT4 receptor system coincides with the brain hepatocyte growth factor/c-Met receptor system. In an effort to resolve this issue we have synthesized a number of small molecule AngIV-based compounds that are metabolically stable, penetrate the blood-brain barrier, and facilitate compromised memory and motor systems. These research efforts are described along with details concerning a recently synthesized molecule, Dihexa that shows promise in overcoming memory and motor dysfunctions by augmenting synaptic connectivity via the formation of new functional synapses.
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Affiliation(s)
- John W Wright
- Departments of Psychology, Integrative Physiology and Neuroscience and Program in Biotechnology, Washington State University, Pullman, WA 99164-4820, USA; M3 Biotechnology, Inc., 4000 Mason Rd Suite 300, Box 352141, Seattle, WA 98195-2141, USA.
| | - Leen H Kawas
- Departments of Psychology, Integrative Physiology and Neuroscience and Program in Biotechnology, Washington State University, Pullman, WA 99164-4820, USA; M3 Biotechnology, Inc., 4000 Mason Rd Suite 300, Box 352141, Seattle, WA 98195-2141, USA
| | - Joseph W Harding
- Departments of Psychology, Integrative Physiology and Neuroscience and Program in Biotechnology, Washington State University, Pullman, WA 99164-4820, USA; M3 Biotechnology, Inc., 4000 Mason Rd Suite 300, Box 352141, Seattle, WA 98195-2141, USA
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21
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Mountford SJ, Albiston AL, Charman WN, Ng L, Holien JK, Parker MW, Nicolazzo JA, Thompson PE, Chai SY. Synthesis, Structure–Activity Relationships and Brain Uptake of a Novel Series of Benzopyran Inhibitors of Insulin-Regulated Aminopeptidase. J Med Chem 2014; 57:1368-77. [DOI: 10.1021/jm401540f] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Simon J. Mountford
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia
| | - Anthony L. Albiston
- College of Health and Biomedicine, Victoria University, St. Albans Campus, St. Albans, Victoria 8001, Australia
| | - William N. Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Leelee Ng
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Jessica K. Holien
- ACRF Rational Drug Discovery Centre and Biota Structural Biology Laboratory, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Michael W. Parker
- ACRF Rational Drug Discovery Centre and Biota Structural Biology Laboratory, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria 3065, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Joseph A. Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Philip E. Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Parkville, Victoria 3052, Australia
| | - Siew Yeen Chai
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
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22
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Wright JW, Kawas LH, Harding JW. A Role for the Brain RAS in Alzheimer's and Parkinson's Diseases. Front Endocrinol (Lausanne) 2013; 4:158. [PMID: 24298267 PMCID: PMC3829467 DOI: 10.3389/fendo.2013.00158] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/09/2013] [Indexed: 12/30/2022] Open
Abstract
The brain renin-angiotensin system (RAS) has available the necessary functional components to produce the active ligands angiotensins II (AngII), angiotensin III, angiotensins (IV), angiotensin (1-7), and angiotensin (3-7). These ligands interact with several receptor proteins including AT1, AT2, AT4, and Mas distributed within the central and peripheral nervous systems as well as local RASs in several organs. This review first describes the enzymatic pathways in place to synthesize these ligands and the binding characteristics of these angiotensin receptor subtypes. We next discuss current hypotheses to explain the disorders of Alzheimer's disease (AD) and Parkinson's disease (PD), as well as research efforts focused on the use of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs), in their treatment. ACE inhibitors and ARBs are showing promise in the treatment of several neurodegenerative pathologies; however, there is a need for the development of analogs capable of penetrating the blood-brain barrier and acting as agonists or antagonists at these receptor sites. AngII and AngIV have been shown to play opposing roles regarding memory acquisition and consolidation in animal models. We discuss the development of efficacious AngIV analogs in the treatment of animal models of AD and PD. These AngIV analogs act via the AT4 receptor subtype which may coincide with the hepatocyte growth factor/c-Met receptor system. Finally, future research directions are described concerning new approaches to the treatment of these two neurological diseases.
