Sterling K M, DiPetrillo T A, Kotch J P, Cutroneo K R
Cancer Res. 1982 Sep;42(9):3502-6.
Late-log-phase IMR-90 human fetal lung fibroblasts were incubated with bleomycin sulfate for 48 hr. The culture medium was removed and replaced with serum-free medium and [5-3H]proline. The cells were then incubated for increasing time intervals. The cells and culture medium were collected, and radioactive proline incorporated into collagen and noncollagen protein was determined. Intracellular collagen synthesis was selectively increased. Furthermore, polysomes isolated from bleomycin-treated cells synthesized significantly more collagen in the wheat germ lysate than did control polysomes. Prolyl hydroxylase activity was also increased significantly in the bleomycin-treated cells. Free and peptide-bound radioactive hydroxyproline in the cells and medium was greatly increased in bleomycin-treated cells, which indicates increased collagen degradation. The results demonstrate that, although collagen synthesis in lung fibroblasts is increased by bleomycin, the newly synthesized collagen is rapidly degraded in both the cell layer and the medium. This increased collagen degradation may be responsible for the remodeling which takes place during lung fibrosis.
将对数生长期后期的IMR-90人胎儿肺成纤维细胞与硫酸博来霉素孵育48小时。去除培养基，换成无血清培养基和[5-³H]脯氨酸。然后将细胞孵育不同的时间间隔。收集细胞和培养基，测定掺入胶原蛋白和非胶原蛋白中的放射性脯氨酸。细胞内胶原蛋白合成选择性增加。此外，从经博来霉素处理的细胞中分离出的多核糖体在麦胚裂解物中合成的胶原蛋白比对照多核糖体显著更多。经博来霉素处理的细胞中脯氨酰羟化酶活性也显著增加。在经博来霉素处理的细胞中，细胞和培养基中游离的和肽结合的放射性羟脯氨酸大大增加，这表明胶原蛋白降解增加。结果表明，虽然博来霉素可增加肺成纤维细胞中的胶原蛋白合成，但新合成的胶原蛋白在细胞层和培养基中均迅速降解。这种增加的胶原蛋白降解可能是肺纤维化过程中发生重塑的原因。
