|Eduardo R Lazarowski, PhD, Research Associate Professor|
Extracellular nucleotides and nucleosides regulate mucociliary clearance (MCC) activities via activation of airway epithelial purinergic receptors, i.e., ATP/UTP-sensing P2Y2 receptor and the A2B adenosine receptor (Fig. 1). The Lazarowski’s lab studies the molecular basis and pathophysiological consequences of nucleotide release in the lung. Combining luminometry with radio-enzymatic- and HPLC-based techniques, we quantify adenine and uridine nucleotides and nucleotide sugars in lung secretions with nanomolar sensitivity. Using genetic approaches that knockdown nucleotide release pathway components, we have identified conductive and vesicular mechanisms involved in the release of nucleotides and studies are in progress to assess the contribution of these mechanisms to lung functions.
Mechanisms of nucleotide release
Airway epithelial cells release ATP, UTP, and UDP-sugars constitutively and in response to biochemical and physical challenges. Studies in the lab address the contribution pannexin 1 (Fig. 1), the vesicular nucleotide transporter VNUT (Fig. 1), and Golgi resident UDP-sugar transporters (Figs. 2) to the release of nucleotides from normal epithelial cells as well as mucin hypersecreting and inflamed epithelia (Seminario-Vidal et al., 2011; Sesma et al., 2012; Okada et al, 2013). Current studies investigate how these nucleotide channels and transporters contribute to airway surface liquid production and mucin hydration.
Nucleotides and airway inflammation
Chronic mucin hypersecretion, airway obstruction, and neutrophil inflammation are pathophysiological features of cystic fibrosis (CF) lung disease, and bronchoalveolar lavage fluids (BALFs) from patients with CF exhibit robust accumulation of UDP-sugars (Sesma et al., 2009). UDP-glucose is a potent naturally occurring agonist at the P2Y14 receptor, which is abundantly expressed in neutrophils and other inflammatory cells (Lazarowski and Harden 2015; Fig. 2). We have recently demonstrated that UDP-glucose promotes P2Y14R-dependent neutrophil chemotaxis in vitro (Sesma et al., 2013, Barrett et al., 2014). Thus, an additional area of interest in the Lazarowski’s lab is on defining the functional properties of the neutrophil P2Y14 receptor and to determine the potential contribution of released UDP-sugars to lung inflammation.
Nucleotides as potential biomarkers of chronic lung diseases
Recent studies in collaboration with clinical researchers within UNC revealed that abnormal regulation of mucous hydration in chronic bronchitis is associated with altered levels of extracellular nucleotides/nucleosides (Anderson et al., 2015). Studies are underway to Identifying extracellular nucleotide/nucleoside distribution and release/metabolism patterns associated with chronic lung diseases and to assess the impact of tobacco smoke on airway surface liquid nucleotide homeostasis.
Figure 1. Purinergic control of MCC functions. A2B receptors (A2BR) on ciliated cells impart cyclic AMP-regulated CFTR Cl- channel activity, while P2Y2 receptors (P2Y2-R) promote Cl- secretion (via both CaCC/TMEM16 and PKC-mediated CFTR activation) and inhibit Na+ absorption. P2Y2-Rs also are expressed on goblet cells, promoting mucin secretion. The plasma membrane pannexin 1 (Panx1) contributes to the release of ATP (and UTP) from ciliated cells. ATP and to a greater extent ADP and AMP also are released from mucin granules (MGs), promoting paracrine activation of A2BR and ion/water secretion on ciliated cells. The vesicular nucleotide transporter VNUT regulates ATP transport into mucin granules. Nucleotides and adenosine are metabolized by ecto nucleotidases and adenosine (ADO) deaminase (ADA).
Figure 2. Release and actions of UDP-sugars. UDP-glucose (UDPG) and other UDP-sugars enter the secretory pathway via ER/Golgi-resident SLC35 transporters. Golgi-derived vesicles are a source of UDP-sugars in specialized granules susceptible to exocytosis. The P2Y14R couples to Gi, thus promoting Gαi- and Gβγ-mediated responses.
Eduardo R Lazarowski, PhD, Research Associate Professor
Education and Training
(1975) BS, Clinical Chemistry, University of Buenos Aires, Argentina.
(1978) MS, Biochemistry, University of Buenos Aires, Argentina.
(1989) PhD, Biochemistry, University of Buenos Aires, Argentina.
(1986-990) Visiting Fellow, The Wellcome Research Laboratories, NC, USA.
(1990-1994) Post-doctoral fellow. Department of Medicine. UNC Chapel Hill.
(1994-1998) Research Associate. Cystic Fibrosis Center and Department of Pharmacology, UNC Chapel Hill.
(1998-2004) Research Assistant Professor. Department of Medicine, UNC Chapel Hill.
(2004-present) Research Associate Professor. Department of Medicine, UNC Chapel Hill.
Professional Societies, Editorial Appointments, and Committees
(2004- present) Editorial Board of Purinergic Signaling. Kluwer Academic Publishers.
(2004- present) American Society of Biochemistry and Molecular Biology.
