1
|
Bhowmik R, Roy M. Recent advances on the development of NO-releasing molecules (NORMs) for biomedical applications. Eur J Med Chem 2024; 268:116217. [PMID: 38367491 DOI: 10.1016/j.ejmech.2024.116217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/19/2024]
Abstract
Nitric oxide (NO) is an important biological messenger as well as a signaling molecule that participates in a broad range of physiological events and therapeutic applications in biological systems. However, due to its very short half-life in physiological conditions, its therapeutic applications are restricted. Efforts have been made to develop an enormous number of NO-releasing molecules (NORMs) and motifs for NO delivery to the target tissues. These NORMs involve organic nitrate, nitrite, nitro compounds, transition metal nitrosyls, and several nanomaterials. The controlled release of NO from these NORMs to the specific site requires several external stimuli like light, sound, pH, heat, enzyme, etc. Herein, we have provided a comprehensive review of the biochemistry of nitric oxide, recent advancements in NO-releasing materials with the appropriate stimuli of NO release, and their biomedical applications in cancer and other disease control.
Collapse
Affiliation(s)
- Rintu Bhowmik
- Department of Chemistry, National Institute of Technology Manipur, Langol, 795004, Imphal West, Manipur, India
| | - Mithun Roy
- Department of Chemistry, National Institute of Technology Manipur, Langol, 795004, Imphal West, Manipur, India.
| |
Collapse
|
2
|
Inoue BKN, Paludetto LV, Monteiro NG, Batista FRDS, Kitagawa IL, da Silva RS, Antoniali C, Lisboa Filho PN, Okamoto R. Synergic Action of Systemic Risedronate and Local Rutherpy in Peri-implantar Repair of Ovariectomized Rats: Biomechanical and Molecular Analysis. Int J Mol Sci 2023; 24:16153. [PMID: 38003342 PMCID: PMC10671386 DOI: 10.3390/ijms242216153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/03/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Postmenopausal osteoporosis and poor dietary habits can lead to overweightness and obesity. Bisphosphonates are the first-line treatment for osteoporosis. However, some studies show that they may increase the risk of osteonecrosis of the jaw. Considering the antimicrobial, angiogenic and vasodilatory potential of nitric oxide, this study aims to evaluate the local activity of this substance during the placement of surface-treated implants. Seventy-two Wistar rats were divided into three groups: SHAM (SHAM surgery), OVX + HD (ovariectomy + cafeteria diet), and OVX + HD + RIS (ovariectomy + cafeteria diet + sodium risedronate treatment), which were further subdivided according to the surface treatment of the future implant: CONV (conventional), TE10, or TE100 (TERPY at 10 or 100 μM concentration); n = 8 per subgroup. The animals underwent surgery for implant installation in the proximal tibia metaphysis and were euthanized after 28 days. Data obtained from removal torque and RT-PCR (OPG, RANKL, ALP, IBSP and VEGF expression) were subjected to statistical analysis at 5% significance level. For biomechanical analysis, TE10 produced better results in the OVX + HD group (7.4 N/cm, SD = 0.6819). Molecular analysis showed: (1) significant increase in OPG gene expression in OVX groups with TE10; (2) decreased RANKL expression in OVX + HD + RIS compared to OVX + HD; (3) significantly increased expressions of IBSP and VEGF for OVX + HD + RIS TE10. At its lowest concentration, TERPY has the potential to improve peri-implant conditions.
Collapse
Affiliation(s)
- Bruna Kaori Namba Inoue
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| | - Laura Vidoto Paludetto
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| | - Naara Gabriela Monteiro
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| | - Fábio Roberto de Souza Batista
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| | - Igor Lebedenco Kitagawa
- Federal Institute of Education, Science and Technology of São Paulo (IFSP), Birigui 16201-407, SP, Brazil;
| | - Roberto Santana da Silva
- Department of Biomolecular Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo—USP, Ribeirão Preto 14040-403, SP, Brazil;
| | - Cristina Antoniali
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| | - Paulo Noronha Lisboa Filho
- Department of Physics and Meteorology, Bauru Sciences School, São Paulo State University Júlio de Mesquita Filho—UNESP, Bauru 17033-360, SP, Brazil;
| | - Roberta Okamoto
- Department of Basic Sciences, Araçatuba Dental School, São Paulo State University Júlio de Mesquita Filho—UNESP, Aracatuba 16015-050, SP, Brazil; (B.K.N.I.); (L.V.P.); (N.G.M.); (F.R.d.S.B.); (C.A.)
| |
Collapse
|
3
|
Vorobyev V, Budkina DS, Tarnovsky AN. Femtosecond Excited-State Dynamics and Nitric Oxide Photorelease in a Prototypical Ruthenium Nitrosyl Complex. J Phys Chem Lett 2020; 11:4639-4643. [PMID: 32397714 DOI: 10.1021/acs.jpclett.0c01105] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Excited-state relaxation of a prototypical ruthenium nitrosyl complex (pentachloronitrosylruthenate) in water is studied by means of ultrafast dispersed, broadband transient absorption spectroscopy. Excitation pulses (duration, 40-70 fs) utilized at seven different wavelengths in the range from 675 to 335 nm populated excited electronic states of different orbital nature. The second excited singlet state of πNO* nature relaxes into the lowest triplet 3πNO* state in 100 fs via the 1d-d intermediate (lowest excited singlet) state with ca. 80 fs lifetime. The 3πNO* lifetime is 3.2 ps, and all three states are inert toward NO release, which happens in less than 200 fs from higher excited states. The vibrational coherences observed are attributed to the Jahn-Teller effect in the 1πNO* state and nitric oxide loss and provide important insights into the nature of the reaction coordinate in the course of the ultrafast excited-state relaxation dynamics.
