Mucociliary functions of respiratory tract epithelium play a very important role in pulmonary defense. Vitamin A or its analogs (retinoids) is required for the expression of these differentiated functions. In vitamin A deficiency, the epithelium changes to a squamous keratinizing one (squamous metaplasia). Both in vivo and in vitro organ culture studies show that the addition of vitamin A or other retinoids can convert the squamous epithelium to a normal mucociliary one. Excess vitamin A can convert even the stratified skin epithelium to a one containing mucus-secreting granules (mucous cell metaplasia). However, the nature of mucociliary differentiation and the mechanism by which retinoid controls the expression of these differentiated functions are still unknown. An interdisciplinary approach is proposed to investigate the nature of retinoid-responsive mucous cell differentiation in cultured hamster tracheal epithelial (HTE) cells. We have developed a serum-free medium that permits the growth and differentiation of protease-dissociated respiratory tract epithelial cells, including HTE cells, on collagen gel substrata. Vitamin A or other retinoids is required in HTE culture to induce mucous cell differentiation and ciliogenesis. Based on the preliminary studies, it is proposed that retinoids regulate mucous cell differentiation, especially the synthesis of mucin core protein, apomucin, at the genetic level in the squamous basal cells. To test this hypothesis and examine the mechanisms of vitamin A regulation at the genetic and biochemical levels, it will be necessary to develop genetic and immunological probes for mucin. Development of these probes will be facilitated by the well-defined culture system for HTE cells. Monoclonal antibodies specific for hamster tracheal mucin and apomucin will be developed for monitoring the stages of mucin biosynthesis during the differentiation. cDNA probes to retinoid-responsive genes, in particular cDNA complementary to apomucin, will be isolated. The cDNA library of HTE cells cultured in the presence of retinoid will be developed and screened with oligonucleotide probes corresponding to apomucin sequence or vitamin A-responsive genes. Mabs will be used to immunoprecipitate polysome fractions enriched with apomucin mRNA. Furthermore, a recently developed biphasic culture chamber (the Whitcutt chamber) which enhances the polarity of differentiation of cultured HTE cells similar to in vivo, will be used to identify the precursor cell type involved in retinoid-reponsiove mucous cell differentiation in vitro.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL035635-01A2
Application #
3349689
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1987-04-01
Project End
1990-03-31
Budget Start
1987-04-01
Budget End
1988-03-31
Support Year
1
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Kao, Cheng-Yuan; Kim, Christy; Huang, Fei et al. (2008) Requirements for two proximal NF-kappaB binding sites and IkappaB-zeta in IL-17A-induced human beta-defensin 2 expression by conducting airway epithelium. J Biol Chem 283:15309-18
Chen, Yin; Hamati, Edward; Lee, Pak-Kei et al. (2006) Rhinovirus induces airway epithelial gene expression through double-stranded RNA and IFN-dependent pathways. Am J Respir Cell Mol Biol 34:192-203
Thai, Philip; Chen, Yin; Dolganov, Gregory et al. (2005) Differential regulation of MUC5AC/Muc5ac and hCLCA-1/mGob-5 expression in airway epithelium. Am J Respir Cell Mol Biol 33:523-30
Kao, Cheng-Yuan; Huang, Fei; Chen, Yin et al. (2005) Up-regulation of CC chemokine ligand 20 expression in human airway epithelium by IL-17 through a JAK-independent but MEK/NF-kappaB-dependent signaling pathway. J Immunol 175:6676-85
Wachi, Shinichiro; Yoneda, Ken; Wu, Reen (2005) Interactome-transcriptome analysis reveals the high centrality of genes differentially expressed in lung cancer tissues. Bioinformatics 21:4205-8
Kao, Cheng-Yuan; Chen, Yin; Thai, Philip et al. (2004) IL-17 markedly up-regulates beta-defensin-2 expression in human airway epithelium via JAK and NF-kappaB signaling pathways. J Immunol 173:3482-91
Harper, Richart; Xu, Changhong; Di, Peter et al. (2004) Identification of a novel MAGE D2 antisense RNA transcript in human tissues. Biochem Biophys Res Commun 324:199-204
Oslund, Karen L; Miller, Lisa A; Usachenko, Jodie L et al. (2004) Oxidant-injured airway epithelial cells upregulate thioredoxin but do not produce interleukin-8. Am J Respir Cell Mol Biol 30:597-604
Chen, Yin; Zhao, Yu Hua; Kalaslavadi, Tejas Baba et al. (2004) Genome-wide search and identification of a novel gel-forming mucin MUC19/Muc19 in glandular tissues. Am J Respir Cell Mol Biol 30:155-65
Di, Yuan-Pu; Harper, Richart; Zhao, Yuhua et al. (2003) Molecular cloning and characterization of spurt, a human novel gene that is retinoic acid-inducible and encodes a secretory protein specific in upper respiratory tracts. J Biol Chem 278:1165-73

Showing the most recent 10 out of 52 publications