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Affiliation(s)
- John W. Wright
- Departments of Psychology, Integrative Physiology and Neuroscience, Program in Biotechnology, Washington State University, Pullman, WA, USA
| | - Leen H. Kawas
- Departments of Psychology, Integrative Physiology and Neuroscience, Program in Biotechnology, Washington State University, Pullman, WA, USA
| | - Joseph W. Harding
- Departments of Psychology, Integrative Physiology and Neuroscience, Program in Biotechnology, Washington State University, Pullman, WA, USA
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23
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Ameliorating effect of new constituents from the hooks of Uncaria rhynchophylla on scopolamine-induced memory impairment. Chin J Nat Med 2013; 11:391-5. [DOI: 10.1016/s1875-5364(13)60057-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Indexed: 11/22/2022]
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24
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Song CZ, Wang QW, Song CC. Diminution of hemoglobin-derived hemorphin: An underlying risk factor for cognitive deficit in diabetes. J Neurol Sci 2012; 317:157-8; author reply 159. [DOI: 10.1016/j.jns.2012.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 03/05/2012] [Indexed: 11/28/2022]
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25
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Wright JW, Harding JW. The brain renin–angiotensin system: a diversity of functions and implications for CNS diseases. Pflugers Arch 2012; 465:133-51. [DOI: 10.1007/s00424-012-1102-2] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 03/20/2012] [Accepted: 03/30/2012] [Indexed: 12/14/2022]
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26
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Albiston AL, Diwakarla S, Fernando RN, Mountford SJ, Yeatman HR, Morgan B, Pham V, Holien JK, Parker MW, Thompson PE, Chai SY. Identification and development of specific inhibitors for insulin-regulated aminopeptidase as a new class of cognitive enhancers. Br J Pharmacol 2012; 164:37-47. [PMID: 21470200 DOI: 10.1111/j.1476-5381.2011.01402.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Two structurally distinct peptides, angiotensin IV and LVV-haemorphin 7, both competitive high-affinity inhibitors of insulin-regulated aminopeptidase (IRAP), were found to enhance aversion-associated and spatial memory in normal rats and to improve performance in a number of memory tasks in rat deficits models. These findings provide compelling support for the development of specific, high-affinity inhibitors of the enzyme as new cognitive enhancing agents. Different classes of IRAP inhibitors have been developed including peptidomimetics and small molecular weight compounds identified through in silico screening with a homology model of the catalytic domain of IRAP. The proof of principal that inhibition of IRAP activity results in facilitation of memory has been obtained by the demonstration that the small-molecule IRAP inhibitors also exhibit memory-enhancing properties.
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Affiliation(s)
- Anthony L Albiston
- Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia
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27
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Wright JW, Harding JW. Brain renin-angiotensin—A new look at an old system. Prog Neurobiol 2011; 95:49-67. [DOI: 10.1016/j.pneurobio.2011.07.001] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 06/27/2011] [Accepted: 07/03/2011] [Indexed: 12/15/2022]
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Andersson H, Demaegdt H, Johnsson A, Vauquelin G, Lindeberg G, Hallberg M, Erdélyi M, Karlén A, Hallberg A. Potent Macrocyclic Inhibitors of Insulin-Regulated Aminopeptidase (IRAP) by Olefin Ring-Closing Metathesis. J Med Chem 2011; 54:3779-92. [DOI: 10.1021/jm200036n] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hanna Andersson
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-751 23 Uppsala, Sweden
| | - Heidi Demaegdt
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Anders Johnsson
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-751 23 Uppsala, Sweden
| | - Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Gunnar Lindeberg
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-751 23 Uppsala, Sweden
| | - Mathias Hallberg
- Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE-751 24 Uppsala, Sweden
| | - Máté Erdélyi
- Department of Chemistry, University of Gothenburg, SE-412 96 Gothenburg, Sweden
- Swedish NMR Centre, University of Gothenburg, Box 465, SE-405 30 Gothenburg, Sweden
| | - Anders Karlén
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-751 23 Uppsala, Sweden
| | - Anders Hallberg
- Department of Medicinal Chemistry, Uppsala University, Box 574, SE-751 23 Uppsala, Sweden
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Gomes I, Dale CS, Casten K, Geigner MA, Gozzo FC, Ferro ES, Heimann AS, Devi LA. Hemoglobin-derived peptides as novel type of bioactive signaling molecules. AAPS JOURNAL 2010; 12:658-69. [PMID: 20811967 DOI: 10.1208/s12248-010-9217-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 06/22/2010] [Indexed: 01/08/2023]
Abstract
Most bioactive peptides are generated by proteolytic cleavage of large precursor proteins followed by storage in secretory vesicles from where they are released upon cell stimulation. Examples of such bioactive peptides include peptide neurotransmitters, classical neuropeptides, and peptide hormones. In the last decade, it has become apparent that the breakdown of cytosolic proteins can generate peptides that have biological activity. A case in point and the focus of this review are hemoglobin-derived peptides. In vertebrates, hemoglobin (Hb) consists of a tetramer of two α- and two β-globin chains each containing a prosthetic heme group, and is primarily involved in oxygen delivery to tissues and in redox reactions (Schechter Blood 112:3927-3938, 2008). The presence of α- and/or β-globin chain in tissues besides red blood cells including rodent and human brain and peripheral tissues (Liu et al. Proc Natl Acad Sci USA 96:6643-6647, 1999; Newton et al. J Biol Chem 281:5668-5676, 2006; Wride et al. Mol Vis 9:360-396, 2003; Setton-Avruj Exp Neurol 203:568-578, 2007; Ohyagi et al. Brain Res 635:323-327, 1994; Schelshorn et al. J Cereb Blood Flow Metab 29:585-595, 2009; Richter et al. J Comp Neurol 515:538-547, 2009) suggests that globins and/or derived peptidic fragments might play additional physiological functions in different tissues. In support of this hypothesis, a number of Hb-derived peptides have been identified and shown to have diverse functions (Ivanov et al. Biopoly 43:171-188, 1997; Karelin et al. Neurochem Res 24:1117-1124, 1999). Modern mass spectrometric analyses have helped in the identification of additional Hb peptides (Newton et al. J Biol Chem 281:5668-5676, 2006; Setton-Avruj Exp Neurol 203:568-578, 2007; Gomes et al. FASEB J 23:3020-3029, 2009); the molecular targets for these are only recently beginning to be revealed. Here, we review the status of the Hb peptide field and highlight recent reports on the identification of a molecular target for a novel set of Hb peptides, hemopressins, and the implication of these peptides to normal cell function and disease. The potential therapeutic applications for these Hb-derived hemopressin peptides will also be discussed.
