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Kevin Urak

Mentor: Paloma Giangrande, Ph.D.
Lab Room: 5202 MERF
Lab Phone: 319-384-3243

Neutralization of extracellular histones with nucleic acid aptamers for the treatment of critical illness

Multiple organ dysfunction syndrome (MODS) is an insidious and life threatening sequelae in patients suffering major trauma or illness. With prompt care patients with major trauma/illness can survive the initial injury, but soon other organs not directly affected by the original injury/illness may become dysfunctional. Breathing problems will develop that require placement on a ventilator, the kidneys will stop working requiring dialysis, and the patient will bleed from every orifice. Coordinated efforts in the intensive care unit (ICU) may reverse MODS at great cost, but there is currently no treatment to prevent MODS. Of those that develop MODS (200,000 case/year in the US), the risk of death is 40%. The most common organ involved in MODS is the lung (referred to as acute respiratory distress syndrome or ARDS). Trauma, smoke inhalation, burns, radiation, severe infection and blood transfusions can each cause ARDS and lead to acute lung injury (ALI). Only recently have investigators recognized that there is a common element to these conditions: damaged tissues releasing histones into the circulation. Histones are basic proteins found in chromatin. They normally reside in the nucleus of the cell and partner with DNA. However, when released from dying cells, histones have toxic effects on the lungs and other organs. We hypothesized that neutralization of extracellular histones with nucleic acid aptamers (anionic molecules) can prevent the morbidity and mortality associated with MODS/ARDS. We have employed Systemic Evolution of Ligands by Exponential Enrichment (SELEX) technology to identify RNA aptamers that bind with high affinity (low nM-pM range) and specificity to those histones (H3 and H4) known to cause MODS/ARDS but not to other proteins present in blood or on cells. We confirmed that histones H3/H4 induce pronounced platelet aggregation, which can be inhibited with the addition of the selected RNA aptamers. Furthermore, we demonstrate that histone-induced cytotoxicity can be reversed by treatment with the RNA aptamers both in vitro (lung-derived endothelial and epithelial cells) and in vivo in a mouse model of MODS/ARDS. Current efforts are focused on evaluating and the efficacy and safety of these RNA bio-drugs in other established murine models of MODS/ARDS (e.g. inhalation lung injury and influenza). In conclusion, we present robust preclinical data on a novel class of therapeutics against circulating histones that may be potentially effective in a wide-variety of common clinical conditions with high degree of morbidity, mortality and expense and for which, there is currently no effective treatment thus, establishing a paradigm change in the treatment of critically ill patients.


Urak, K. T., Shore, S., Rockey, W. M., Chen, S. J., McCaffrey, A. P., & Giangrande, P. H. (2016). In vitro RNA SELEX for the generation of chemically-optimized therapeutic RNA drugs. Methods.

Jung, U., Urak, K., Veillette, M., Nepveu-Traversy, M. É., Pham, Q. T., Hamel, S. & Berthoux, L. (2015). Preclinical Assessment of Mutant Human TRIM5α as an Anti-HIV-1 Transgene. Human gene therapy, 26(10), 664-679.


Urak K, Giangrande P, Miller F (March 2015) Neutralization of extracellular histones with nucleic acid aptamers for the treatment of critical illness. Poster Presentation, Research Day Internal Medicine, Iowa City, IA

Kruspe S, Dickey DD, Urak KT, Blanco GN, Miller MJ, Clark KC, Burghardt E, Gutierrez WR, Phadke SD, Kamboj S, Ginader T, Smith BJ, Grimm SK, Schappet J, Ozer H, Thomas A, McNamara JO 2nd, Chan CH, Giangrande PH. Rapid and Sensitive Detection of Breast Cancer Cells in Patient Blood with Nuclease-Activated Probe Technology. Mol Ther Nucleic Acids. 2017 Sep 15;8:542-557. doi: 10.1016/j.omtn.2017.08.004. Epub 2017 Aug 12. PubMed PMID: 28918054; PubMed Central PMCID: PMC5577414.

Honors and Awards

  • Cleary International Dissertation Research Fellowship, 2018
  • American Heart Association Predoctoral fellowship, 2017-2018
  • Student Innovator Award, 2017
  • Excellence in Research Award, 2017