Ronald D. Balczon, Ph.D.
Postdoctoral Studies: Baylor College of Medicine and University of Alabama at Birmingham
Ph.D., Florida State University
My research is focused on the role of the microtubule cytoskeleton in health and disease. Our past research has investigated how microtubules maintain the pulmonary endothelial cell barrier and how disruption of microtubules leads to pulmonary edema. These studies have identified a critical role for the microtubule-associated protein tau in maintaining endothelial barrier function and have demonstrated that inhibition of tau activity leads to barrier breakdown and edema. Our more recent studies have focused on barrier disruption following infection with Pseudomonas aeruginosa. Pseudomonas aeruginosa infection is a principal cause of acute pneumonia that can progress to sepsis, acute lung injury, and death. During infection, Pseudomonas uses a type III secretion system to transfer bacterial exoenzymes into the cytoplasm of target cells. Our studies have shown that one of these exoenzymes, ExoY, targets tau resulting in defective microtubule dynamics, pulmonary endothelial breakdown, and edema. Studies in progress are investigating long-term effects of Pseudomonas infection on patient health and survival.
- Wu, S., Chen, H., Alexeyev, M.F., King, J.A.C., Moore, T.M., Stevens, T, and Balczon, R.D. 2007. Microtubule motors regulate ISOC activation necessary to increase endothelial cell permeability. J. Biol. Chem. 282:34801-34808.
- Prasain, N., Alexeyev, M., Balczon, R., and Stevens, T. 2009. Soluble adenylyl cyclase-dependent microtubule disassembly reveals a novel mechanism of endothelial cell retraction. Am. J. Physiol. Lung Cell Molec. Physiol. 297:L73-83. PMCID: PMC2711814.
- Ochoa, C.D., Stevens, T., and Balczon, R. 2011. Cold exposure reveals two populations of microtubules in pulmonary endothelia. Am. J. Physiol. Lung Cell Molec. Physiol. 300:L132-138.
- Sayner, S.L., Balczon, R., Frank, D.W., Cooper, D.M., and Stevens, T. 2011. Filamin A is a phosphorylation target of membrane but not cytosolic adenylyl cyclase activity. Am. J. Physiol. Lung Cell Molec. Physiol. 300:L132-138.
- Zeng, H., Pappas, C., Belser, J.A., Houser, K.V., Zhong, W., Wadford, D.A., Stevens, T., Balczon, R., Katz, J.M., and Tumpey, T.M. 2012. Human pulmonary microvascular endothelial cells support productive replication of highly pathogenic avian influenza viruses: possible involvement in the pathogenesis of human H5N1 virus infection. J. Virology 86:667-678.
- Ochoa, C.D., Alexeyev, M., Pastukh, V., Balczon, R., and Stevens, T. 2012. Pseudomonas aeruginosa exotoxin Y is a promiscuous cyclase that increases endothelial cell tau phosphorylation and permeability. J. Biol. Chem. 287:25407-25418.
- Balczon, R., Prasain, N., Ochoa, C., Prater, J., Zhu, B., Alexeyev, M., Sayner, S., Frank, D.W., and Stevens, T. 2013. Pseudomonas aeruginosa exotoxin Y-mediated tau hyperphosphorylation impairs microtubule assembly in pulmonary microvascular endothelial cells. PLoS One 8:e74343.
- Stevens, Tr., Ochoa, C., Morrow, K., Robson, M., Prasain, N., Zhou, C., Alvarez, D., Frank, D., Balczon, R., and Stevens, T. 2014. The Pseudomonas aeruginosa exotoxin Y impairs endothelial cell proliferation and vascular repair following lung injury. Am. J. Physiol. Lung Cell Molec. Physiol. 306:L915-L924.