Katrina M Miranda
Associate Professor, BIO5 Institute
Associate Professor, Chemistry and Biochemistry-Sci
Primary Department
(520) 626-3655
Work Summary
We seek to produce new drugs that harness molecules produced during the natural immune response in order to treat cancer and pain. Such compounds may also provide new treatments for heart failure and alcoholism.
Research Interest
Katrina Miranda, PhD, claims nitric oxide (NO), which is synthesized in the body via enzymatic oxidation of L-arginine, is critical to numerous physiological functions, but also can contribute to the severity of diseases such as cancer or pathophysiological conditions such as stroke. This diversity in the responses to NO biosynthesis is a reflection of the diverse chemistry of NO. For instance, NO can alter the function of enzymes by binding to metal centers. This type of interaction could result in outcomes as disparate as control of blood pressure or death of an invading bacterium. NO can also be readily converted to higher nitrogen oxides such as N2O3 or ONOOH, which have very different chemical and biological properties. The ultimate result will depend upon numerous factors, particularly the location and concentration of NO produced. Therefore, site-specific modulation of NO concentration offers intriguing therapeutic possibilities for an ever expanding list of diseases, including cancer, heart failure and stroke. As a whole, Dr. Miranda is interested in elucidating the fundamental molecular redox chemistry of NO and in developing compounds to deliver or scavenge NO and other nitrogen oxides. These projects are designed to answer questions of potential medical importance through a multi-disciplinary approach, including analytical, synthetic, inorganic and biochemical techniques.The project categories include five major disciplines. First, she will work on the development and utilization of analytical techniques for detection and measurement of NO and other nitrogen oxides as well as the resultant chemistry of these species. Second, she will synthesize potential donors or scavengers of NO and other nitrogen oxides. Third, it’s necessary to describe chemical characterization of these compounds (spectroscopic features, kinetics, mechanisms and profiles of nitrogen oxide release, etc.). Fourth, Dr. Miranda will try to describe the biological characterization of these compounds (assay of effects on biological compounds, mechanisms and pathways, in vitro determination of potential for therapeutic utility, etc.). Fifth, she will identify of potential targets, such as enzymes, for treatment of disease through exposure to nitrogen oxide donors. Keywords: cancer treatment, pain treatment

Publications

Boitano, S., Omsland, A., Miranda, K. M., Friedman, R. L., & Boitano, S. A. (2008). Bordetella bronchiseptica responses to physiological reactive nitrogen and oxygen stresses. FEMS microbiology letters, 284(1).
BIO5 Collaborators
Scott A Boitano, Katrina M Miranda

Bordetella bronchiseptica can establish prolonged airway infection consistent with a highly developed ability to evade mammalian host immune responses. Upon initial interaction with the host upper respiratory tract mucosa, B. bronchiseptica are subjected to antimicrobial reactive nitrogen species (RNS) and reactive oxygen species (ROS), effector molecules of the innate immune system. However, the responses of B. bronchiseptica to redox species at physiologically relevant concentrations (nM-microM) have not been investigated. Using predicted physiological concentrations of nitric oxide (NO), superoxide and hydrogen peroxide (H2O2) on low numbers of CFU of B. bronchiseptica, all redox active species displayed dose-dependent antimicrobial activity. Susceptibility to individual redox active species was significantly increased upon introduction of a second species at subantimicrobial concentrations. An increased bacteriostatic activity of NO was observed relative to H2O2. The understanding of Bordetella responses to physiologically relevant levels of exogenous RNS and ROS will aid in defining the role of endogenous production of these molecules in host innate immunity against Bordetella and other respiratory pathogens.

Espey, M. G., Miranda, K. M., Feelisch, M., Fukuto, J., Grisham, M. B., Vitek, M. P., & Wink, D. A. (2000). Mechanisms of cell death governed by the balance between nitrosative and oxidative stress. Annals of the New York Academy of Sciences, 899, 209-221.

PMID: 10863541;Abstract:

Many cellular functions in physiology are regulated by the direct interaction of NO with target biomolecules. In many pathophysiologic and toxicologic mechanisms, NO first reacts with oxygen, superoxide or other nitrogen oxides to subsequently elicit indirect effects. The balance between nitrosative stress and oxidative stress within a specific biological compartment can determine whether the presence of NO will be ultimately deleterious or beneficial. Nitrosative stress can be defined primarily through reactions mediated by N2O3, a reactive nitrogen oxide species generated by high fluxes of NO in an aerobic environment. In contrast, oxidative stress is mediated primarily by superoxide and peroxides. In addition to reactive oxygen species, several reactive nitrogen oxide species such as peroxynitrite, nitroxyl, and nitrogen dioxide can also impose oxidative stress to a cell. We here describe how the mechanisms of cell death are interwoven in the balance between the different chemical intermediates involved in nitrosative and oxidative stress.

Pagliaro, P., Mancardi, D., Rastaldo, R., Penna, C., Gattullo, D., Miranda, K. M., Feelisch, M., Wink, D. A., Kass, D. A., & Paolocci, N. (2003). Nitroxyl affords thiol-sensitive myocardial protective effects akin to early preconditioning. Free Radical Biology and Medicine, 34(1), 33-43.

