The primary objective of this proposal is to characterize at the molecular level the mechanisms and factors involved in the deranged expression of the human interstitial collagen genes in lung fibrosis. Toward this end we will: a) Establish the nature of cis-acting elements that modulate the tissue-specific expression of the collagens in mesenchymal cells, b) Analyze the changes in transcription that result from the treatment of cultured lung fibroblasts with a variety of growth factors and cell mediators, c) Monitor the temporal and cellular expression of the collagen genes during the pathogenic progression of the fibrotic process in bleomycinindued animals, and d) Explore the involvement of structural sequences in the modulation of collagen mRNA translation. To achieve these goals, the 5' regions of four human collagen genes will be subjected to detailed functional analyses using chimeric plasmids transfected into cultured normal, and induced lung fibroblasts. The activity of specific transcriptional factors will be assessed by a variety of molecular techniques on cloned DNA segments, and related to possible changes in chromatin structure. Regulatory molecules will be isolated and characterized with regard to their nature, and interaction with genomic elements. In situ hybridization will be employed to monitor the selective expression of collagen genes in tissues derived from a fibrotic animal model. Finally, the rate of translation of appropriate collagen constructs will be assayed in vitro, and in vivo following sequence manipulation. The long term thrust of this work is to elucidate the biological complexity and heterogeneity of lung fibrosis as it relates to collagen accumulation. In addition to collagen pathogenesis, these investigations will be of relevance to our general understanding of how cellular factors regulate the expression of eukaryotic genes.
| Boast, S; Su, M W; Ramirez, F et al. (1990) Functional analysis of cis-acting DNA sequences controlling transcription of the human type I collagen genes. J Biol Chem 265:13351-6 |
| Ramirez, F; Boast, S; D'Alessio, M et al. (1990) Fibrillar collagen genes. Structure and expression in normal and diseased states. Ann N Y Acad Sci 580:74-80 |
| Ramirez, F; Boast, S; D'Alessio, M et al. (1989) Molecular pathobiology of human collagens. Connect Tissue Res 21:79-88;discussion 89 |
