Bleomycin-induced synthesis of type I procollagen by human lung and skin fibroblasts in culture

• Published in: Biochimica et biophysica acta Vol. 631; no. 2; pp. 359 - 370
• Main Authors: Clark, Joan G., Starcher, Barry C., Uitto, Jouni
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.1980
• Subjects: Bleomycin; Bleomycin - pharmacology; Carbon Radioisotopes; Cells, Cultured; DNA - biosynthesis; Fibrosis; Human lung; Humans; Lung - metabolism; Procollagen - biosynthesis; Procollagen synthesis; Proline - metabolism; Protein Biosynthesis; Skin - metabolism; skin fibroblast; Stimulation, Chemical; Human lung; Bleomycin; skin fibroblast; Procollagen synthesis; Fibrosis; Hepes, N-2-hydroxyethylpiperazine- N′-2-ethanesulfonic acid; SDS, sodium dodecyl sulfate
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(80)90309-8

Bleomycin is a chemotherapeutic agent sometimes associated with pulmonary fibrosis and skin lesions in patients undergoing treatment. We examined the mechanisms of increased collagen deposition in bleomycin-induced fibrosis by incubating human lung and skin fibroblast cultures with [ 14C]proline; the synthesis of [ 14C]hydroxyproline relative to DNA or cell protein was taken as an index of procollagen formation. Procollagen synthesis by lung cells in the presence of 0.1 and 1.0 μg/ml bleomycin was significantly increased and similar results were obtained with skin fibroblasts. The relative synthesis of genetically distinct types of collagen was measured by isolating the newly synthesized type I and type III procollagens by DEAE-cellulose chromatography. The proportion of type III procollagen of total newly synthesized procollagen in control lung fibroblasts cultures was 17.4 ± 0.6% (mean ± S.E.) while the corresponding value in cells incubated in 1 μg/ml bleomycin wa 12.5 ± 0.6% ( n = 6, P < 0.01). Similar results were obtained when the ratios of newly synthesized type I and type III collagens were estimated by interrupted polyacrylamide disc gel electrophoresis in sodium dodecyl sulfate after a limited proteolytic digestion with pepsin. The results indicate that the increased procollagen synthesis induced by bleomycin in fibroblast cultures is predominantly directed towards the synthesis of type I procollagen.