Collapse
Affiliation(s)
- Vasily Vorobyev
- Department of Chemistry and the Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Darya S Budkina
- Department of Chemistry and the Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Alexander N Tarnovsky
- Department of Chemistry and the Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| |
Collapse
|
4
|
Light-triggered release of photocaged therapeutics - Where are we now? J Control Release 2019; 298:154-176. [PMID: 30742854 DOI: 10.1016/j.jconrel.2019.02.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/04/2019] [Accepted: 02/06/2019] [Indexed: 01/02/2023]
Abstract
The current available therapeutics face several challenges such as the development of ideal drug delivery systems towards the goal of personalized treatments for patients benefit. The application of light as an exogenous activation mechanism has shown promising outcomes, owning to the spatiotemporal confinement of the treatment in the vicinity of the diseased tissue, which offers many intriguing possibilities. Engineering therapeutics with light responsive moieties have been explored to enhance the bioavailability, and drug efficacy either in vitro or in vivo. The tailor-made character turns the so-called photocaged compounds highly desirable to reduce the side effects of drugs and, therefore, have received wide research attention. Herein, we seek to highlight the potential of photocaged compounds to obtain a clear understanding of the mechanisms behind its use in therapeutic delivery. A deep overview on the progress achieved in the design, fabrication as well as current and possible future applications in therapeutics of photocaged compounds is provided, so that novel formulations for biomedical field can be designed.
Collapse
|
5
|
Kumar R, Yadav A, Ratnam A, Kumar S, Bala M, Sur D, Narang S, Singh UP, Mandal PK, Ghosh K. Organometallic Ruthenium Nitrosyl Obtained by C-H Bond Activation - Photoinduced Delivery of Nitric Oxide and NO-Mediated Antiproliferation Activity Studies. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700839] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Rajan Kumar
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Anjlika Yadav
- Department of Biotechnology; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Anand Ratnam
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Sushil Kumar
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Manju Bala
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Debpali Sur
- Department of Biotechnology; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Shikha Narang
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Udai P. Singh
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Prabhat K. Mandal
- Department of Biotechnology; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| | - Kaushik Ghosh
- Department of Chemistry; Indian Institute of Technology, Roorkee; 247667 Roorkee Uttarakhand India
| |
Collapse
|
6
|
Padamsey Z, Tong R, Emptage N. Glutamate is required for depression but not potentiation of long-term presynaptic function. eLife 2017; 6:29688. [PMID: 29140248 PMCID: PMC5714480 DOI: 10.7554/elife.29688] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/14/2017] [Indexed: 12/20/2022] Open
Abstract
Hebbian plasticity is thought to require glutamate signalling. We show this is not the case for hippocampal presynaptic long-term potentiation (LTPpre), which is expressed as an increase in transmitter release probability (Pr). We find that LTPpre can be induced by pairing pre- and postsynaptic spiking in the absence of glutamate signalling. LTPpre induction involves a non-canonical mechanism of retrograde nitric oxide signalling, which is triggered by Ca2+ influx from L-type voltage-gated Ca2+ channels, not postsynaptic NMDA receptors (NMDARs), and does not require glutamate release. When glutamate release occurs, it decreases Pr by activating presynaptic NMDARs, and promotes presynaptic long-term depression. Net changes in Pr, therefore, depend on two opposing factors: (1) Hebbian activity, which increases Pr, and (2) glutamate release, which decreases Pr. Accordingly, release failures during Hebbian activity promote LTPpre induction. Our findings reveal a novel framework of presynaptic plasticity that radically differs from traditional models of postsynaptic plasticity. Neurons communicate with one another at junctions called synapses. One neuron at the synapse releases a chemical substance called a neurotransmitter, which binds to and activates the other neuron. The release of neurotransmitter thus enables the electrical activity of one cell to influence the electrical activity of another. The efficiency of this communication can change over time, as is thought to occur during learning. If the neurons on both sides of a synapse are repeatedly active at the same time, the ability of the neurons to transmit electrical signals to each other increases. One way that communication between neurons can become more efficient is if the first neuron becomes more likely to release neurotransmitter. Most synapses in the brain release a neurotransmitter called glutamate, and most types of learning involve changes in the efficiency of communication at glutamatergic synapses. But glutamate release is unreliable. Active glutamatergic neurons fail to release glutamate about 80% of the time. If glutamate has a key role in learning, how does the brain learn efficiently when glutamate release is so unlikely? To find out, Padamsey et al. studied glutamatergic synapses in slices of tissue from mouse and rat brains. When both neurons at a synapse were repeatedly active at the same time, the first neuron would sometimes become more likely to release glutamate. But this only happened at synapses in which the first neuron usually failed to release glutamate in the first place. This suggests that communication failures help to drive change at synapses. When two neurons that are often active at the same time do not communicate efficiently, this failure triggers molecular changes that make future communication more reliable. Previous results have shown that synapses can change when glutamate release occurs. The current results show that they can also change when it does not. This means that the brain can continue to learn despite frequent communication failures between neurons. Many neurological disorders, including Alzheimer’s disease, show altered glutamate signalling at synapses. Padamsey et al. hope that a better understanding of this process will lead to new therapies for these disorders.
Collapse
Affiliation(s)
- Zahid Padamsey
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Rudi Tong
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nigel Emptage
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
7
|
Dunkel P, Petit M, Dhimane H, Blanchard-Desce M, Ogden D, Dalko PI. Quinoline-Derived Two-Photon-Sensitive Octupolar Probes. ChemistryOpen 2017; 6:660-667. [PMID: 29046861 PMCID: PMC5641908 DOI: 10.1002/open.201700097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Indexed: 01/05/2023] Open
Abstract
A systematic study on quinoline‐derived light sensitive probes, having third‐order rotational symmetry is presented. The electronically linked octupolar structures show considerably improved linear and nonlinear photophysical properties under one‐ and two‐photon irradiation conditions compared to the corresponding monomers. Photolysis of the three acetate derivatives shows strong structure dependency: whereas irradiation of the 6‐ and 7‐aminoquinoline derivatives resulted in fast intramolecular cyclization and only trace amounts of fragmentation products, the 8‐aminoquinoline derivative afforded clean and selective photolysis, with a sequential release of their acetate groups (δu[730]=0.67 GM).
