1
|
Affiliation(s)
- Davia Prischich
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Alexandre M. J. Gomila
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | | | - Gemma Sangüesa
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Rebeca Diez‐Alarcia
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Beatrice Preda
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Montserrat Batlle
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Laura Ramírez
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
| | - Ernest Giralt
- Department of Inorganic and Organic Chemistry University of Barcelona (UB) Barcelona Spain
- Institute for Research in Biomedicine (IRB) Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Jordi Hernando
- Departament de Química Universitat Autònoma de Barcelona (UAB) Cerdanyola del Vallès Spain
| | - Eduard Guasch
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - J. Javier Meana
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Pedro Villa
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) Madrid Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
| |
Collapse
|
2
|
Adrenergic Modulation With Photochromic Ligands. Angew Chem Int Ed Engl 2020; 60:3625-3631. [DOI: 10.1002/anie.202010553] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/21/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Davia Prischich
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Alexandre M. J. Gomila
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | | | - Gemma Sangüesa
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Rebeca Diez‐Alarcia
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Beatrice Preda
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
| | - Montserrat Batlle
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - Laura Ramírez
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
| | - Ernest Giralt
- Department of Inorganic and Organic Chemistry University of Barcelona (UB) Barcelona Spain
- Institute for Research in Biomedicine (IRB) Barcelona Institute for Science and Technology (BIST) Barcelona Spain
| | - Jordi Hernando
- Departament de Química Universitat Autònoma de Barcelona (UAB) Cerdanyola del Vallès Spain
| | - Eduard Guasch
- Institut Clínic Cardiovascular Hospital Clinic University of Barcelona (UB), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
- Centro de Investigación Biomédica en Red— Enfermedades Cardiovasculares (CIBER-CV) Spain
| | - J. Javier Meana
- Department of Pharmacology University of the Basque Country (UPV/EHU) Leioa Bizkaia Spain
- Centro de Investigación Biomédica en Red— Salud Mental (CIBER-SAM) Spain
| | - Pedro Villa
- Department of Systems Biology University of Alcalá (UAH) Madrid Spain
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS) Madrid Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC) The Barcelona Institute for Science and Technology (BIST) Barcelona Spain
- Centro de Investigación Biomédica en Red— Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) Spain
- Catalan Institution for Research and Advanced Studies (ICREA) Barcelona Spain
| |
Collapse
|
3
|
Marsdenia tenacissima extract dilated small mesenteric arteries via stimulating endothelial nitric oxide synthase and inhibiting calcium influx. JOURNAL OF ETHNOPHARMACOLOGY 2019; 238:111847. [PMID: 30946966 DOI: 10.1016/j.jep.2019.111847] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/19/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Marsdenia tenacissima is a traditional Chinese medicine that is known to be effective in combating cancer as well as reducing blood pressure. The efficacy and mechanisms of Marsdenia tenacissima in treating cancer have been well described. However, the potential vasoactivities of Marsdenia tenacissima remain poorly known. AIM OF THE STUDY To determine the vasoactive effects of the water-soluble part of marsdenia tenacissima in mesenteric resistance arteries of the mice, and to explore the underlying mechanisms. MATERIALS AND METHODS Isometric vessel tension study was used to examine the effects of marsdenia tenacissima extract (MTE) on vasodilation of the mesenteric arteries of mice. KCl, phenylephrine (PE) and 9,11-Dideoxy-11α,9α-epoxymethanoprostaglandin F2α (U46619) were used as vasoconstrictors. Y27632, Nitro-L-arginine methyl ester hydrochloride (L-NAME) and indomethacin were used to explore the underlying mechanisms for the vasoactivities of MTE. Western blot and nitric oxide (NO) assay were used to evaluate the effects of MTE on the activities of endothelial nitric oxide synthase (eNOS). RESULTS MTE (5-50 mg/mL), but not vehicle, dose-dependently relaxed the mesenteric arteries constricted with KCl, PE or U46619, in which relaxations to KCl were more pronounced than that to PE or U46619. Pre-incubation of the vessels with MTE (40 mg/mL) reduced the vasoconstrictions caused by calcium influx. Decreasing calcium sensitivity by inhibition of Rho kinase (ROCK) significantly augmented the vasorelaxation of MTE. While, inhibition of endothelial cells by pre-incubation with L-NAME (300 μM) and indomethacin (10 μM) or denudating endothelial cells attenuated vasorelaxations of MTE to KCl, and with a larger potency, to U46619. In both human umbilical vein endothelial cells (HUVECs) and human heart microvascular endothelial cells (HMECs), the phosphorylations of eNOS and the production of NO were significantly enhanced after treatment of MTE for 2, 5, 10, 30 min. CONCLUSIONS MTE, the water-soluble part of marsdenia tenacissima, was effective in relaxing mesenteric resistance arteries via inhibiting calcium influx and stimulating eNOS activities.
