Scott A Boitano

Scott A Boitano

Professor, Physiology
Professor, Cellular and Molecular Medicine
Associate Research Scientist, Respiratory Sciences
Professor, Physiological Sciences - GIDP
Professor, BIO5 Institute
Member of the General Faculty
Member of the Graduate Faculty
Primary Department
Department Affiliations
Contact
(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

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.

Boitano, S., Flynn, A. N., Sherwood, C. L., Schulz, S. M., Hoffman, J., Gruzinova, I., & Daines, M. O. (2011). Alternaria alternata serine proteases induce lung inflammation and airway epithelial cell activation via PAR2. American journal of physiology. Lung cellular and molecular physiology, 300(4), L605-14.

Allergens are diverse proteins from mammals, birds, arthropods, plants, and fungi. Allergens associated with asthma (asthmagens) share a common protease activity that may directly impact respiratory epithelial biology and lead to symptoms of asthma. Alternaria alternata is a strong asthmagen in semiarid regions. We examined the impact of proteases from A. alternata on lung inflammation in vivo and on cleaving protease-activated receptor-2 (PAR(2)) in vitro. A. alternata filtrate applied to the airway in nonsensitized Balb/c mice induced a protease-dependent lung inflammation. Moreover, A. alternata filtrate applied to human bronchial epithelial cells (16HBE14o-) induced changes in intracellular Ca(2+) concentration ([Ca(2+)](i)), consistent with PAR(2) activation. These effects were blocked by heat inactivation or by serine protease inhibition of A. alternata filtrates, and mimicked by PAR(2) specific ligands SLIGRL-NH(2) or 2-furoyl-LIGRLO-NH(2), but not the PAR(1)-specific ligand TFLLR-NH(2). Desensitization of PAR(2) in 16HBE14o- cells with 2-furoyl-LIGRLO-NH(2) or trypsin prevented A. alternata-induced [Ca(2+)](i) changes while desensitization of PAR(1), PAR(3), and PAR(4) with thrombin had no effect on A. alternata-induced Ca(2+) responses. Furthermore, the Ca(2+) response to A. alternata filtrates was dependent on PAR(2) expression in stably transfected HeLa cell models. These data demonstrate that A. alternata proteases act through PAR(2) to induce rapid increases in human airway epithelial [Ca(2+)](i) in vitro and cell recruitment in vivo. These responses are likely critical early steps in the development of allergic asthma.

Sherwood, C. L., Liguori, A. E., Olsen, C. E., Lantz, R. C., Burgess, J. L., & Boitano, S. (2013). Arsenic compromises conducting airway epithelial barrier properties in primary mouse and immortalized human cell cultures. PloS one, 8(12), e82970.
BIO5 Collaborators
Scott A Boitano, Clark Lantz

Arsenic is a lung toxicant that can lead to respiratory illness through inhalation and ingestion, although the most common exposure is through contaminated drinking water. Lung effects reported from arsenic exposure include lung cancer and obstructive lung disease, as well as reductions in lung function and immune response. As part of their role in innate immune function, airway epithelial cells provide a barrier that protects underlying tissue from inhaled particulates, pathogens, and toxicants frequently found in inspired air. We evaluated the effects of a five-day exposure to environmentally relevant levels of arsenic {4μM [~300 μg/L (ppb)] as NaAsO2} on airway epithelial barrier function and structure. In a primary mouse tracheal epithelial (MTE) cell model we found that both micromolar (3.9 μM) and submicromolar (0.8 μM) arsenic concentrations reduced transepithelial resistance, a measure of barrier function. Immunofluorescent staining of arsenic-treated MTE cells showed altered patterns of localization of the transmembrane tight junction proteins claudin (Cl) Cl-1, Cl-4, Cl-7 and occludin at cell-cell contacts when compared with untreated controls. To better quantify arsenic-induced changes in tight junction transmembrane proteins we conducted arsenic exposure experiments with an immortalized human bronchial epithelial cell line (16HBE14o-). We found that arsenic exposure significantly increased the protein expression of Cl-4 and occludin as well as the mRNA levels of Cl-4 and Cl-7 in these cells. Additionally, arsenic exposure resulted in altered phosphorylation of occludin. In summary, exposure to environmentally relevant levels of arsenic can alter both the function and structure of airway epithelial barrier constituents. These changes likely contribute to the observed arsenic-induced loss in basic innate immune defense and increased infection in the airway.