Collapse
Affiliation(s)
- Petra Dunkel
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques Université Paris Descartes 45, rue des Saints-Pères 75270 Paris Cedex 06 France
| | - Morgane Petit
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques Université Paris Descartes 45, rue des Saints-Pères 75270 Paris Cedex 06 France
| | - Hamid Dhimane
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques Université Paris Descartes 45, rue des Saints-Pères 75270 Paris Cedex 06 France
| | - Mireille Blanchard-Desce
- Université de Bordeaux ISM (CNRS UMR5255) Bâtiment A12, 351, Cours de la Libération 33405 Talence Cedex France
| | - David Ogden
- Laboratoire de Physiologie Cérébrale Université Paris Descartes 45, rue des Saints-Pères 75270 Paris Cedex 06 France
| | - Peter I Dalko
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques Université Paris Descartes 45, rue des Saints-Pères 75270 Paris Cedex 06 France
| |
Collapse
|
8
|
Zhang Z, Wu J, Shang Z, Wang C, Cheng J, Qian X, Xiao Y, Xu Z, Yang Y. Photocalibrated NO Release from N-Nitrosated Napthalimides upon One-Photon or Two-Photon Irradiation. Anal Chem 2016; 88:7274-80. [DOI: 10.1021/acs.analchem.6b01603] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | - Chao Wang
- State
Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116024, China
| | | | | | - Yi Xiao
- State
Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning 116024, China
| | | | | |
Collapse
|
9
|
Nichols SP, Storm WL, Koh A, Schoenfisch MH. Local delivery of nitric oxide: targeted delivery of therapeutics to bone and connective tissues. Adv Drug Deliv Rev 2012; 64:1177-88. [PMID: 22433782 PMCID: PMC3383916 DOI: 10.1016/j.addr.2012.03.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 02/17/2012] [Accepted: 03/05/2012] [Indexed: 01/15/2023]
Abstract
Non-invasive treatment of injuries and disorders affecting bone and connective tissue remains a significant challenge facing the medical community. A treatment route that has recently been proposed is nitric oxide (NO) therapy. Nitric oxide plays several important roles in physiology with many conditions lacking adequate levels of NO. As NO is a radical, localized delivery via NO donors is essential to promoting biological activity. Herein, we review current literature related to therapeutic NO delivery in the treatment of bone, skin and tendon repair.
Collapse
Affiliation(s)
- Scott P Nichols
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | | | | | | |
Collapse
|
10
|
|
11
|
Lahiri GK, Kaim W. Electronic structure alternatives in nitrosylruthenium complexes. Dalton Trans 2010; 39:4471-8. [DOI: 10.1039/c002173c] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
12
|
Rose MJ, Mascharak PK. Photosensitization of Ruthenium Nitrosyls to Red Light with an Isoelectronic Series of Heavy-Atom Chromophores: Experimental and Density Functional Theory Studies on the Effects of O-, S- and Se-Substituted Coordinated Dyes. Inorg Chem 2009; 48:6904-17. [DOI: 10.1021/ic900899j] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Michael J. Rose
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
| | - Pradip K. Mascharak
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
| |
Collapse
|
13
|
Rose MJ, Mascharak PK. Photoactive Ruthenium Nitrosyls: Effects of Light and Potential Application as NO Donors. Coord Chem Rev 2008; 252:2093-2114. [PMID: 21052477 PMCID: PMC2967751 DOI: 10.1016/j.ccr.2007.11.011] [Citation(s) in RCA: 251] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Michael J. Rose
- Department of Chemistry & Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Pradip K. Mascharak
- Department of Chemistry & Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| |
Collapse
|
14
|
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
|
15
|
Ford PC. Polychromophoric metal complexes for generating the bioregulatory agent nitric oxide by single- and two-photon excitation. Acc Chem Res 2008; 41:190-200. [PMID: 18181579 DOI: 10.1021/ar700128y] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to deliver a bioactive agent to a physiological location, it is important to be able to regulate precisely the location and the dosage. Such exquisite control can easily be envisioned for a photochemical drug that is active toward release of the desired bioactive agent upon irradiation of a specific tissue site. These materials should be thermally stable but reactive under excitation at visible (vis) or near-infrared (NIR) wavelengths where tissue transmission is optimal. Two photon excitation (TPE) is of special interest, since the use of focused laser pulses to activate release could provide 3D spatial control in therapeutic applications. This Account describes the preparation and photochemistry of a series of transition metal complexes designed to release the simple bioregulatory compound nitric oxide upon vis or NIR excitation. In order to enhance the light gathering capability of such compounds, we have attached chromophores with high single- or two-photon absorption cross sections to several photochemical NO precursors. For example, the iron nitrosyl clusters Fe2(mu-SR)2(NO)4 (Roussin's red esters) have been prepared with various chromophores as pendant groups, an example being the protoporphyrin XI derivative illustrated here. Direct excitation into the vis absorbing Q bands of the porphyrin leads to enhanced rates of NO generation from the Fe/S/NO cluster owing to the larger rate of light absorption by that antenna. Furthermore, femtosecond pulsed laser NIR excitation of the same compound at 810 nm (a spectral region where no absorption bands are apparent) leads to weak emission at approximately 630 nm and generation of NO, both effects providing evidence of a TPE mechanism. Roussin's red esters with other chromophores described here are even more effective for TPE-stimulated NO release. Another photochemical NO precursor discussed is the Cr(III) complex trans-Cr(L)(ONO)2(+) where L is a cyclic tetraamine such as cyclam. When L includes a chromophore tethered to the ligand backbone, excitation of that functionality results in energy transfer to the spin-forbidden ligand field double states and light-stimulated release of NO. We are working to develop systems where L is attached to a semiconductor nanoparticle as the antenna. In this context, we have shown that electrostatic assemblies are formed between the anionic surface of water-soluble CdSe/ZnS core/shell quantum dots (QDs) and Cr(L)(ONO)2(+) cations via an ion-pairing mechanism. Photoexcition of such modified QDs leads to markedly enhanced NO generation and suggests promising applications of such nanomaterials as photochemical drugs.
