Katrina M Miranda
Associate Professor, BIO5 Institute
Associate Professor, Chemistry and Biochemistry-Sci
Primary Department
Department Affiliations
(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.

Donzelli, S., Switzer, C. H., Thomas, D. D., Ridnour, L. A., Espey, M. G., Isenberg, J. S., Tocchetti, C. G., King, S. B., Lazzarino, G., Miranda, K. M., Roberts, D. D., Feelisch, M., & Wink, D. A. (2006). The activation of metabolites of nitric oxide synthase by metals is both redox and oxygen dependent: A new feature of nitrogen oxide signaling. Antioxidants and Redox Signaling, 8(7-8), 1363-1371.

PMID: 16910783;Abstract:

Nitrite (NO2-), NG-hydroxy-L-arginine (NOHA), and hydroxylamine (NH2OH) are products of nitric oxide synthase (NOS) activity and can also be formed by secondary reactions of nitric oxide (NO). These compounds are commonly considered to be rather stable and as such to be dosimeters of NO biosynthesis. However, each can be converted via metal-catalyzed reactions into either NO or other reactive nitrogen oxide species (RNOS), such as nitrogen dioxide (NO2) and nitroxyl (HNO), which have biologic activities distinct from those of the parent molecules. Consequently, certain aspects of tissue regulation controlled by RNOS may be dictated to a significant extent by metal-dependent reactions, thereby offering unique advantages for cellular and tissue regulation. For instance, because many metal-catalyzed reactions depend on the redox and oxygen status of the cellular environment, such reactions could serve as redox indicators. Formation of RNOS by metal-mediated pathways would confine the chemistry of these species to specific cellular sites. Additionally, such mechanisms would be independent both of NO and NOS, thus increasing the lifetime of RNOS that react with NO. Thus metal-mediated conversion of nitrite, NOHA, and NH2OH into biologically active agents may provide a unique signaling mechanism. In this review, we discuss the biochemistry of such reactions in the context of their pharmacologic and biologic implications. © Mary Ann Liebert, Inc.

Ridnour, L. A., Thomas, D. D., Mancardi, D., Donzelli, S., Paolocci, N., Pagliaro, P., Miranda, K. M., Krishna, M., Fukuto, J., Grisham, M. B., Mitchell, J. B., Espey, M. G., & Wink, D. A. (2004). Antioxidant properties of nitric oxide in cellular physiological and pathophysiological mechanisms. The implications of biological balance between NO and oxidative stress. Current Medicinal Chemistry: Anti-Inflammatory and Anti-Allergy Agents, 3(3), 181-188.

Abstract:

The function of nitric oxide (NO) in pathophysiology remains confounding as both protective and cytotoxic effects of NO have been demonstrated in many disease processes. Nitric oxide chemistry culminating in the generation of oxidative as well as nitrosative intermediates have generally been proposed as mediators of pathophysiology and have overshadowed the antioxidant capabilities of NO. However, the counteracting role of NO in providing a balance under conditions of oxidative and nitrosative stress has been underappreciated. The purpose of this review is the discussion of the role of NO as an antioxidant and interceptor of more potent reactive intermediates in normal physiology and disease. © 2004 Bentham Science Publishers Ltd.

Sidorkina, O., Espey, M. G., Miranda, K. M., Wink, D. A., & Laval, J. (2003). Inhibition of poly(ADP-ribose) polymerase (PARP) by nitric oxide and reactive nitrogen oxide species. Free Radical Biology and Medicine, 35(11), 1431-1438.

PMID: 14642390;Abstract:

The poly(ADP-ribose) polymerase (PARP) family of nuclear enzymes is involved in the detection and signaling of single strand breaks induced either directly by ionizing radiation or indirectly by the sequential action of various DNA repair proteins. Therefore, PARP plays an important role in maintaining genome stability. Because PARP proteins contain two zinc finger motifs, these enzymes can be targets for reactive nitrogen oxide intermediates (RNOS) generated as a result of nitric oxide (NO) biosynthesis in an aerobic environment. The effects of RNOS on the activity of purified PARP were examined using donor compounds. Both NO and nitroxyl (HNO) donors were found to be inhibitory in a similar time and concentration manner, indicating that PARP activity can be modified under both nitrosative and oxidative conditions. Moreover, these RNOS donors elicited comparable PARP inhibition in Sf21 insect cell extract and intact human MCF-7 cancer cells. The concentrations of donor required for 90% inhibition of PARP activity produce RNOS at a similar magnitude to those generated in the cellular microenvironment of activated leukocytes, suggesting that cellular scavenging of RNOS may not be protective against PARP modification and that inhibition of PARP may be significant under inflammatory conditions. © 2003 Elsevier Inc.

Kumars, M. R., Fukuto, J. M., Miranda, K. M., & Farmer, P. J. (2010). Reactions of HNO with heme proteins: New routes to HNO-heme complexes and insight into physiological effects. Inorganic Chemistry, 49(14), 6283-6292.

PMID: 20666387;PMCID: PMC2912650;Abstract:

The formation and interconversion of nitrogen oxides has been of interest in numerous contexts for decades. Early studies focused on gas-phase reactions, particularly with regard to industrial and atmospheric environments, and on nitrogen fixation. Additionally, investigation of the coordination chemistry of nitric oxide (NO) with hemoglobin dates back nearly a century. With the discovery in the early 1980s that NO is blosynthesized as a molecular signaling agent, the literature has been focused on the biological effects of nitrogen oxides, but the original concerns remain relevant. For instance, hemoglobin has long been known to react with nitrite, but this reductase activity has recently been considered to be important to produce NO under hypoxic conditions. The association of nitrosyl hydride (HNO; also commonly referred to as nitroxyl) with heme proteins can also produce NO by reductive nitrosylation. Furthermore, HNO is considered to be an intermediate in bacterial denitrification, but conclusive identification has been elusive. The authors of this article have approached the bioinorganic chemistry of HNO from different perspectives, which have converged because heme proteins are important biological targets of HNO. © 2010 American Chemical Society.