SH Randell, JY Liu, PC Ferriola, L Kaartinen, MM Doherty, CW Davis and P Nettesheim
Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, North Carolina, NC 27599, USA.

An airway epithelial mucous goblet cell line would be useful towards understanding mechanisms underlying the common problem of respiratory mucus hypersecretion. SPOC1 is a novel rat tracheal epithelial (RTE) cell line that developed cytologic features suggestive of mucous goblet cells when grown in tracheal grafts in vivo (Am. J. Respir. Cell Mol. Biol. 1995; 12:385-395). Our aims were to determine whether SPOC1 cells were capable of mucin synthesis and to directly compare mucin production by SPOC1 cells and RTE cells. Towards this end, we validated the use of monoclonal antibody (mAb) RTE11 (Exp. Lung Res. 1992; 18:323- 342) as an immunologic probe for rat airway secretory mucin. Our results strongly suggest that mAb RTE11 detects a carbohydrate antigen that is a sensitive and specific marker for rat tracheobronchial secretory mucin. SPOC1 cells in tracheal grafts in vivo contained granules with ultrastructural features similar to mucous granules in normal rat airway goblet cells and they were strongly stained by mAb RTE11. Retinoic acid (RA) and culture on porous supports are known to profoundly modify airway epithelial cell phenotype in vitro. Expression of several retinoid-responsive proteins was similar in cultured SPOC1 and primary RTE cells, but major differences in mucin production were noted. Primary RTE cells in vitro only made mucin when grown on porous supports in the presence of RA, whereas SPOC1 cells produced mucin when grown on plastic or glass surfaces and even in the absence of RA. Interestingly, RA enhanced mucin secretion by SPOC1 cells during the early plateau stage of culture but there were no differences due to RA late in the culture period. SPOC1 cells are capable of mucin production and will be a useful tool for studying select aspects of airway secretory cell differentiation and function.

This article has been cited by other articles:

				C. Ehre, Y. Zhu, L. H. Abdullah, J. Olsen, K. I. Nakayama, K. Nakayama, R. O. Messing, and C. W. Davis nPKC{varepsilon}, a P2Y2-R downstream effector in regulated mucin secretion from airway goblet cells Am J Physiol Cell Physiol, November 1, 2007; 293(5): C1445 - C1454. [Abstract] [Full Text] [PDF]

				L. H. Abdullah and C. W. Davis Regulation of airway goblet cell mucin secretion by tyrosine phosphorylation signaling pathways Am J Physiol Lung Cell Mol Physiol, September 1, 2007; 293(3): L591 - L599. [Abstract] [Full Text] [PDF]

				C. Ehre, A. H. Rossi, L. H. Abdullah, K. De Pestel, S. Hill, J. C. Olsen, and C. W. Davis Barrier role of actin filaments in regulated mucin secretion from airway goblet cells Am J Physiol Cell Physiol, January 1, 2005; 288(1): C46 - C56. [Abstract] [Full Text] [PDF]

				A. H. Rossi, P. R. Sears, and C. W. Davis Ca2+ dependency of 'Ca2+-independent' exocytosis in SPOC1 airway goblet cells J. Physiol., September 1, 2004; 559(2): 555 - 565. [Abstract] [Full Text] [PDF]

				J. E. Foster, K. Gott, M. R. Schuyler, W. Kozak, and Y. Tesfaigzi LPS-induced neutrophilic inflammation and Bcl-2 expression in metaplastic mucous cells Am J Physiol Lung Cell Mol Physiol, August 1, 2003; 285(2): L405 - L414. [Abstract] [Full Text] [PDF]

				L. H. Abdullah, J. T. Bundy, C. Ehre, and C. W. Davis Mucin secretion and PKC isoforms in SPOC1 goblet cells: differential activation by purinergic agonist and PMA Am J Physiol Lung Cell Mol Physiol, July 1, 2003; 285(1): L149 - L160. [Abstract] [Full Text] [PDF]

				J. D. Conway, T. Bartolotta, L. H. Abdullah, and C. W. Davis Regulation of mucin secretion from human bronchial epithelial cells grown in murine hosted xenografts Am J Physiol Lung Cell Mol Physiol, June 1, 2003; 284(6): L945 - L954. [Abstract] [Full Text] [PDF]

				K. B. Adler and Y. Li Airway Epithelium and Mucus . Intracellular Signaling Pathways for Gene Expression and Secretion Am. J. Respir. Cell Mol. Biol., October 1, 2001; 25(4): 397 - 400. [Full Text] [PDF]

				M. V. Fanucchi, J. R. Harkema, C. G. Plopper, and J. A. Hotchkiss In Vitro Culture of Microdissected Rat Nasal Airway Tissues Am. J. Respir. Cell Mol. Biol., June 1, 1999; 20(6): 1274 - 1285. [Abstract] [Full Text]

				C. E. Scott, L. H. Abdullah, and C. W. Davis Ca2+ and protein kinase C activation of mucin granule exocytosis in permeabilized SPOC1 cells Am J Physiol Cell Physiol, July 1, 1998; 275(1): C285 - C292. [Abstract] [Full Text] [PDF]

				M. T. Borchers, S. E. Wert, and G. D. Leikauf Acrolein-induced MUC5ac expression in rat airways Am J Physiol Lung Cell Mol Physiol, April 1, 1998; 274(4): L573 - L581. [Abstract] [Full Text] [PDF]