PMID: 12498977;Abstract:

Nitric oxide (NO) donors mimic the early phase of ischemic preconditioning (IPC). The effects of nitroxyl (HNO/NO-), the one-electron reduction product of NO, on ischemia/reperfusion (I/R) injury are unknown. Here we investigated whether HNO/NO-, produced by decomposition of Angeli's salt (AS; Na2N2O3), has a cardioprotective effect in isolated perfused rat hearts. Effects were examined after intracoronary perfusion (19 min) of either AS (1 μM), the NO donor diethylamine/NO (DEA/NO, 0.5 μM), vehicle (100 nM NaOH) or buffer, followed by global ischemia (30 min) and reperfusion (30 min or 120 min in a subset of hearts). IPC was induced by three cycles of 3 min ischemia followed by 10 min reperfusion prior to I/R. The extent of I/R injury under each intervention was assessed by changes in myocardial contractility as well as lactate dehydrogenase (LDH) release and infarct size. Postischemic contractility, as indexed by developed pressure and dP/dtmax, was similarly improved with IPC and pre-exposure to AS, as opposed to control or DEA/NO-treated hearts. Infarct size and LDH release were also significantly reduced in IPC and AS groups, whereas DEA/NO was less effective in limiting necrosis. Co-infusion in the triggering phase of AS and the nitroxyl scavenger, N-acetyl-L-cysteine (4 mM) completely reversed the beneficial effects of AS, both at 30 and 120 min reperfusion. Our data show that HNO/NO- affords myocardial protection to a degree similar to IPC and greater than NO, suggesting that reactive nitrogen oxide species are not only necessary but also sufficient to trigger myocardial protection against reperfusion through species-dependent, pro-oxidative, and/or nitrosative stress-related mechanisms. © 2002 Elsevier Science Inc.

Thomas, D., Espey, M., Vitek, M., Miranda, K., & Wink, D. (2001). Protein nitration is mediated by heme and free metals through Fenton-type chemistry: An alternative to the NO/O-2(-) reaction. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 99(20), 12691-12696.

The chemical origins of nitrated tyrosine residues (NT) formed in proteins during a variety of pathophysiological conditions remain controversial. Although numerous studies have concluded that NT is a signature for peroxynitrite (ONOO-) formation, other works suggest the primary involvement of peroxidases. Because metal homeostasis is often disrupted in conditions bearing NT, the role of metals as catalysts for protein nitration was examined. Cogeneration of nitric oxide (NO) and superoxide (O-2(-)), from spermine/NO (2.7 muM/min) and xanthine oxidase (1-28 muM O-2(-)/min), respectively, resulted in protein nitration only when these species were produced at approximately equivalent rates. Addition of ferriprotoporphyrin IX (hemin) to this system increased nitration over a broad range of O-2(-) concentrations with respect to NO. Nitration in the presence of superoxide dismutase but not catalase suggested that ONOO- might not be obligatory to this process. Hemin-mediated NT formation required only the presence of NO2- and H2O2, which are stable end-products of NO and O-2(-) degradation. Ferrous, ferric, and cupric ions were also effective catalysts, indicating that nitration is mediated by species capable of Fenton-type chemistry. Although ONOO- can nitrate proteins, there are severe spatial and temporal constraints on this reaction. In contrast, accumulation of metals and NO2- subsequent to NO synthase activity can result in far less discriminate nitration in the presence of an H2O2 source. Metal catalyzed nitration may account for the observed specificity of protein nitration seen under pathological conditions, suggesting a major role for translocated metals and the labilization of heme in NT formation.

Miranda, K., Nims, R., Thomasa, D., Espey, M., Citrin, D., Bartberger, M., Paolocci, N., Fukuto, J., Feelisch, M., & Wink, D. (2002). Comparison of the reactivity of nitric oxide and nitroxyl with heme proteins - A chemical discussion of the differential biological effects of these redox related products of NOS. JOURNAL OF INORGANIC BIOCHEMISTRY, 93(1-2), 52-60.

Investigations on the biological effects of nitric oxide (NO) derived from nitric oxide synthase (NOS) have led to an explosion in biomedical research over the last decade. The chemistry of this diatomic radical is key to its biological effects. Recently, nitroxyl (HNO/NO-) has been proposed to be another important constituent of NO biology. However, these redox siblings often exhibit orthogonal behavior in physiological and cellular responses. We therefore explored the chemistry of NO and HNO with heme proteins in different redox states and observed that HNO favors reaction with ferric heme while NO favors ferrous, consistent with previous reports. Further results show that HNO and NO were equally effective in inhibiting cytochrome P450 activity, which involves ferric and ferrous complexes. The differential chemical behavior of NO and HNO toward heme proteins provides insight into mechanisms of activity that not only helps explain some of the opposing effects observed in NOS-mediated events, but offers a unique control mechanism for the biological action of NO. Published by Elsevier Science Inc.