Collapse
Affiliation(s)
- Peter C. Ford
- Department of Chemistry and Biochemistry, University of California, Santa Barbara Santa Barbara, California 93106-9510
| |
Collapse
|
16
|
Rose MJ, Patra AK, Alcid EA, Olmstead MM, Mascharak PK. Ruthenium Nitrosyls Derived from Polypyridine Ligands with Carboxamide or Imine Nitrogen Donor(s): Isoelectronic Complexes with Different NO Photolability. Inorg Chem 2007; 46:2328-38. [PMID: 17315866 DOI: 10.1021/ic0620945] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As part of our search for photoactive ruthenium nitrosyls, a set of {RuNO}6 nitrosyls has been synthesized and structurally characterized. In this set, the first nitrosyl [(SBPy3)Ru(NO)](BF4)3 (1) is derived from a polypyridine Schiff base ligand SBPy3, while the remaining three nitrosyls are derived from analogous polypyridine ligands containing either one ([(PaPy3)Ru(NO)](BF4)2 (2)) or two ([(Py3P)Ru(NO)]BF4 (3) and [(Py3P)Ru(NO)(Cl)] (4)) carboxamide group(s). The coordination structures of 1 and 2 are very similar except that in 2, a carboxamido nitrogen is coordinated to the ruthenium center in place of an imine nitrogen in case of 1. In 3 and 4, the ruthenium center is coordinated to two carboxamido nitrogens in the equatorial plane and the bound NO is trans to a pyridine nitrogen (in 3) and chloride (in 4), respectively. Complexes 1-3 contain N6 donor set, and the NO stretching frequencies (nuNO) correlate well with the N-O bond distances. All four diamagnetic {RuNO}(6) nitrosyls are photoactive and release NO rapidly upon illumination with low-intensity (5-10 mW) UV light. Interestingly, photolysis of 1 generates the diamagnetic Ru(II) photoproduct [(SBPy3)Ru(MeCN)](2+) while 2-4 afford paramagnetic Ru(III) species in MeCN solution. The quantum yield values of NO release under UV illumination (lambda(max) = 302 nm) lie in the range 0.06-0.17. Complexes 3 and 4 also exhibit considerable photoactivity under visible light. The efficiency of NO release increases in the order 2 < 3 < 4, indicating that photorelease of NO is facilitated by (a) the increase in the number of coordinated carboxamido nitrogen(s) and (b) the presence of negatively charged ligands (like chloride) trans to the bound NO.
Collapse
Affiliation(s)
- Michael J Rose
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
| | | | | | | | | |
Collapse
|
17
|
A novel porphyrin–polypyridyl ruthenium(II) hybrid. Synthesis, characterization and photoinduced DNA cleavage activity. TRANSIT METAL CHEM 2006. [DOI: 10.1007/s11243-006-0106-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
18
|
Sarkar S, Sarkar B, Chanda N, Kar S, Mobin SM, Fiedler J, Kaim W, Lahiri GK. Complex series [Ru(tpy)(dpk)(X)]n+ (tpy = 2,2':6',2''-terpyridine; dpk = 2,2'-dipyridyl ketone; X = Cl-, CH3CN, NO2(-), NO+, NO*, NO-): substitution and electron transfer, structure, and spectroscopy. Inorg Chem 2006; 44:6092-9. [PMID: 16097830 DOI: 10.1021/ic050533e] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The complex framework [Ru(tpy)(dpk)]2+ has been used to study the generation and reactivity of the nitrosyl complex [Ru(tpy)(dpk)(NO)]3+ ([4]3+). Stepwise conversion of the chloro complex [Ru(tpy)(dpk)(Cl)]+ ([1]+) via [Ru(tpy)(dpk)(CH3CN)]2+ ([2]2+) and the nitro compound [Ru(tpy)(dpk)(NO2)]+ ([3]+) yielded [4]3+; all four complexes were structurally characterized as perchlorates. Electrochemical oxidation and reduction was investigated as a function of the monodentate ligand as was the IR and UV-vis spectroscopic response (absorption/emission). The kinetics of the conversion [4]3+/[3]+ in aqueous environment were also studied. Two-step reduction of [4]3+ was monitored via EPR, UV-vis, and IR (nu(NO), nu(CO)) spectroelectrochemistry to confirm the {RuNO}7 configuration of [4]2+ and to exhibit a relatively intense band at 505 nm for [4]+, attributed to a ligand-to-ligand transition originating from bound NO-.
Collapse
Affiliation(s)
- Sounak Sarkar
- Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai-400076, India
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Tate EW. Chemical intervention in signalling networks: recent advances and applications. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/sita.200500075] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
20
|
|
21
|
Ferezin CZ, Oliveira FS, da Silva RS, Simioni AR, Tedesco AC, Bendhack LM. The complex trans-[RuCl([15]aneN4NO]2+ induces rat aorta relaxation by ultraviolet light irradiation. Nitric Oxide 2005; 13:170-5. [PMID: 16054406 DOI: 10.1016/j.niox.2005.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 06/06/2005] [Accepted: 06/07/2005] [Indexed: 02/07/2023]
Abstract
The aim of the present study was to investigate the possible endogenous storage of photosensitive nitric oxide, and also to examine the relaxant effect of NO released from the compound by UV light irradiation. Aorta was isolated from rats and the endothelium was mechanically removed. Denuded aortic rings pre-contracted with prostaglandin F(2alpha) responded with relaxation to UV light irradiation. The first stimulation produced the greatest response that decreased until complete disappearance. After this, the addition of the compound in the absence of light did not produce any response. However, in the presence of UV light irradiation, the complex trans-[RuCl([15]aneN4)NO]2+ induced 100% relaxation. After incubation with the nitric oxide scavenger, oxyhaemoglobin, this relaxation was completely abolished. In PGF2(2alpha)-pre-contracted aortas, the time to reach maximum relaxation was only 50s. Taken together, these results suggest that preformed endogenous nitric oxide stores exist in the denuded rat aorta, and that they are sensitive to UV light. The photo-induction of the complex trans-[RuCl([15]aneN4NO]2+ induces complete aorta relaxation, which is due to release of nitric oxide in the extracellular medium.