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Affiliation(s)
- Ivone Gomes
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029, USA
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Albiston AL, Pham V, Ye S, Ng L, Lew RA, Thompson PE, Holien JK, Morton CJ, Parker MW, Chai SY. Phenylalanine-544 plays a key role in substrate and inhibitor binding by providing a hydrophobic packing point at the active site of insulin-regulated aminopeptidase. Mol Pharmacol 2010; 78:600-7. [PMID: 20628006 DOI: 10.1124/mol.110.065458] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Inhibitors of insulin-regulated aminopeptidase (IRAP) improve memory and are being developed as a novel treatment for memory loss. In this study, the binding of a class of these inhibitors to human IRAP was investigated using molecular docking and site-directed mutagenesis. Four benzopyran-based IRAP inhibitors with different affinities were docked into a homology model of the catalytic site of IRAP. Two 4-pyridinyl derivatives orient with the benzopyran oxygen interacting with the Zn(2+) ion and a direct parallel ring-stack interaction between the benzopyran rings and Phe544. In contrast, the two 4-quinolinyl derivatives orient in a different manner, interacting with the Zn(2+) ion via the quinoline nitrogen, and Phe544 contributes an edge-face hydrophobic stacking point with the benzopyran moiety. Mutagenic replacement of Phe544 with alanine, isoleucine, or valine resulted in either complete loss of catalytic activity or altered hydrolysis velocity that was substrate-dependent. Phe544 is also important for inhibitor binding, because these mutations altered the K(i) in some cases, and docking of the inhibitors into the corresponding Phe544 mutant models revealed how the interaction might be disturbed. These findings demonstrate a key role of Phe544 in the binding of the benzopyran IRAP inhibitors and for optimal positioning of enzyme substrates during catalysis.
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Affiliation(s)
- Anthony L Albiston
- Howard Florey Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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31
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Golding BJD, Overall ADJ, Brown G, Gard PR. Strain differences in the effects of angiotensin IV on mouse cognition. Eur J Pharmacol 2010; 641:154-9. [PMID: 20553916 DOI: 10.1016/j.ejphar.2010.05.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 04/27/2010] [Accepted: 05/25/2010] [Indexed: 11/26/2022]
Abstract
Angiotensin IV has been shown to improve learning and memory in rodents. Strain dependent variation in murine behaviour, aminopeptidase activity and inhibitory effect of Angiotensin IV, structural variation in insulin regulated aminopeptidase (IRAP) and aminopeptidase N (ApN) and expression of the encoding genes were explored. Strain differences in the behavioural response to Angiotensin IV were observed, where CD mice were refractory. All strains showed inhibition of aminopeptidase activity by Angiotensin IV but CD mice displayed reduced endogenous aminopeptidase activity. No differences in the coding sequence of IRAP or ApN were found. RT-PCR analysis showed no difference in IRAP expression between strains but an increased expression of ApN was observed in CD mice. The lack of cognitive response of CD mice to Angiotensin IV cannot be explained through variation within IRAP sequence nor expression but the results highlight a potential role for ApN in the effects of Angiotensin IV.
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Affiliation(s)
- Bruno J D Golding
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.