Collapse
Affiliation(s)
- Huifeng Hao
- Department of Integration of Chinese and Western Medicine, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Peking University Cancer Hospital & Institute, Beijing, 100142, PR China
| | - Wenjia Tian
- Department of Gastroenterology, Peking University International Hospital, Beijing, 102206, PR China
| | - Chunshui Pan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, 100191, PR China
| | - Yanna Jiao
- Department of Integration of Chinese and Western Medicine, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Peking University Cancer Hospital & Institute, Beijing, 100142, PR China
| | - Xinxin Deng
- Ningxia Medical University Pharmacy College, Key Laboratory of Hui Ethnic Medicine Modernization, Ministry of Education, Ningxia Research Center of Modern Hui Medicine Engineering and Technology, Yinchuan, 750004, PR China
| | - Jingyu Fan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, 100191, PR China
| | - Jingyan Han
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, 100191, PR China; Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, 100191, PR China
| | - Shuyan Han
- Department of Integration of Chinese and Western Medicine, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Peking University Cancer Hospital & Institute, Beijing, 100142, PR China.
| | - Miao Wang
- State Key Laboratory of Cardiovascular Disease, and Clinical Pharmacology Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
| | - Pingping Li
- Department of Integration of Chinese and Western Medicine, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Peking University Cancer Hospital & Institute, Beijing, 100142, PR China.
| |
Collapse
|
4
|
Variations in Chemical Composition, Vasorelaxant and Angiotensin I-Converting Enzyme Inhibitory Activities of Essential Oil from Aerial Parts ofSeseli pallasiiBesser(Apiaceae). Chem Biodivers 2017; 14. [DOI: 10.1002/cbdv.201600407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 11/24/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Relja Suručić
- Department of Pharmacognosy; University of Banja Luka-Faculty of Medicine; Save Mrkalja 14 78000 Banjaluka Bosnia and Herzegovina
| | - Tatjana Kundaković
- Department of Pharmacognosy; University of Belgrade-Faculty of Pharmacy; V.Stepe 450 Belgrade Serbia
| | - Branislava Lakušić
- Department of Botany; University of Belgrade-Faculty of Pharmacy; V.Stepe 450 Belgrade Serbia
| | - Dragana Drakul
- Faculty of Medicine; University of Eastern Sarajevo; Studentska 7 Foča Bosnia and Herzegovina
| | - Slobodan R. Milovanović
- Faculty of Medicine; University of Eastern Sarajevo; Studentska 7 Foča Bosnia and Herzegovina
| | - Nada Kovačević
- Department of Pharmacognosy; University of Belgrade-Faculty of Pharmacy; V.Stepe 450 Belgrade Serbia
| |
Collapse
|
5
|
Abstract
In addition to cell surface membranes, numerous G protein-coupled receptors (GPCRs) are located on intracellular membranes including the nuclear envelope. Although the role of numerous GPCRs at the cell surface has been well characterized, the physiological function of these same receptors located on intracellular membranes remains to be determined. Here, we employ a novel caged Ang-II analog, cAng-II, to compare the effects of the activation of cell surface versus intracellular angiotensin receptors in intact cardiomyocytes. When added extracellularly to HEK 293 cells, Ang-II and photolysed cAng-II increased ERK1/2 phosphorylation (via AT1R) and cGMP production (AT2R). In contrast unphotolysed cAng-II did not. Cellular uptake of cAng-II was 6-fold greater than that of Ang-II and comparable to the HIV TAT(48-60) peptide. Intracellular photolysis of cAng-II induced an increase in nucleoplasmic Ca(2+) ([Ca(2+)]n) that was greater than that induced by extracellular application of Ang-II. We conclude that cell-permeable ligands that can access intracellular GPCRs may evoke responses distinct from those with access restricted to the same receptor located on the cell surface.