(2004) Organizing Committee of the 4th International Symposium of Nucleosides and Nucleotides. Purines 2004. Chapel Hill, NC.
(2011) Associate Faculty Member of Faculty of 1000.
Selected Recent Publications
Please see Pubmed feed in the righthand column for more links to current publications.
- Anderson W. H, Coakley R. D., Button B., Henderson A. G., Zeman K. L., Alexis N. E., Peden D. B., Lazarowski E. R., Davis C. W., Bailey S., Fuller F., Almond M., Qaqish B., Bordonali E., Rubinstein M., Bennett W. D., Kesimer M., and Boucher R. C. The Relationship of Mucus Concentration (Hydration) to Mucus Osmotic Pressure and Transport in Chronic Bronchitis. Am. J. Resp. Cell. Mol. Bio. (2015, in press).
- Lazarowski E. R., and Harden T. K., UDP-sugars as extracellular signaling molecules: cellular and physiological consequences of P2Y14 receptor activation. Mol Pharmacol. 88:151–160 (2015).
- Barrett M. O, Sesma J. I., Ball C. B, Jayasekara P. S., Jacobson K. A., Lazarowski E. R., and Harden T. K. A selective high affinity antagonist of the P2Y14 receptor inhibits UDP-glucose-stimulated chemotaxis of human neutrophils. Mol. Pharmacol. 84:41-49 (2013).
- Okada S. F., Ribeiro C. P., Sesma J. I., Seminario-Vidal L., Abdullah L. H., van Heusden C., Lazarowski E. R., Boucher R. C. Inflammation Promotes Airway Epithelial ATP Release via Calcium-Dependent Vesicular Pathways. J Respir. Cell Mol. Biol. 49:814–820 (2013).
- Sesma J. I., Kreda S. M., Okada S. F., van Heusden C., Moussa L., Jones L. C., O’Neal K. M., Togawa N., Hiasa H., Moriyama Y., and Lazarowski E. R. The vesicular nucleotide transporter (VNUT) regulates the nucleotide content in airway epithelial mucin granules. Am. J. Physiol. Cell. Physiol. 304:C976-84 (2013).
- Lazarowski E. Vesicular and conductive mechanisms of nucleotide release. Purienrgic Signal. 8:359-73 (2012).
- Sesma J. I., Kreda S. M., Steinckwich-Besancon N., Dang H., García-Mata R., T., Harden T. K, and Lazarowski E. R. The UDP-sugar-sensing P2Y14 receptor promotes Rho-mediated signaling and chemotaxis in human neutrophils. Am. J. Physiol. Cell Physiol. 303:C490-8 (2012).
- Seminario-Vidal L, Okada S. F., Sesma J.I., Kreda S.M., van Heusden C.A., Zhu Z., Jones L., O'Neal W. K., Penuela S., Laird D. W., Boucher R. C., and Lazarowski E. R. Rho signaling regulates pannexin 1-mediated ATP release from airway epithelia. J Biol Chem. 286:26277–26286 (2011).
- Chekeni F. B., Elliot M. R, Sandilos J. K., Walk S. F., Kinchen J. M., Lazarowski E. R., Armstrong A. J., Penuela S., Laird D. W., Salvesen S., Isakson B. E., Bayliss D. A., Ravichandran K. S. Pannexin 1 channels mediate ‘find-me’ signal release and membrane permeability during apoptosis. Nature 467:863-867 (2010).
- Kreda S. M., Seminario-Vidal L, van Heusden C. A., O’Neal W., Jones L., Boucher R. C., and Lazarowski E. R. Receptor-promoted exocytosis of airway epithelial mucin granules containing a spectrum of adenine nucleotides. J. Physiol. 588:2255-2267 (2010).
- Sesma, J. I., Esther Jr, C. R., Kreda, S. M., Jones L., O’Neal, W., Nishihara, S., Nicholas, R. A., Lazarowski, E. R. ER/Golgi nucelotide sugar transporters contribute to the cellular release of UDP-sugar signaling molecules. J. Biol. Chem. 284:12572-12583 (2009).
- Seminario-Vidal, L., Kreda, S., Jones, L., O’Neal, W., Trejo, J., Boucher, R. C., and Lazarowski, E. R. Thrombin promotes release of ATP from lung epithelial cells through coordinated activation of Rho- and Ca2+-dependent signaling pathways. J. Biol. Chem. 284:20638-20648 (2009).
- Lazarowski, E. R., and Boucher, R. C. Purinergic receptors in airway epithelia. Current Opinion in Pharmacology 9:262-267 (2009).
National Institutes of Health (NIH)
|Eduardo Lazarowski, PhD, Research Associate Profesor||Juliana Sesma, PhD, Postdoctoral Research Associate||Catja VanHeusen, Research Specialist and Laboratory Manager|
The University of North Carolina at Chapel Hill
Campus Box #7248
Chapel Hill, NC 27599-7248
Phone: (919) 966-0991 (office)
Phone: (919) 966-7046 (lab)Email: email@example.com