Collapse
Affiliation(s)
- Camila Z Ferezin
- Depto. de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Ribeirão Preto, SP, Brazil
| | | | | | | | | | | |
Collapse
|
22
|
Toma HE, Alexiou AD, Formiga ALB, Nakamura M, Dovidauskas S, Eberlin MN, Tomazela DM. A nitric oxide releaser based on the μ-oxo-hexaacetate-bis(4-methylpyridine)triruthenium nitrosyl complex. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
23
|
Karidi K, Garoufis A, Tsipis A, Hadjiliadis N, den Dulk H, Reedijk J. Synthesis, characterization, in vitro antitumor activity, DNA-binding properties and electronic structure (DFT) of the new complex cis-(Cl,Cl)[RuIICl2(NO+)(terpy)]Cl. Dalton Trans 2005:1176-87. [PMID: 15782252 DOI: 10.1039/b418838a] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The complex cis-(Cl,Cl)-[RuCl2(terpy)(NO)]Cl (1) has been synthesized by the reaction of [RuCl3(H2O)2(NO)] with terpyridine (terpy) and characterized by various spectroscopic, analytical techniques and using electronic structure calculation (DFT) methods. The cytotoxic activity and the DNA-binding properties of have also been studied using biochemical techniques. The results establish unequivocally that corresponds to a so-called [RuNO]6 species, which readily releases the nitrosyl ligand upon irradiation with a mercury lamp in acetonitrile solution. DFT calculations provided a satisfactory description of structural, bonding, electronic and related properties of the new compound and throw light on the mechanism of the photo-induced NO release. Screening on A2780 (human ovarian carcinoma) cell lines showed significant cytotoxicity with an IC50 value of 0.49 microM. 31P and 23Na NMR spectroscopy along with electrophoretic mobility studies illustrated that complex primarily binds by coordination to DNA without any pi-interaction between the planar terpy ligand and the DNA bases, while weak electrostatic interactions could not be excluded. Studies on the inhibition of the restriction enzymes DraI and SmaI revealed that prefers the guanine and cytosine bases of DNA.
Collapse
Affiliation(s)
- Konstantina Karidi
- Laboratory of Inorganic and General Chemistry, Department of Chemistry, University of Ioannina, Greece
| | | | | | | | | | | |
Collapse
|
24
|
Weichsel A, Maes EM, Andersen JF, Valenzuela JG, Shokhireva TK, Walker FA, Montfort WR. Heme-assisted S-nitrosation of a proximal thiolate in a nitric oxide transport protein. Proc Natl Acad Sci U S A 2005; 102:594-9. [PMID: 15637157 PMCID: PMC545542 DOI: 10.1073/pnas.0406549102] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Accepted: 11/30/2004] [Indexed: 11/18/2022] Open
Abstract
Certain bloodsucking insects deliver nitric oxide (NO) while feeding, to induce vasodilation and inhibit blood coagulation. We have expressed, characterized, and determined the crystal structure of the Cimex lectularius (bedbug) nitrophorin, the protein responsible for NO storage and delivery, to understand how the insect successfully handles this reactive molecule. Surprisingly, NO binds not only to the ferric nitrophorin heme, but it can also be stored as an S-nitroso (SNO) conjugate of the proximal heme cysteine (Cys-60) when present at higher concentrations. EPR- and UV-visible spectroscopies, and a crystallographic structure determination to 1.75-A resolution, reveal SNO formation to proceed with reduction of the heme iron, yielding an Fe-NO complex. Stopped-flow kinetic measurements indicate that an ordered reaction mechanism takes place: initial NO binding occurs at the ferric heme and is followed by heme reduction, Cys-60 release from the heme iron, and SNO formation. Release of NO occurs through a reversal of these steps. These data provide, to our knowledge, the first view of reversible metal-assisted SNO formation in a protein and suggest a mechanism for its role in NO release from ferrous heme. This mechanism and Cimex nitrophorin structure are completely unlike those of the nitrophorins from Rhodnius prolixus, where NO protection is provided by a large conformational change that buries the heme nitrosyl complex, highlighting the remarkable evolution of proteins that assist insects in bloodfeeding.
Collapse
Affiliation(s)
- Andrzej Weichsel
- Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Chanda N, Mobin SM, Puranik VG, Datta A, Niemeyer M, Lahiri GK. Stepwise synthesis of [Ru(trpy)(L)(X)](n+) (trpy = 2,2':6',2' '-terpyridine; L = 2,2'-dipyridylamine; X = Cl-, H2O, NO2-, NO+, O2-). Crystal structure, spectral, electron-transfer, and photophysical aspects. Inorg Chem 2004; 43:1056-64. [PMID: 14753828 DOI: 10.1021/ic034902n] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ruthenium-terpyridine complexes incorporating a 2,2'-dipyridylamine ancillary ligand [Ru(II)(trpy)(L)(X)](ClO(4))(n) [trpy = 2,2':6',2' '-terpyridine; L = 2,2'-dipyridylamine; and X = Cl(-), n = 1 (1); X = H(2)O, n = 2 (2); X = NO(2)(-), n = 1 (3); X = NO(+), n = 3 (4)] were synthesized in a stepwise manner starting from Ru(III)(trpy)(Cl)(3). The single-crystal X-ray structures of all of the four members (1-4) were determined. The Ru(III)/Ru(II) couple of 1 and 3 appeared at 0.64 and 0.88 V versus the saturated calomel electrode in acetonitrile. The aqua complex 2 exhibited a metal-based couple at 0.48 V in water, and the potential increased linearly with the decrease in pH. The electron-proton content of the redox process over the pH range of 6.8-1.0 was calculated to be a 2e(-)/1H(+) process. However, the chemical oxidation of 2 by an aq Ce(IV) solution in 1 N H(2)SO(4) led to the direct formation of corresponding oxo species [Ru(IV)(trpy)(L)(O)](2+) via the concerted 2e(-)/2H(+) oxidation process. The two successive reductions of the coordinated nitrosyl function of 4 appeared at +0.34 and -0.34 V corresponding to Ru(II)-NO(+) --> Ru(II)-NO* and Ru(II)-NO* --> Ru(II)-NO(-), respectively. The one-electron-reduced Ru(II)-NO* species exhibited a free-radical electron paramagnetic resonance signal at g = 1.990 with nitrogen hyperfine structures at 77 K. The NO stretching frequency of 4 (1945 cm(-1)) was shifted to 1830 cm(-1) in the case of [Ru(II)(trpy)(L)(NO*)](2+). In aqueous solution, the nitrosyl complex 4 slowly transformed to the nitro derivative 3 with the pseudo-first-order rate constant of k(298)/s(-1) = 1.7 x 10(-4). The chloro complex 1 exhibited a dual luminescence at 650 and 715 nm with excited-state lifetimes of 6 and 1 micros, respectively.