Collapse
Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada
| | | | - Alain Fournier
- INRS-Institut Armand-Frappier, Université du Québec, Canada; Laboratoire International Associé Samuel de Champlain, Canada
| | - David Chatenet
- INRS-Institut Armand-Frappier, Université du Québec, Canada; Laboratoire International Associé Samuel de Champlain, Canada
| | - Stanley Nattel
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada; Department of Pharmacology and Therapeutics, McGill University, Canada.
| | - Bruce G Allen
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada; Department of Pharmacology and Therapeutics, McGill University, Canada; Department of Biochemistry and Molecular Medicine, Université de Montréal, Canada.
| |
Collapse
|
6
|
Photoreconfigurable Physically Cross-Linked Triblock Copolymer Hydrogels: Photodisintegration Kinetics and Structure–Property Relationships. Macromolecules 2015. [DOI: 10.1021/ma502372f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Christopher J. Bettinger
- McGowan Institute
of Regenerative Medicine, 450 Technology
Drive, Suite 300, Pittsburgh, Pennsylvania 15219, United States
| |
Collapse
|
7
|
Photoreleasable ligands to study intracrine angiotensin II signalling. J Physiol 2015; 593:521-39. [PMID: 25433071 DOI: 10.1113/jphysiol.2014.279109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 11/20/2014] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS The renin-angiotensin system plays a key role in cardiovascular physiology and its overactivation has been implicated in the pathogenesis of several major cardiovascular diseases. There is growing evidence that angiotensin II (Ang-II) may function as an intracellular peptide to activate intracellular/nuclear receptors and their downstream signalling effectors independently of cell surface receptors. Current methods used to study intracrine Ang-II signalling are limited to indirect approaches because of a lack of selective intracellularly-acting probes. Here, we present novel photoreleasable Ang-II analogues used to probe intracellular actions with spatial and temporal precision. The photorelease of intracellular Ang-II causes nuclear and cytosolic calcium mobilization and initiates the de novo synthesis of RNA in cardiac cells, demonstrating the application of the method. ABSTRACT Several lines of evidence suggest that intracellular angiotensin II (Ang-II) contributes to the regulation of cardiac contractility, renal salt reabsorption, vascular tone and metabolism; however, work on intracrine Ang-II signalling has been limited to indirect approaches because of a lack of selective intracellularly-acting probes. Here, we aimed to synthesize and characterize cell-permeant Ang-II analogues that are inactive without uncaging, but release active Ang-II upon exposure to a flash of UV-light, and act as novel tools for use in the study of intracrine Ang-II physiology. We prepared three novel caged Ang-II analogues, [Tyr(DMNB)(4)]Ang-II, Ang-II-ODMNB and [Tyr(DMNB)(4)]Ang-II-ODMNB, based upon the incorporation of the photolabile moiety 4,5-dimethoxy-2-nitrobenzyl (DMNB). Compared to Ang-II, the caged Ang-II analogues showed 2-3 orders of magnitude reduced affinity toward both angiotensin type-1 (AT1R) and type-2 (AT2R) receptors in competition binding assays, and greatly-reduced potency in contraction assays of rat thoracic aorta. After receiving UV-irradiation, all three caged Ang-II analogues released Ang-II and potently induced the contraction of rat thoracic aorta. [Tyr(DMNB)(4)]Ang-II showed the most rapid photolysis upon UV-irradiation and was the focus of subsequent characterization. Whereas Ang-II and photolysed [Tyr(DMNB)(4)]Ang-II increased ERK1/2 phosphorylation (via AT1R) and cGMP production (AT2R), caged [Tyr(DMNB)(4)]Ang-II did not. Cellular uptake of [Tyr(DMNB)(4)]Ang-II was 4-fold greater than that of Ang-II and significantly greater than uptake driven by the positive-control HIV TAT(48-60) peptide. Intracellular photolysis of [Tyr(DMNB)(4)]Ang-II induced an increase in nucleoplasmic Ca(2+) ([Ca(2+)]n), and initiated 18S rRNA and nuclear factor kappa B mRNA synthesis in adult cardiac cells. We conclude that caged Ang-II analogues represent powerful new tools for use in the selective study of intracrine signalling via Ang-II.
