Scott A Boitano
Associate Research Scientist, Respiratory Sciences
Professor, BIO5 Institute
Professor, Cellular and Molecular Medicine
Professor, Physiological Sciences - GIDP
Professor, Physiology
Primary Department
Department Affiliations
(520) 626-2105
Research Interest
Dr. Scott Boitano Ph.D., is a Professor of Physiology, Cellular and Molecular Medicine, the BIO5 Institute and Associate Research Scientist of the Arizona Respiratory Center. Dr. Boitano received a B.S. in Plant Biology from University of California; Berkeley and a Ph.D. in Genetics & Cell Biology from Washington State University. Dr. Boitano’s primary research interest is in cell respiration. This encompasses the analysis and observation of cell physiology, cell-cell communications and cell-pathogen interactions. Dr. Boitano’s research pertains to the upper airway epithelium is an active cellular layer with ciliary movement to clear materials, the ability to secrete inflammatory effectors, and a biological barrier function that helps protect against pathogenic microorganisms, foreign insults and injury. Although much is known concerning the microbial genetics and microbial signaling of infection by Bordetella, relatively little is known about host cell pathology after exposure to Bordetella. Individuals have a primary tissue culture system that serves as an in vitro model of airway cell signaling and communication, and a battery of B. bronchiseptica strains, some of which are mutant in key factors shown to inhibit their ability to establish infection in animal models. His research goal is to define specific pathogen factors that alter host cell physiology to initiate or overcome host cell defense. The Boitano lab also analyzes the layers of the alveoli of the distal mammalian lung. Minimal information is known about this subject and Dr. Boitano believes that this model system for alveolar intercellular communication could expedite the formulating and testing of new medical treatments for dysfunctional alveolar cell physiology that underlies specific airway conditions following disease, insult and injury in the lung.

Publications

Kurzius-Spencer, M., Foster, K., Littau, S., Richey, K. J., Clark, B. M., Sherrill, D., Boitano, S., Caruso, D. M., & Burgess, J. L. (2015). Tracheobronchial protease inhibitors, body surface area burns, and mortality in smoke inhalation. Journal of burn care & research : official publication of the American Burn Association, 30(5), 824-31.
BIO5 Collaborators
Scott A Boitano, Jefferey L Burgess

The objective of this study was to assess tracheobronchial protease inhibitor concentrations longitudinally and determine whether initial concentrations predict subsequent lung injury and mortality in intubated burn victims. Tracheobronchial suction fluid was collected every 2 hours for 36 hours. Alpha-1-antitrypsin (AAT), secretory leukocyte peptidase inhibitor (SLPI), alpha-2-macroglobulin (A2M), and cell and differential counts were assayed. Partial pressure of oxygen in arterial blood/fraction of inspired oxygen (PaO2/FIO2) and peak airway pressure (PAP) were recorded for 72 hours. Standard statistics were used to evaluate cross-sectional relationships; random coefficient (mixed) models were used to evaluate temporal trends in marker concentrations and relation to clinical outcomes. Among 29 patients, 24 (83%) developed hypoxemia (PaO2/FIO2 35% TBSA burn (P = .010 and .033, respectively), when compared with patients with less severe burns. However, patients with increased A2M in combination with >35% TBSA burn had a 6-fold (95% CI: 1.8-20) increased relative risk of death. Tracheobronchial AAT and A2M levels were significantly lower in patients with more severe burns and increased over time. Initial SLPI levels predicted subsequent PAP. Increased early A2M in combination with extensive burn predicted early mortality.

Olsen, C. E., Liguori, A. E., Zong, Y., Lantz, R. C., Burgess, J. L., & Boitano, S. (2008). Arsenic upregulates MMP-9 and inhibits wound repair in human airway epithelial cells. American journal of physiology. Lung cellular and molecular physiology, 295(2), L293-302.
BIO5 Collaborators
Scott A Boitano, Jefferey L Burgess, Clark Lantz

As part of the innate immune defense, the polarized conducting lung epithelium acts as a barrier to keep particulates carried in respiration from underlying tissue. Arsenic is a metalloid toxicant that can affect the lung via inhalation or ingestion. We have recently shown that chronic exposure of mice or humans to arsenic (10-50 ppb) in drinking water alters bronchiolar lavage or sputum proteins consistent with reduced epithelial cell migration and wound repair in the airway. In this report, we used an in vitro model to examine effects of acute exposure of arsenic (15-290 ppb) on conducting airway lung epithelium. We found that arsenic at concentrations as low as 30 ppb inhibits reformation of the epithelial monolayer following scrape wounds of monolayer cultures. In an effort to understand functional contributions to epithelial wound repair altered by arsenic, we showed that acute arsenic exposure increases activity and expression of matrix metalloproteinase (MMP)-9, an important protease in lung function. Furthermore, inhibition of MMP-9 in arsenic-treated cells improved wound repair. We propose that arsenic in the airway can alter the airway epithelial barrier by restricting proper wound repair in part through the upregulation of MMP-9 by lung epithelial cells.