Collapse
Affiliation(s)
- Nripen Chanda
- Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India
| | | | | | | | | | | |
Collapse
|
26
|
Shepherd RE, Slocik JM, Stringfield TW, Somayajula KV, Amoscato AA. Electrospray mass spectrometry of cis-[Ru(NO)Cl(bpy)2]2+ (bpy=2,2′-bipyridine): fragmentation from desolvated {[Ru(NO)Cl(bpy)2]2+, Cl−}+ ion pairs by electron transfer and internal Lewis base pathways. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2003.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
27
|
Different isomers of [RuII(NO+)(hedta)(H2O)] prepared from Ru(NO)Cl3 via chelation by hedta3− than by NO2− addition to [Ru(H2O)(hedta)]−. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(02)01199-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
28
|
Tfouni E, Krieger M, McGarvey BR, Franco DW. Structure, chemical and photochemical reactivity and biological activity of some ruthenium amine nitrosyl complexes. Coord Chem Rev 2003. [DOI: 10.1016/s0010-8545(02)00177-7] [Citation(s) in RCA: 217] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
29
|
Ruane PH, Bushan KM, Pavlos CM, D'Sa RA, Toscano JP. Controlled photochemical release of nitric oxide from O2-benzyl-substituted diazeniumdiolates. J Am Chem Soc 2002; 124:9806-11. [PMID: 12175240 DOI: 10.1021/ja026900s] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An investigation of potential photosensitive protecting groups for diazeniumdiolates (R2N-N(O)=NO-) has been initiated, and here the effect of meta electron-donating groups on the photochemistry of O2-benzyl-substituted diazeniumdiolates (R2N-N(O)=NOCH2Ar) is reported. Photolysis of the parent benzyl derivative (Ar = Ph) results almost exclusively in undesired photochemistry-the formation of nitrosamine and an oxynitrene intermediate with very little, if any, photorelease of the diazeniumdiolate. We have been able to use meta substitution to tune the photochemistry of these benzylic systems. The desired diazeniumdiolate photorelease has been shown to become more substantial with stronger pi-donating meta substituents. This effect has been verified by direct observation of the photoreleased diazeniumdiolate with 1H NMR spectroscopy and by NO quantification measurements conducted in high- and low-pH solutions. In addition, the observed rates of NO release are consistent with that expected for normal thermal decomposition of the diazeniumdiolate in aqueous solutions and also show the same pH dependence.
Collapse
Affiliation(s)
- Patrick H Ruane
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
| | | | | | | | | |
Collapse
|
30
|
Wanat A, Wolak M, Orzeł Ł, Brindell M, van Eldik R, Stochel G. Laser flash photolysis as tool in the elucidation of the nitric oxide binding mechanism to metallobiomolecules. Coord Chem Rev 2002. [DOI: 10.1016/s0010-8545(02)00091-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
31
|
Pelliccioli AP, Wirz J. Photoremovable protecting groups: reaction mechanisms and applications. Photochem Photobiol Sci 2002; 1:441-58. [PMID: 12659154 DOI: 10.1039/b200777k] [Citation(s) in RCA: 511] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photolabile protecting groups enable biochemists to control the release of bioactive compounds in living tissue. 'Caged compounds' (photoactivatable bioagents) have become an important tool to study the events that follow chemical signalling in, e.g., cell biology and the neurosciences. The possibilities are by no means exhausted. Progress will depend on the development of photoremovable protecting groups that satisfy the diverse requirements of new applications--a challenging task for photochemists.