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Albiston AL, Fernando RN, Yeatman HR, Burns P, Ng L, Daswani D, Diwakarla S, Pham V, Chai SY. Gene knockout of insulin-regulated aminopeptidase: Loss of the specific binding site for angiotensin IV and age-related deficit in spatial memory. Neurobiol Learn Mem 2010; 93:19-30. [DOI: 10.1016/j.nlm.2009.07.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 07/27/2009] [Accepted: 07/29/2009] [Indexed: 01/14/2023]
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De Bundel D, Demaegdt H, Lahoutte T, Caveliers V, Kersemans K, Ceulemans AG, Vauquelin G, Clinckers R, Vanderheyden P, Michotte Y, Smolders I. Involvement of the AT1 receptor subtype in the effects of angiotensin IV and LVV-haemorphin 7 on hippocampal neurotransmitter levels and spatial working memory. J Neurochem 2009; 112:1223-34. [PMID: 20028450 DOI: 10.1111/j.1471-4159.2009.06547.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intracerebroventricular (i.c.v.) administration of angiotensin IV (Ang IV) or Leu-Val-Val-haemorphin 7 (LVV-H7) improves memory performance in normal rats and reverses memory deficits in rat models for cognitive impairment. These memory effects were believed to be mediated via the putative 'AT4 receptor'. However, this binding site was identified as insulin-regulated aminopeptidase (IRAP). Correspondingly, Ang IV and LVV-H7 were characterised as IRAP inhibitors. This study investigates whether and how IRAP may be involved in the central effects of Ang IV and LVV-H7. We determined the effects of i.c.v. administration of Ang IV or LVV-H7 on hippocampal neurotransmitter levels using microdialysis in rats. We observed that Ang IV modulates hippocampal acetylcholine levels, whereas LVV-H7 does not. This discrepancy was reflected in the observation that Ang IV binds with micromolar affinity to the AT1 receptor whereas no binding affinity was observed for LVV-H7. Correspondingly, we demonstrated that the AT1 receptor is involved in the effects of Ang IV on hippocampal neurotransmitter levels and on spatial working memory in a plus maze spontaneous alternation task. However, the AT1 receptor was not involved in the spatial memory facilitating effect of LVV-H7. Finally, we demonstrated that Ang IV did not diffuse to the hippocampus following i.c.v. injection, suggesting an extrahippocampal site of action. We propose that AT1 receptors are implicated in the neurochemical and cognitive effects of Ang IV, whereas LVV-H7 may mediate its effects via IRAP.
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Affiliation(s)
- Dimitri De Bundel
- Research Group Experimental Pharmacology, Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Vrije Universiteit Brussel, Brussels, Belgium
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Wilson WL, Munn C, Ross RC, Harding JW, Wright JW. The role of the AT4 and cholinergic systems in the Nucleus Basalis Magnocellularis (NBM): Effects on spatial memory. Brain Res 2009; 1272:25-31. [DOI: 10.1016/j.brainres.2009.03.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 02/19/2009] [Accepted: 03/09/2009] [Indexed: 10/21/2022]
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Vanderheyden PML. From angiotensin IV binding site to AT4 receptor. Mol Cell Endocrinol 2009; 302:159-66. [PMID: 19071192 DOI: 10.1016/j.mce.2008.11.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 11/03/2008] [Accepted: 11/03/2008] [Indexed: 12/23/2022]
Abstract
One of the fragments of the cardiovascular hormone Angiotensin II incited the interest of several research groups. This 3-8 fragment, denoted as Angiotensin IV (Ang IV) causes a number of distinct biological effects (see Introduction), unlikely to be explained by its weak binding to AT(1) and/or AT(2) receptors. Moreover the discovery of high affinity [(125)I]-Ang IV binding sites and their particular tissue distribution led to the concept of the AT(4) receptor. An important breakthrough was achieved by defining the AT(4) receptor as the membrane-bound insulin-regulated aminopeptidase (IRAP). Crucial for the definition as a receptor the binding of the endogenous ligand(s) should be linked to particular cellular and/or biochemical processes. With this respect, cultured cells offer the possibility to study the presence of binding sites in conjunction with ligand induced signaling. This link is discussed for the AT(4) receptor by providing an overview of the cellular effects by AT(4) ligands.
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Affiliation(s)
- Patrick M L Vanderheyden
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium.
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De Bundel D, Smolders I, Vanderheyden P, Michotte Y. Ang II and Ang IV: unraveling the mechanism of action on synaptic plasticity, memory, and epilepsy. CNS Neurosci Ther 2009; 14:315-39. [PMID: 19040556 DOI: 10.1111/j.1755-5949.2008.00057.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The central angiotensin system plays a crucial role in cardiovascular regulation. More recently, angiotensin peptides have been implicated in stress, anxiety, depression, cognition, and epilepsy. Angiotensin II (Ang II) exerts its actions through AT(1) and AT(2) receptors, while most actions of its metabolite Ang IV were believed to be independent of AT(1) or AT(2) receptor activation. A specific binding site with high affinity for Ang IV was discovered and denominated "AT(4) receptor". The beneficiary effects of AT(4) ligands in animal models for cognitive impairment and epileptic seizures initiated the search for their mechanism of action. This proved to be a challenging task, and after 20 years of research, the nature of the "AT(4) receptor" remains controversial. Insulin-regulated aminopeptidase (IRAP) was first identified as the high-affinity binding site for AT(4) ligands. Recently, the hepatocyte growth factor receptor c-MET was also proposed as a receptor for AT(4) ligands. The present review focuses on the effects of Ang II and Ang IV on synaptic transmission and plasticity, learning, memory, and epileptic seizure activity. Possible interactions of Ang IV with the classical AT(1) and AT(2) receptor subtypes are evaluated, and other potential mechanisms by which AT(4) ligands may exert their effects are discussed. Identification of these mechanisms may provide a valuable target in the development in novel drugs for the treatment of cognitive disorders and epilepsy.