Sherwood, C. L., & Boitano, S. (2016). Airway epithelial cell exposure to distinct e-cigarette liquid flavorings reveals toxicity thresholds and activation of CFTR by the chocolate flavoring 2,5-dimethypyrazine. Respiratory research, 17(1), 57.

The potential for adverse respiratory effects following exposure to electronic (e-) cigarette liquid (e-liquid) flavorings remains largely unexplored. Given the multitude of flavor permutations on the market, identification of those flavor constituents that negatively impact the respiratory tract is a daunting task. In this study we examined the impact of common e-liquid flavoring chemicals on the airway epithelium, the cellular monolayer that provides the first line of defense against inhaled particulates, pathogens, and toxicants.

Boitano, S., Isakson, B. E., Seedorf, G. J., Lubman, R. L., Evans, W. H., & Boitano, S. A. (2003). Cell-cell communication in heterocellular cultures of alveolar epithelial cells. American journal of respiratory cell and molecular biology, 29(5).

The mammalian alveolar epithelium is composed of alveolar type I (AT1) and alveolar type II (AT2) cells that together coordinate tissue function. We used a heterocellular culture model of AT1 and AT2 cells to determine pathways for intercellular signaling between these two phenotypes. Gap junction protein (connexin) profiles of AT1 and AT2 cells in heterocellular cultures were similar to those seen in rat lung alveolar sections. Dye coupling studies revealed functional gap junctions between and among each cell phenotype. Localized mechanical stimulation resulted in propagated changes of intracellular Ca2+ to AT1 or AT2 cells independent of the stimulated cell phenotype. Ca2+ communication that originated after AT1 cell stimulation was inhibited by gap junction blockers, but not by an inhibitor of extracellular nucleotide signaling (apyrase). Conversely, Ca2+ communication after stimulation of AT2 cells was not significantly reduced by gap junction inhibitors. However, apyrase significantly reduced Ca2+ communication from AT2 to AT1 cells, but not from AT2 to AT2 cells. In conclusion, AT1 and AT2 cells have unique connexin profiles that allow for functional coupling and distinct intercellular pathways for coordination of Ca2+ signaling.

Boitano, S., Sherwood, C. L., Lantz, R. C., & Boitano, S. A. (2013). Chronic arsenic exposure in nanomolar concentrations compromises wound response and intercellular signaling in airway epithelial cells. Toxicological sciences : an official journal of the Society of Toxicology, 132(1).
BIO5 Collaborators
Scott A Boitano, Clark Lantz

Paracrine ATP signaling in the lung epithelium participates in a variety of innate immune functions, including mucociliary clearance, bactericide production, and as an initiating signal in wound repair. We evaluated the effects of chronic low-dose arsenic relevant to U.S. drinking water standards (i.e., 10 ppb [130nM]) on airway epithelial cells. Immortalized human bronchial epithelial cells (16HBE14o-) were exposed to 0, 130, or 330nM arsenic (as Na-arsenite) for 4-5 weeks and examined for wound repair efficiency and ATP-mediated Ca(2+) signaling. We found that chronic arsenic exposure at these low doses slows wound repair and reduces ATP-mediated Ca(2+) signaling. We further show that arsenic compromises ATP-mediated Ca(2+) signaling by altering both Ca(2+) release from intracellular stores (via metabotropic P2Y receptors) and Ca(2+) influx mechanisms (via ionotropic P2X receptors). To better model the effects of arsenic on ATP-mediated Ca(2+) signaling under conditions of natural exposure, we cultured tracheal epithelial cells obtained from mice exposed to control or 50 ppb Na-arsenite supplemented drinking water for 4 weeks. Tracheal epithelial cells from arsenic-exposed mice displayed reduced ATP-mediated Ca(2+) signaling dynamics similar to our in vitro chronic exposure. Our findings demonstrate that chronic arsenic exposure at levels that are commonly found in drinking water (i.e., 10-50 ppb) alters cellular mechanisms critical to airway innate immunity.