Collapse
Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada; Montreal Heart Institute, Montréal, Québec, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Relevance of rhodopsin studies for GPCR activation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:674-82. [PMID: 24041646 DOI: 10.1016/j.bbabio.2013.09.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/02/2013] [Accepted: 09/05/2013] [Indexed: 10/26/2022]
Abstract
Rhodopsin, the dim-light photoreceptor present in the rod cells of the retina, is both a retinal-binding protein and a G protein-coupled receptor (GPCR). Due to this conjunction, it benefits from an arsenal of spectroscopy techniques that can be used for its characterization, while being a model system for the important family of Class A (also referred to as "rhodopsin-like") GPCRs. For instance, rhodopsin has been a crucial player in the field of GPCR structural biology. Until 2007, it was the only GPCR for which a high-resolution crystal structure was available, so all structure-activity analyses on GPCRs, from structure-based drug discovery to studies of structural changes upon activation, were based on rhodopsin. At present, about a third of currently available GPCR structures are still from rhodopsin. In this review, I show some examples of how these structures can still be used to gain insight into general aspects of GPCR activation. First, the analysis of the third intracellular loop in rhodopsin structures allows us to gain an understanding of the structural and dynamic properties of this region, which is absent (due to protein engineering or poor electron density) in most of the currently available GPCR structures. Second, a detailed analysis of the structure of the transmembrane domains in inactive, intermediate and active rhodopsin structures allows us to detect early conformational changes in the process of ligand-induced GPCR activation. Finally, the analysis of a conserved ligand-activated transmission switch in the transmembrane bundle of GPCRs in the context of the rhodopsin activation cycle, allows us to suggest that the structures of many of the currently available agonist-bound GPCRs may correspond to intermediate active states. While the focus in GPCR structural biology is inevitably moving away from rhodopsin, in other aspects rhodopsin is still at the forefront. For instance, the first studies of the structural basis of disease mutants in GPCRs, or the most detailed analysis of cellular GPCR signal transduction networks using a systems biology approach, have been carried out in rhodopsin. Finally, due again to its unique properties among GPCRs, rhodopsin will likely play an important role in the application of X-ray free electron laser crystallography to time-resolved structural biology in membrane proteins. Rhodopsin, thus, still remains relevant as a model system to study the molecular mechanisms of GPCR activation. This article is part of a Special Issue entitled: Retinal Proteins-You can teach an old dog new tricks.
Collapse
Affiliation(s)
- Xavier Deupi
- Condensed Matter Theory Group and Laboratory of Biomolecular Research, Paul Scherrer Institute, WHGA/106, CH-5232 Villigen PSI, Switzerland
| |
Collapse
|
9
|
The α,5-dicarboxy-2-nitrobenzyl caging group, a tool for biophysical applications with improved hydrophilicity: synthesis, photochemical properties and biological characterization. Photochem Photobiol 2010; 86:1247-54. [PMID: 20880228 DOI: 10.1111/j.1751-1097.2010.00803.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Earlier we reported on the synthesis of α,4-dicarboxy-2-nitrobenyzl caged compounds (Schaper, K. et al. [2002] Eur. J. Org. Chem., 1037-1046). These compounds have the advantage of an increased hydrophilicity compared with the well-established α-carboxy-2-nitrobenzyl caged compounds; however, the release of the active compound becomes slower due to the introduction of the additional carboxy group. Based upon theoretical calculations we predicted that the release would become faster when the additional carboxy group is moved to the 5-position. Here we describe the synthesis and the photochemical and biological characterization of an α,5-dicarboxy-2-nitrobenyzl caged compound. The high hydrophilicity of the new caging group is maintained due to the fact that the additional carboxy moiety is preserved, while the release of the active species from the new derivative is even faster than for the reference, an α-CNB caged compound.