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Affiliation(s)
- Dimitri De Bundel
- Research Group Experimental Pharmacology, Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Vrije Universiteit Brussel, Brussels, Belgium
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38
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Protective effect of candesartan in experimental ischemic stroke in the rat mediated by AT2 and AT4 receptors. J Hypertens 2008; 26:2008-15. [PMID: 18806625 DOI: 10.1097/hjh.0b013e32830dd5ee] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES The contribution of the AT2 and AT4 angiotensin receptors to the protective role of the AT1 receptor blocker candesartan in acute ischemic stroke was investigated. METHODS Embolic stroke was induced by injection of calibrated microspheres (50 microm) in the right internal carotid in Sprague-Dawley rats. RESULTS Inhibition of production of endogenous angiotensins by pretreatment for 24 h with lisinopril significantly increased mortality and infarct volume, whereas candesartan for 24 h reduced blood pressure to the same extent but had no deleterious effect. A more sustained pretreatment with candesartan for 5 days significantly decreased mortality, neurological deficit and infarct size. The AT2 receptor antagonist PD123319 and the AT4 receptor antagonist divalinal abolished the protective effect of 5 days' AT1 blockade. Combined blockade of AT2 and AT4 in candesartan pretreated rats resulted in an increased mortality, neurological deficit and infarct volume of similar magnitude to lisinopril pretreatment. Coadministration of lisinopril 24 h before surgery completely blunted the protective effect of candesartan pretreatment. Administration of exogenous angiotensin IV (1 nmol) reversed the deleterious effect of lisinopril pretreatment. CONCLUSION Protection against acute cerebral ischemia induced by AT1 blockade for 5 days is blood pressure independent and mediated by both AT2 and AT4 angiotensin receptors.
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Chai SY, Yeatman HR, Parker MW, Ascher DB, Thompson PE, Mulvey HT, Albiston AL. Development of cognitive enhancers based on inhibition of insulin-regulated aminopeptidase. BMC Neurosci 2008; 9 Suppl 2:S14. [PMID: 19090987 PMCID: PMC2604898 DOI: 10.1186/1471-2202-9-s2-s14] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The peptides angiotensin IV and LVV-hemorphin 7 were found to enhance memory in a number of memory tasks and reverse the performance deficits in animals with experimentally induced memory loss. These peptides bound specifically to the enzyme insulin-regulated aminopeptidase (IRAP), which is proposed to be the site in the brain that mediates the memory effects of these peptides. However, the mechanism of action is still unknown but may involve inhibition of the aminopeptidase activity of IRAP, since both angiotensin IV and LVV-hemorphin 7 are competitive inhibitors of the enzyme. IRAP also has another functional domain that is thought to regulate the trafficking of the insulin-responsive glucose transporter GLUT4, thereby influencing glucose uptake into cells. Although the exact mechanism by which the peptides enhance memory is yet to be elucidated, IRAP still represents a promising target for the development of a new class of cognitive enhancing agents.
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Affiliation(s)
- Siew Yeen Chai
- Howard Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
- Centre for Neuroscience, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Holly R Yeatman
- Howard Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
- Centre for Neuroscience, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Michael W Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
- St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - David B Ascher
- St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Philip E Thompson
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Hayley T Mulvey
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Anthony L Albiston
- Howard Florey Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
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John H, John S, Forssmann WG. Kinetic studies on aminopeptidase M-mediated degradation of human hemorphin LVV-H7 and its N-terminally truncated products. J Pept Sci 2008; 14:797-803. [PMID: 18236385 DOI: 10.1002/psc.1002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The human hemorphin LVV-H7 belongs to the class of micro-opiod receptor-binding peptides, which also exhibits significant affinity to insulin-regulated aminopeptidase (IRAP) thereby affecting IRAP inhibition. The inhibitory potency towards IRAP is of pharmaceutical interest for the treatment of Alzheimer's disease. Consecutive N-terminal cleavage of the first two amino acid residues of LVV-H7 affects a drastic increase of the binding affinity (V-H7) but ultimately leads to its complete abolition after cleavage of the next amino acid residue (H7). Therefore, we investigated LVV-H7 truncation by aminopeptidase M (AP-M) identified as a LVV-H7 degrading enzyme potentially regulating hemorphin activity towards IRAP in vivo. Using a selective quantitative multi-component capillary zone electrophoretic method (CZE-UV), we analyzed the AP-M-mediated subsequent proteolysis of the hemorphins LVV-H7 (L32-F41), VV-H7 (V33-F41), and V-H7 (V34-F41) in vitro. Incubations were carried out with synthetic hemorphins applied as single substrates or in combination. Maximum velocities (V(max)), catalytic constants (turnover numbers, kcat), and specific enzyme activities (EA) were calculated. L32 cleavage from LVV-H7 happens more than two-times faster (kcat: 140 min(-1) +/- 9%, EA: 1.0 U/mg +/- 9%) than V33 cleavage from VV-H7 (kcat: 61 min(-1) +/- 10%, EA: 0.43 U/mg +/- 10%) or V32 deletion from V-H7 (kcat: 62 min(-1) +/- 8%, EA: 0.46 U/mg +/- 8%). In contrast, we showed that H7 (Y35-F41) was neither degraded by porcine AP-M nor did it act as an inhibitor for this enzyme. Determined turnover numbers were in the same dimension as those reported for dynorphin degradation. This is the first time that AP-M-mediated truncation of natural underivatized LVV-H7 and its physiological metabolites was analyzed to determine kinetic parameters useful for understanding hemorphin processing and designing hemorphin-derived drug candidates.
