DIVERSE CELLULAR TGF-BETA(1) AND TGF-BETA(3) GENE-EXPRESSION IN NORMAL HUMAN AND MURINE LUNG

A role for transforming growth factor-beta(1) (TGF-beta(1)) has been p roposed in lung development and in the pathogenesis of pulmonary disea se, However, previous studies have not delineated the cells expressing TGF-beta(1) in normal adult lung, nor compared its gene expression wi th that of other TGF-beta isoforms. We used digoxigenin-labelled ribop robes to localize TGF-beta(1) and TGF-beta(3) gene expression in norma l adult human and mouse lung. This procedure was technically simple, p roviding excellent resolution. TGF-beta(1) and TGF-beta(3) messenger r ibonucleic acid (mRNA) transcripts were detected in a wide variety of cells, In human lung, mRNA for both isoforms was localized to bronchio lar epithelium and alveolar macrophages. TGF-beta(1), but not TGF-beta (3) mRNA was detected in mesenchymal and endothelial cells, In murine tissue, TGF-beta(1), mRNA was localized to bronchiolar epithelium, Cla ra cells, mesenchymal cells, pulmonary endothelium and alveolar cells, including macrophages. TGF-beta(3) mRNA was similarly distributed but not detected in endothelium. In summary, using a nonisotopic techniqu e in lung tissue, we have detailed the cells expressing the transformi ng growth factor-beta(1) and beta(3) genes in human and murine lung, T here was widespread expression of these cytokines in normal lung consi stent with autocrine or paracrine roles in regulating cellular turnove r, immune defence and matrix protein metabolism.