Collapse
Affiliation(s)
- Klaus Schaper
- Group for Organic Photochemistry, Institute for Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
| | | | | | | |
Collapse
|
10
|
Investigating the degradation of the sympathomimetic drug phenylephrine by electrospray ionisation-mass spectrometry. J Pharm Biomed Anal 2010; 52:203-9. [PMID: 20122809 DOI: 10.1016/j.jpba.2010.01.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 01/05/2010] [Accepted: 01/08/2010] [Indexed: 11/26/2022]
Abstract
The frequently used sympathomimetic drug phenylephrine has been studied by electrospray ionisation-mass spectrometry. The stability of the adrenoceptor agonist was examined by investigations of the pharmaceutically used salts phenylephrine hydrochloride and phenylephrine bitartrate. Photostability has been studied by use of an irradiation equipment emitting a solar radiation spectrum. The experiments were carried out by analysis of aqueous drug solutions before and after irradiation treatment. The phenylephrine derivative with unsaturated side chain originating from the drug by loss of one water molecule has been detected as the major degradation product of both phenylephrine salts the hydrochloride and the bitartrate. Further degradation and oxidation products were detectable already in the full scan mode demonstrating a low stability of the drug. Tandem mass spectrometry and multiple stage mass spectrometry experiments enabled the establishment of fragmentation schemes of both salts for the first time. Irradiation treatment indicated that phenylephrine bitartrate is more prone to degradation than the hydrochloride because of an additional decomposition sensitivity of the tartaric acid counter ion. An interaction between phenylephrine and its counter ion degradation products via a nucleophilic addition mechanism is suggested to be the explanation for the detected ion signals after irradiation treatment of phenylephrine bitartrate.
Collapse
Affiliation(s)
- Hagen Trommer
- Martin-Luther-University Halle-Wittenberg, School of Pharmacy, Institute of Pharmaceutics and Biopharmaceutics, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle, Saale, Germany.
| | | | | |
Collapse
|
11
|
Abstract
A caged molecule is an inert but photosensitive molecule that is transformed by photolysis into a biologically active molecule at high speed (typically 1 msec). The process is referred to as photorelease. The spatial resolution of photorelease is limited by the properties of light; submicrometer resolution is potentially achievable. Therefore, focal photorelease of caged molecules enables one to control biological processes with high spatio-temporal precision. The principles underlying caged molecules as well as practical considerations for their use are discussed in this unit.
Collapse
Affiliation(s)
- Joseph P Y Kao
- University of Maryland Biotechnology Institute, Baltimore, Maryland, USA
| |
Collapse
|
12
|
Optical switches and triggers for the manipulation of ion channels and pores. MOLECULAR BIOSYSTEMS 2007; 3:686-704. [PMID: 17882331 DOI: 10.1039/b710287a] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Like fluorescence sensing techniques, methods to manipulate proteins with light have produced great advances in recent years. Ion channels have been one of the principal protein targets of photoswitched manipulation. In combination with fluorescence detection of cell signaling, this has enabled non-invasive, all-optical experiments on cell and tissue function, both in vitro and in vivo. Optical manipulation of channels has also provided insights into the mechanism of channel function. Optical control elements can be classified according to their molecular reversibility as non-reversible phototriggers where light breaks a chemical bond (e.g. caged ligands) and as photoswitches that reversibly photoisomerize. Synthetic photoswitches constitute nanoscale actuators that can alter channel function using three different strategies. These include (1) nanotoggles, which are tethered photoswitchable ligands that either activate channels (agonists) or inhibit them (blockers or antagonists), (2) nanokeys, which are untethered (freely diffusing) photoswitchable ligands, and (3) nanotweezers, which are photoswitchable crosslinkers. The properties of such photoswitches are discussed here, with a focus on tethered photoswitchable ligands. The recent literature on optical manipulation of ion channels is reviewed for the different channel families, with special emphasis on the understanding of ligand binding and gating processes, applications in nanobiotechnology, and with attention to future prospects in the field.
Collapse
Affiliation(s)
- Pau Gorostiza
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | | |
Collapse
|
13
|
Rotation frequency of human bronchial and nasal epithelial spheroids as an indicator of mucociliary function. Respiration 2006; 73:664-72. [PMID: 16612049 DOI: 10.1159/000092672] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Accepted: 12/21/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We evaluated a new in vitro model for mucociliary transport function. Spheroids of human respiratory epithelium show beating cilia at their surface. When cultured in their own mucus, spheroids can rotate along their axis due to coordinated ciliary beating. OBJECTIVE AND METHODS To assess whether this setup yields meaningful results we measured rotation frequency (RF) of human bronchial or nasal epithelial spheroids under different temperatures and concentrations of isoproterenol. Isoproterenol was administered either as caged compound releasing active isoproterenol after illumination with UV light, or through a permeable membrane in a two-chamber system. RESULTS Under stable conditions, RF remained constant over 200 min. Between 27 and 35 degrees C, there was a temperature-dependent increase: RF(27)( degrees )(C) = 0.27 +/- 0.08 s(-1), and RF(37)( degrees )(C) = 0.43 +/- 0.10 s(-1) (means +/- SEM). Isoproterenol (10(-5), 10(-4) and 10(-3) mmol/l) induced concentration-dependent increases in RF (9, 20 and 25%, respectively; medians) if applied in the two-chamber system. The experiments with caged isoproterenol did not yield conclusive results, probably because the byproducts from photolysis negatively affected ciliary function. The transport velocity at the surface of bronchial and nasal spheroids was estimated to be 2.96 and 3.62 mm/min (medians), respectively, which is in the same range as mucus transport velocity measured in vivo in humans. CONCLUSIONS This setup can be used to study mucociliary transport function under controlled conditions in vitro, in particular as RF is likely to reflect not only ciliary beat frequency, but also the coordination of ciliary beating and the properties of the mucus.