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Affiliation(s)
- Harald John
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Str. 31, Hannover, Germany.
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Abstract
The wealth of information accessible on the molecular level after completion of sequencing of the human and other genomes and in conjunction with new high-throughput technologies like microarrays has paved the way for research on whole systems rather than on single components. Here we describe exemplarily the construction of a rather complex molecular network involved in alcohol addiction by using information from DNA-microarray studies in alcohol-dependent animals. In this network, haemoglobin downregulation in different parts of the brain reward system plays a central role in affecting synaptic plasticity, circadian rhythmicity and opioid receptors. Furthermore, we discuss the dynamic aspect of biological systems with respect to repeated and intermittent drug intake. This aspect can best be captured by the allostatic model on the molecular level. Using a molecular oscillator model where levels of oscillations are changed by repetitive drug administration, changes in set point adjustment are described that underlay allostatic shifts in drug reinforcement processes.
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Affiliation(s)
- Peter J Gebicke-Haerter
- Department of Psychopharmacology, Central Institute of Mental Health, University of Heidelberg, Germany.
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Albiston AL, Morton CJ, Ng HL, Pham V, Yeatman HR, Ye S, Fernando RN, De Bundel D, Ascher DB, Mendelsohn FAO, Parker MW, Chai SY. Identification and characterization of a new cognitive enhancer based on inhibition of insulin‐regulated aminopeptidase. FASEB J 2008; 22:4209-17. [DOI: 10.1096/fj.08-112227] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Anthony L. Albiston
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
| | - Craig J. Morton
- St. Vincent's Institute of Medical ResearchFitzroyVictoriaAustralia
| | - Hooi Ling Ng
- St. Vincent's Institute of Medical ResearchFitzroyVictoriaAustralia
| | - Vi Pham
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
| | - Holly R. Yeatman
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
| | - Siying Ye
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
- Department of PhysiologyDartmouth Medical SchoolHanoverNHUSA
| | - Ruani N. Fernando
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
- Division of Molecular Neurobiology, Department of Medical Biochemistry and BiophysicsKarolinska InstituteStockholmSweden
| | - Dimitri De Bundel
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
- Research Group of Experimental Phar macology, Department of Pharmaceutical Chemistry, Drug Analysis and Drug InformationVrije UniversityBrusselBrusselsBelgium
| | - David B. Ascher
- St. Vincent's Institute of Medical ResearchFitzroyVictoriaAustralia
| | | | - Michael W. Parker
- Department of Biochemistry and Molecular BiologyBio21 Molecular Science and Biotechnology InstituteParkvilleVictoriaAustralia
- St. Vincent's Institute of Medical ResearchFitzroyVictoriaAustralia
| | - Siew Yeen Chai
- Howard Florey Institute, Florey Neurosciences InstitutesParkvilleVictoriaAustralia
- Centre for NeuroscienceUniversity of MelbourneParkvilleVictoriaAustralia
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Fernando RN, Albiston AL, Chai SY. The insulin-regulated aminopeptidase IRAP is colocalised with GLUT4 in the mouse hippocampus - potential role in modulation of glucose uptake in neurones? Eur J Neurosci 2008; 28:588-98. [DOI: 10.1111/j.1460-9568.2008.06347.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wright JW, Yamamoto BJ, Harding JW. Angiotensin receptor subtype mediated physiologies and behaviors: new discoveries and clinical targets. Prog Neurobiol 2008; 84:157-81. [PMID: 18160199 PMCID: PMC2276843 DOI: 10.1016/j.pneurobio.2007.10.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 08/17/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
Abstract
The renin-angiotensin system (RAS) mediates several classic physiologies including body water and electrolyte homeostasis, blood pressure, cyclicity of reproductive hormones and sexual behaviors, and the regulation of pituitary gland hormones. These functions appear to be mediated by the angiotensin II (AngII)/AT(1) receptor subtype system. More recently, the angiotensin IV (AngIV)/AT(4) receptor subtype system has been implicated in cognitive processing, cerebroprotection, local blood flow, stress, anxiety and depression. There is accumulating evidence to suggest an inhibitory influence by AngII acting at the AT(1) subtype, and a facilitory role by AngIV acting at the AT(4) subtype, on neuronal firing rate, long-term potentiation, associative and spatial learning, and memory. This review initially describes the biochemical pathways that permit synthesis and degradation of active angiotensin peptides and three receptor subtypes (AT(1), AT(2) and AT(4)) thus far characterized. There is vigorous debate concerning the identity of the most recently discovered receptor subtype, AT(4). Descriptions of classic and novel physiologies and behaviors controlled by the RAS are presented. This review concludes with a consideration of the emerging therapeutic applications suggested by these newly discovered functions of the RAS.