Collapse
Affiliation(s)
- Anna Paola Pelliccioli
- Institut für Physikalische Chemie, Universität Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | | |
Collapse
|
32
|
Wang PG, Xian M, Tang X, Wu X, Wen Z, Cai T, Janczuk AJ. Nitric oxide donors: chemical activities and biological applications. Chem Rev 2002; 102:1091-134. [PMID: 11942788 DOI: 10.1021/cr000040l] [Citation(s) in RCA: 972] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Peng George Wang
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
| | | | | | | | | | | | | |
Collapse
|
33
|
Slocik JM, Somayajula KV, Shepherd RE. Electrospray mass spectrometry of trans-[Ru(NO)Cl(dpaH)2]2+ (dpaH=2,2′-dipyridylamine) and ‘caged NO’, [RuCl3(NO)(H2O)2]: loss of HCl and NO from positive ions versus NO and Cl from negative ions. Inorganica Chim Acta 2001. [DOI: 10.1016/s0020-1693(01)00487-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
34
|
Slocik JM, Ward MS, Shepherd RE. Synthesis and characterization of meso-[Ru(NO)Cl(dioxocyclam)] and the 1H NMR comparison with [MII(dioxocyclam)] complexes (MII=NiII and PdII) (dioxocyclam=1,4,8,11-tetraazacyclotetradecane-5,7-dione). Inorganica Chim Acta 2001. [DOI: 10.1016/s0020-1693(01)00427-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
35
|
Coordination of Ru(NO)Cl3 to the tripeptides glyglygly and glyglyhis: N-terminal amine–amide and C-terminal imidazole–amide functionalities in bidentate chelation. Inorganica Chim Acta 2000. [DOI: 10.1016/s0020-1693(00)00309-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
36
|
Wolak M, Stochel G, Hamza M, van Eldik R. Aquacobalamin (vitamin B12a) does not bind NO in aqueous solution. Nitrite impurities account for observed reaction. Inorg Chem 2000; 39:2018-9. [PMID: 12526506 DOI: 10.1021/ic991266d] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M Wolak
- Institute for Inorganic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany
| | | | | | | |
Collapse
|
37
|
Keelan J, Vergun O, Duchen MR. Excitotoxic mitochondrial depolarisation requires both calcium and nitric oxide in rat hippocampal neurons. J Physiol 1999; 520 Pt 3:797-813. [PMID: 10545145 PMCID: PMC2269623 DOI: 10.1111/j.1469-7793.1999.00797.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
1. Glutamate neurotoxicity has been attributed to cellular Ca2+ overload. As mitochondrial depolarisation may represent a pivotal step in the progression to cell death, we have used digital imaging techniques to examine the relationship between cytosolic Ca2+ concentration ([Ca2+]c) and mitochondrial potential (DeltaPsim) during glutamate toxicity, and to define the mechanisms underlying mitochondrial dysfunction. 2. In cells of > 11 days in vitro (DIV), exposure to 50 mM potassium or 100 microM glutamate had different consequences for DeltaPsim. KCl caused a small transient loss of DeltaPsim but in response to glutamate there was a profound loss of DeltaPsim. In cells of 7-10 DIV, glutamate caused only a modest and reversible drop in DeltaPsim. 3. Using fura-2 to measure [Ca2+]c, responses to KCl and glutamate did not appear significantly different. However, use of the low affinity indicator fura-2FF revealed a difference in the [Ca2+]c responses to KCl and glutamate, which clearly correlated with the loss of DeltaPsim. Neurons exhibiting a profound mitochondrial depolarisation also showed a large secondary increase in the fura-2FF ratio. 4. The glutamate-induced loss of DeltaPsim was dependent on Ca2+ influx. However, inhibition of nitric oxide synthase (NOS) by L-NAME significantly attenuated the loss of DeltaPsim. Furthermore, photolysis of caged NO at levels that had no effect alone promoted a profound mitochondrial depolarisation when combined with high [Ca2+]c, either in response to KCl or to glutamate in cultures at 7-10 DIV. 5. In cells that showed only modest mitochondrial responses to glutamate, induction of a mitochondrial depolarisation by the addition of NO was followed by a secondary rise in [Ca2+]c. These data suggest that [Ca2+]c and nitric oxide act synergistically to cause mitochondrial dysfunction and impaired [Ca2+]c homeostasis during glutamate toxicity.
Collapse
Affiliation(s)
- J Keelan
- Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK.
| | | | | |
Collapse
|
38
|
Abstract
1. Nitric oxide (NO) has been shown to modulate neuropeptide secretion from the posterior pituitary. Here we show that NO activates large-conductance Ca2+-activated K+ (BK) channels in posterior pituitary nerve terminals. 2. NO, generated either by the photolysis of caged-NO or with chemical donors, irreversibly enhanced the component of whole-terminal K+ current due to BK channels and increased the activity of BK channels in excised patches. NO also inhibited the transient A-current. The time courses of these effects on K+ current were very different; activation of BK channels developed slowly over several minutes whereas inhibition of A-current immediately followed NO uncaging. 3. Activation of BK channels by NO occurred in the presence of guanylyl cyclase inhibitors and after removal of ATP or GTP from the pipette solution, suggesting a cGMP-independent signalling pathway. 4. The sulfhydryl alkylating agent N-ethyl maleimide (NEM) increased BK channel activity. Pretreatment with NEM occluded NO activation. 5. NO activation of BK channels occurred independently of voltage and cytoplasmic Ca2+ concentration. In addition, NO removed the strict Ca2+ requirement for channel activation, rendering channels highly active even at nanomolar Ca2+ levels. 6. These results suggest that NO, or a reactive nitrogen byproduct, chemically modifies nerve terminal BK channels or a closely associated protein and thereby produces an increase in channel activity. Such activation is likely to inhibit impulse activity in posterior pituitary nerve terminals and this may explain the inhibitory action of NO on secretion.