Collapse
Affiliation(s)
- Fernando Gamarra
- Division of Pneumology, Department of Internal Medicine, University Hospital, Ludwig Maximilian University, Munich, Germany.
| | | | | | | | | | | |
Collapse
|
14
|
Abstract
We present here the synthesis and characterization of four photolabile derivatives of urea in which alpha-substituted 2-nitrobenzyl groups are covalently attached to the urea nitrogen. These derivatives photolyze readily in aqueous solution to release free urea. The alpha-substituents of the 2-nitrobenzyl group strongly influence the rate of the photolysis reaction measured with transient absorption spectroscopy. Rates of photolysis at pH 7.5 and room temperature (approximately 22 degrees C) for N-(2-nitrobenzyl)urea, N-(alpha-methyl-2-nitrobenzyl)urea, N-(alpha-carboxymethyl-2-nitrobenzyl)urea, and N-(alpha-carboxy-2-nitrobenzyl)urea are, respectively, 1.7 x 10(4), 8.5 x 10(4), 4.0 x 10(4), and 1.1 x 10(5) s(-)(1). The quantum yields determined by measurement of free urea following irradiation by a single laser pulse at 308 nm were 0.81 for N-(2-nitrobenzyl)urea, 0.64 for N-(alpha-methyl-2-nitrobenzyl)urea, and 0.56 for N-(alpha-carboxy-2-nitrobenzyl)urea. The caged N-(alpha-carboxy-2-nitrobenzyl)urea is not a substrate of the enzyme urease, while the photolytically released urea is. Also, neither this caged urea nor its photolytic side products inhibit hydrolysis of free urea by urease. Thus, the alpha-carboxy-2-nitrobenzyl derivative of urea is suitable for mechanistic investigations of the enzyme urease.
Collapse
Affiliation(s)
- Raymond Wieboldt
- Molecular Biology and Genetics, 217 Biotechnology Building, Cornell University, Ithaca, New York 14853-2703, USA
| | | | | | | | | | | |
Collapse
|
15
|
|
16
|
Kinetics of contraction in depolarized smooth muscle from guinea-pig taenia coli after photodestruction of nifedipine. J Physiol 1999; 519 Pt 1:213-21. [PMID: 10432352 PMCID: PMC2269492 DOI: 10.1111/j.1469-7793.1999.0213o.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
1. The time course and kinetics of force development following activation by opening of L-type Ca2+ channels was investigated using photodestruction of the Ca2+ channel blocker nifedipine in smooth muscle from the guinea-pig taenia coli. 2. In muscles activated using high K+ and Ca2+ and subsequently inhibited with nifedipine, photodestruction of the drug using a strong ultraviolet light flash initiated a rapid contraction. The force initiated by photodestruction of nifedipine reached near-maximal levels. This procedure eliminates diffusional delays and can thus be used to investigate the kinetics of depolarization-induced contractions. 3. The rate of force development of contractions initiated by photodestruction of nifedipine was slower than that observed in maximally thiophosphorylated skinned fibres. This suggests the rate of force development is limited by activation steps in the activation cascade prior to the force generation of the cross-bridge system. 4. The rate of force development and the plateau force were dependent on the extracellular [CaCl2] suggesting that the intracellular [Ca2+] determines the rate of phosphorylation and force development. The delay between illumination and increase in force was about 300 ms. The delay was similar at low and high extracellular [CaCl2] indicating that buffering by superficial sarcoplasmatic reticulum does not introduce a delay in force development following activation of Ca2+ channels in this muscle.