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Affiliation(s)
- John W Wright
- Department of Psychology, Washington State University, P.O. Box 644820, Pullman, WA 99164-4820, USA.
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Involvement of insulin-regulated aminopeptidase in the effects of the renin–angiotensin fragment angiotensin IV: a review. Heart Fail Rev 2007; 13:321-37. [DOI: 10.1007/s10741-007-9062-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
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46
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Albiston AL, Peck GR, Yeatman HR, Fernando R, Ye S, Chai SY. Therapeutic targeting of insulin-regulated aminopeptidase: heads and tails? Pharmacol Ther 2007; 116:417-27. [PMID: 17900701 DOI: 10.1016/j.pharmthera.2007.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 07/30/2007] [Indexed: 10/22/2022]
Abstract
Insulin-regulated aminopeptidase, IRAP, is an abundant protein that was initially cloned from a rat epididymal fat pad cDNA library as a marker protein for specialized vesicles containing the insulin-responsive glucose transporter GLUT4, wherein it is thought to participate in the tethering and trafficking of GLUT4 vesicles. The same protein was independently cloned from human placental cDNA library as oxytocinase and is proposed to have a primary role in the regulation of circulating oxytocin (OXY) during the later stages of pregnancy. More recently, IRAP was identified as the specific binding site for angiotensin IV, and we propose that it mediates the memory-enhancing effects of the peptide. This protein appears to have multiple physiological roles that are tissue- and domain-specific; thus the protein can be specifically targeted for treating different clinical conditions.
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Affiliation(s)
- Anthony L Albiston
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria 3010, Australia
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John H, Schulz S, Forssmann WG. Comparative in vitro degradation of the human hemorphin LVV-H7 in mammalian plasma analysed by capillary zone electrophoresis and mass spectrometry. Biopharm Drug Dispos 2007; 28:73-85. [PMID: 17173283 DOI: 10.1002/bdd.533] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The human hemorphin LVV-H7 (L32VVYPWTQRF41) is a hemoglobin-beta, -gamma, -delta or -epsilon chain derived cationic decapeptide of the micro-opioid receptor binding family. It exhibits potential pharmacological value relevant, for example, for blood pressure regulation, learning performance and Alzheimer's disease. The regulatory potency is strictly dependent on the length of the amino acid sequence which is sensitive towards proteinases from tissues and plasma. To analyse LVV-H7 in vitro degradation in mammalian plasma, a novel multi-component quantitative capillary zone electrophoretic (CZE) procedure was applied, combined with qualitative metabolite profiling by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In all types of plasma, LVV-H7 was N-terminally truncated generating four metabolites (M1-M4) with an intact C-terminus: M1 (V33VYPWTQRF41), M2 (V34YPWTQRF41), M3 (Y35PWTQRF41) and M4 (W37TQRF41). In EDTA plasma these degradation products were detected exclusively, whereas in citrate and heparin plasma four further metabolites appeared resulting from additional C-terminal cleavage of the dipeptide R40F41: M5 (L32VVYPWTQ39), M6 (V33VYPWTQ39), M7 (V34YPWTQ39) and M8 (Y35PWTQ39). In the presence of selective proteinase inhibitors aminopeptidase M and angiotensin-converting enzyme (for N- and C-terminal truncation, respectively) were identified as plasma enzymes responsible for hemorphin degradation. Furthermore, striking inter-mammalian species distinctions were detected revealing strongly differing degradation velocities but similar metabolite patterns.
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Affiliation(s)
- Harald John
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Str. 31, Hannover, Germany.