Collapse
Affiliation(s)
- G P Ahern
- Department of Physiology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | | |
Collapse
|
39
|
Chen Y, Lin FT, Shepherd RE. 15N NMR and Electrochemical Studies of [Ru(II)(hedta)](-) Complexes of NO, NO(+), NO(2)(-), and NO(-). Inorg Chem 1999; 38:973-983. [PMID: 11670870 DOI: 10.1021/ic980868e] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Ru(II)(hedta)L](n)()(-) complexes (hedta(3)(-) = N-(hydroxyethyl)ethylenediaminetriacetate; L = NO(+), n = 0; L = NO, n = 1; L = NO(-), n = 2) have been prepared by the displacement of H(2)O/D(2)O via NO(g) or NO(2)(-). This is the first reported entire set of NO(+), NO, and NO(-) as ligands for the same metal center in a constant oxidation state and with a constant ligand environment (here Ru(II) and the amino carboxylate hedta(3)(-)). From the NO stretching frequencies of isolated salts, the net influence of back-donation by Ru(II) and its sigma-withdrawal was observed to be that the bond order for the NO(+) complex is virtually the same (ca. 2.46) as that for the NO complex (ca. 2.48). The back-donation to NO(-) is also small, as is that to NO, but orbital mixing of NO(-) and Ru(II) is sufficiently important to induce a singlet NO(-) complex. Values for the nu(NO) in cm(-)(1) for the (14)N- and (15)N-labeled complexes, respectively, are as follows: NO(+), 1846, 1827; NO, 1858, 1842; NO(-), 1383, 1370. Combined results of (15)N, (13)C, and (1)H NMR spectra of the complexes in D(2)O show that [Ru(II)(hedta)((15)NO(+))] is a single cis-equatorial isomer with its (15)NO(+) resonance at 249.6 ppm vs [(15)N]formamide. The two-electron-reduced [Ru(II)(hedta)((15)NO(-))](2)(-) complex exists as trans- and cis-equatorial isomers having (15)NO(-) resonances at 609.4 and 607.4 ppm. The (15)N resonances appear at 260.0 ppm for the (15)NO(+) ligand and at 348.8 ppm for the bound (15)NO(2)(-) ligand in the [Ru(II)(hedta)((15)NO(2)(-))((15)NO(+))(D(2)O)] complex. Differential pulse voltammetric waves for the [Ru(II)(hedta)L](n)()(-) series occur at -0.37 V for the Ru(II)(NO(-))/Ru(II)(NO) couple, at -0.10 V for the Ru(II)(NO)/Ru(II)(NO(+)) couple, and at +0.98 V for the Ru(II)(NO(+))/Ru(III)(NO(+)) couple. The coordinated nitrosyl ion/nitro equilibrium (L')Ru(II)(NO(+)) + 2OH(-) right harpoon over left harpoon (L')Ru(II)(NO(2)(-)) + H(2)O (K(NO)()2()-) was observed for L' = hedta(3)(-), as for previous examples with L' = violurate, polypyridyl ligands, and (CN(-))(5) and (NH(3))(5) ligand sets. K(NO)()2()- = 1.44 x 10(13) for L' = hedta(3)(-). log(K(NO)()2()-) is linearly related through the ion-pairing equilibrium constant expression to -z(1)z(2), the charge product of the reacting ions (here the (L')Ru(NO(+)) complex and OH(-)) from -4 through +3, excluding the (NH(3))(m)() ammine series with m = 4 and 5. The opposite behavior of the ammines is attributed to strong solvent H-bonding that changes for reactant and product in the nitrosyl/nitro equilibrium. The pK(a) of coordinated nitrous acid in [Ru(II)(hedta)(HONO)](-) is calculated to be -0.80, a 3.85 log unit enhancement over free HONO due to the Ru(II) charge. An MO explanation is presented to interrelate the {Fe(III)-(NO(-) triplet)} complexes, the {Ru(II)-(NO(-) singlet)} type observed for [Ru(II)(hedta)((15)NO(-))](2)(-), and the NO(+) complexes of other strong-field metals. When both d(z)()()2 and d(x)()()2(-)(y)()()2 metal orbitals reside below the NO pi pair, the electronic repulsions favor a bent NO(-) triplet ligand. If both metal orbitals reside above the NO pi pair, the orbital mixing and back-donation induce a coordinated NO(-) singlet ligand, and if the NO pi pair reside between the two sigma-based d orbitals, an NO(+) ligand and reduced metal center obtain.
Collapse
Affiliation(s)
- Ya Chen
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | | | | |
Collapse
|
40
|
Murphy KP, Bliss TV. Photolytically released nitric oxide produces a delayed but persistent suppression of LTP in area CA1 of the rat hippocampal slice. J Physiol 1999; 515 ( Pt 2):453-62. [PMID: 10050012 PMCID: PMC2269165 DOI: 10.1111/j.1469-7793.1999.453ac.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
1. We have used flash photolysis of a caged form of nitric oxide (NO), potassium pentachloronitrosylruthenate (K2Ru(NO)Cl5), to apply known concentrations of NO, with a high degree of temporal resolution, to hippocampal slices prepared from juvenile male rats maintained in an interface recording chamber. 2. Photolytically released NO (1-4.5 microM) from bath applied caged NO reduced the magnitude of long-term potentiation (LTP) in a concentration-dependent manner. This effect was abolished in the presence of the NO scavenger haemoglobin. NO had no effect on pre-established LTP. 3. Exposure to photolytically released NO had no effect on normal fast synaptic transmission, but did result in depression of N-methyl-D-aspartate (NMDA) receptor-mediated transmission recorded using extracellular electrodes. The onset of NO-induced depression was relatively slow, taking >40 s to manifest itself, and several minutes to achieve maximum depression (t approximately 70 s). NO-induced depression persisted for more than 2 h after photolysis. The time courses of the action of NO on NMDA receptor-mediated responses and its action on the induction of LTP were similar. 4. These results suggest that released NO may play a role in determining the subsequent threshold for the induction of LTP at Schaffer-commissural synapses through a reduction in the efficacy of NMDA receptor function when repeated conditioning trains are used.
Collapse
Affiliation(s)
- K P Murphy
- Division of Neurophysiology, National Institute for Medical Research, The Ridgeway, Mill Hill, London,
| | | |
Collapse
|
41
|
Carter TD, Bettache N, Ogden D. Potency and kinetics of nitric oxide-mediated vascular smooth muscle relaxation determined with flash photolysis of ruthenium nitrosyl chlorides. Br J Pharmacol 1997; 122:971-3. [PMID: 9401757 PMCID: PMC1565063 DOI: 10.1038/sj.bjp.0701549] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Flash photolysis of thermally stable, photolabile 'caged' precursors permits rapid and precise changes of ligand concentration at their site of action. This approach was used to determine the concentration-dependence and time course of NO-mediated relaxation of aortic smooth muscle, by use of two photolabile NO donors, trichloronitrosylruthenium (Ru(NO)Cl3) and dipotassium pentachloronitrosylruthenate (K2Ru(NO)Cl5). At concentrations up to 500 microM, both compounds were non-toxic before photolysis, and produced non-toxic by-products on photolysis. Photolytic release of NO produced relaxations of intact and endothelium-denuded aortic rings precontracted with noradrenaline (0.1-0.5 microM), with an EC50 for NO-mediated relaxations of 10.5 nM and 13 nM, respectively. NO-mediated relaxations were reversibly blocked by 1 microM oxyhaemoglobin. The time course of NO-mediated relaxation comprised a delay of 3-7 s, followed by a sigmoidal decline in tension with peak rates that were strongly dependent on NO concentration.
Collapse
Affiliation(s)
- T D Carter
- National Institute for Medical Research, London
| | | | | |
Collapse
|