Collapse
Affiliation(s)
- U Malmqvist
- Department of Physiology and Neuroscience, University of Lund, Sweden.
| | | |
Collapse
|
17
|
Abstract
A number of new 'caged' intracellular second messengers and neurotransmitters have been developed using the photolabile o-nitrobenzyl group. This chemistry has also recently been exploited in novel ways, including the development of caged enzyme substrates and caged proteins. Although caged compounds continue to be used primarily for mechanistic (kinetic) studies of processes mediated by transmitters or second messengers, the spatial resolution afforded by the use of light to effect changes in transmitter concentrations has now been clearly demonstrated. The increased availability of caged compounds and of the technologies required to exploit them provides neurobiologists with powerful tools for probing neuronal response properties and connectivity patterns.
Collapse
Affiliation(s)
- J M Nerbonne
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, Missouri 63110, USA.
| |
Collapse
|
18
|
Synthesis and Characterization of Photolabile Choline Precursors as Reversible Inhibitors of Cholinesterases: Release of Choline in the Microsecond Time Range. J Org Chem 1996. [DOI: 10.1021/jo951190c] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ling Peng
- Laboratoire de Chimie Bio-organique, URA 1386 CNRS−Faculté de Pharmacie, Université Louis Pasteur Strasbourg, BP 24, 67401 Illkirch Cedex, France
| | - Maurice Goeldner
- Laboratoire de Chimie Bio-organique, URA 1386 CNRS−Faculté de Pharmacie, Université Louis Pasteur Strasbourg, BP 24, 67401 Illkirch Cedex, France
| |
Collapse
|
19
|
Kinetics of prephosphorylation reactions and myosin light chain phosphorylation in smooth muscle. Flash photolysis studies with caged calcium and caged ATP. J Biol Chem 1995; 270:23966-74. [PMID: 7592592 DOI: 10.1074/jbc.270.41.23966] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The pre-myosin light chain (MLC20) phosphorylation components of the lag phase (td) of contractile activation were determined in permeabilized smooth muscles activated by photolytic release of ATP from caged ATP and/or Ca2+ from 4-(2-nitrophenyl)-EGTA (NP-EGTA). Calmodulin (CaM) shortened the td (470 ms at 0 added CaM) that followed Ca2+ release, but its effect (td = approximately 200 ms) saturated at 40 microM. Photolysis of caged ATP following preequilibration with identical [Ca4CaM] shortened td to 41 ms. The rate of phosphorylation was very fast (3.5 s-1 at 22 degrees C in the presence of 5 microM exogenous CaM) following photolysis of caged ATP, and, following Ca2+ release, phosphorylation was accelerated by CaM. Simultaneous photolysis of caged ATP and NP-EGTA was followed by a td of 194 ms at 5 microM CaM and a rate of MLC20 phosphorylation intermediate between these parameters following photolysis of, respectively, NP-EGTA and caged ATP. In the presence of the normal, total endogenous CaM content (37 +/- 4 microM) of protal vein smooth muscles td was 565 ms. Steady state maximum force at pCa 5.5 was increased by much lower (100 nM) exogenous [CaM] than was required (> 2.5 microM) to shorten the td. We estimate the endogenous CaM available under steady state conditions in vivo to be approximately 0.25 microM and probably less during a rapid Ca2+ transient. We conclude that the [CaM] dependence of the kinetics of MLC20 phosphorylation and force development (t1/2 and td) initiated by Ca2+ reflects the recruitment of a slowly diffusible component of total CaM. The relatively long duration of td (197 ms) at saturating [CaM] suggests the contribution to td of an additional component, possibly a prephosphorylation activation/isomerization of the Ca4CaM myosin light chain kinase complex (Török, K., and Trentham, D. R. (1994) Biochemistry 33, 12807-12820). The relatively short delay (108 ms in the presence of 40 microM CaM) following simultaneous photolysis of NP-EGTA and caged ATP suggests that preincubation with ATP (prior to photolysis of NP-EGTA) may inhibit the formation of a preactive Ca2CaM myosin light chain kinase complex.
Collapse
Affiliation(s)
- B Zimmermann
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville 22908, USA
| | | | | | | | | |
Collapse
|