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Ferreira PM, Souza Dos Santos RA, Campagnole-Santos MJ. Angiotensin-(3-7) pressor effect at the rostral ventrolateral medulla. ACTA ACUST UNITED AC 2007; 141:168-74. [PMID: 17350116 DOI: 10.1016/j.regpep.2006.12.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 12/21/2006] [Accepted: 12/27/2006] [Indexed: 11/22/2022]
Abstract
Ang-(3-7) is a fragment of the renin-angiotensin system that can be derived both from Ang II or Ang-(1-7). In the present study we determined the cardiovascular effects produced by angiotensin-(3-7) [Ang-(3-7)] microinjection into the rostral ventrolateral medulla (RVLM), a key region for the control of sympathetic drive to the periphery. RVLM microinjection of Ang-(3-7) (20, 40 or 80 ng) in male Wistar rats anesthetized with urethane produced significant increases in MAP (19+/-3.8 mm Hg, n=5; 16+/-1.6 mm Hg, n=15 and 11+/-1.2 mm Hg, n=4, respectively) as compared to saline (4+/-0.7 mm Hg, n=6). These alterations were similar to that induced by Ang-(1-7) (14+/-1.3 mm Hg, 40 ng; n=12) and Ang II (17+/-2.3 mm Hg, 40 ng; n=7). Microinjection of losartan (AT(1) receptor antagonist, 100 pmol) or A779 (selective Mas receptor antagonist, 100 pmol) did not alter the pressor effect caused by Ang-(3-7). Microinjection of an Ang-(3-7) analogue, d-Ala(7)-Ang-(3-7) (100 pmol), completely abolished the pressor effect caused by Ang-(3-7). These results suggest that Ang-(3-7) may be an additional peptide of the RAS to act as neuromodulator, at least at the RVLM. Further, the Ang-(3-7) pressor effect is not mediated by the interaction with AT(1) or the Ang-(1-7), Mas, receptors.
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Affiliation(s)
- Patrícia Maria Ferreira
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901 MG, Brazil
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Ye S, Chai SY, Lew RA, Albiston AL. Insulin-regulated aminopeptidase: analysis of peptide substrate and inhibitor binding to the catalytic domain. Biol Chem 2007; 388:399-403. [PMID: 17391061 DOI: 10.1515/bc.2007.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Peptide inhibitors of insulin-regulated aminopeptidase (IRAP) accelerate spatial learning and facilitate memory retention and retrieval by binding competitively to the catalytic site of the enzyme and inhibiting its catalytic activity. IRAP belongs to the M1 family of Zn2+-dependent aminopeptidases characterized by a catalytic domain that contains two conserved motifs, the HEXXH(X)18E Zn2+-binding motif and the GXMEN exopeptidase motif. To elucidate the role of GXMEN in binding peptide substrates and competitive inhibitors, site-directed mutagenesis was performed on the motif. Non-conserved mutations of residues G428, A429 and N432 resulted in mutant enzymes with altered catalytic activity, as well as divergent changes in kinetic properties towards the synthetic substrate leucine beta-naphthylamide. The affinities of the IRAP inhibitors angiotensin IV, Nle1-angiotensin IV, and LVV-hemorphin-7 were selectively decreased. Substrate degradation studies using the in vitro substrates vasopressin and Leu-enkephalin showed that replacement of G428 by either D, E or Q selectively abolished the catalysis of Leu-enkephalin, while [A429G]IRAP and [N432A]IRAP mutants were incapable of cleaving both substrates. These mutational studies indicate that G428, A429 and N432 are important for binding of both peptide substrates and inhibitors, and confirm previous results demonstrating that peptide IRAP inhibitors competitively bind to its catalytic site.
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Affiliation(s)
- Siying Ye
- Howard Florey Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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John H, Schulz S, Forssmann WG. Validated multi-component CZE-UV procedure for the quantification of human hemorphin LVV-H7 in plasma stability studies. Anal Bioanal Chem 2006; 386:235-43. [PMID: 16838155 DOI: 10.1007/s00216-006-0624-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 06/07/2006] [Accepted: 06/14/2006] [Indexed: 10/24/2022]
Abstract
The human hemorphin LVV-H7 is an endogenous cleavage product of the hemoglobin beta, gamma, epsilon or delta chain exhibiting potential pharmaceutical relevance for blood pressure regulation, the treatment of Alzheimer's disease or learning deficiencies. Here we present the development of a multi-component capillary zone electrophoretic method (CZE-UV), allowing the simultaneous quantification of LVV-H7 and four N-terminal degradation products generated in EDTA plasma. Hemorphins in the supernatant of precipitated plasma samples are quantified by external calibration. Validation of the procedure oriented towards international pharmaceutical guidelines and demonstrated excellent linearity (r2 > or = 0.999), good precision (repeatability and reproducibility below 11%), accuracy (-8.4%-4%), ruggedness and an appropriate lower limit of quantification (LLOQ 1.0 microg mL(-1)). This procedure was applied to stability studies of LVV-H7 in human EDTA plasma attended by profiling metabolites using qualitative MALDI-TOF MS analysis. We detected the activity of a soluble plasma form of aminopeptidase M causing successive N-terminal truncation. This is the first time that LVV-H7 degradation as well as its metabolite production have systematically been monitored by a quantitative CZE-UV procedure, underlining the growing importance of such techniques in peptide analysis. In addition, our results give useful hints for future drug development of LVV-H7.
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Affiliation(s)
- Harald John
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Strasse 31, 30627 Hannover, Germany.
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