Bleomycin induces upregulation of lysyl oxidase in cultured human fetal lung fibroblasts.
OBJECTIVE
To investigate the mechanism of bleomycin (BLM)-induced pulmonary fibrosis.


METHODS
Cultured human fetal lung fibroblast (HLF) cells were exposed to bleomycin (BLM) at 0-30 microg/mL for 24 h. Western blot analysis was used to detect lysyl oxidase (LO) protein expression. Real-time RT-PCR was used to detect LO mRNA level. LO catalytic activity was measured using diaminopentane as a substrate and Amplex red as a hydrogen peroxide probe. Copper (Cu) concentration was detected by flame atomic absorption spectrophotometry.


RESULTS
Exposure of HLF cells to BLM at 10 microg/mL and 30 microg/mL increased LO catalytic activity to 130% and 158% of the control in the conditioned media. The expression of LO mRNA was increased to 5.5-fold of the control in HLF cells exposure to BLM at 3 microg/mL. BLM at 3 microg/mL also increased the expression of 46 kDa preproLO, 50 kDa proLO and 32 kDa mature LO to 219%, 130%, and 135% of the control, respectively. The Cu concentrations in conditioned media of cultured HLF cells exposed to BLM (10 and 30 microg/mL) were increased significantly to 1.48 and 2.46-fold of the control, respectively.


CONCLUSIONS
Bleomycin induces upregulation of LO in cultured human fetal lung fibroblasts, which may be the mechanism of bleomycin-induced pulmonary fibrosis.
Chen
Li-jun
LJ
Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510089, China. chenlij@mail.sysu.edu.cn
Li
Wan-de
WD
Li
Shi-feng
SF
Su
Xing-wen
XW
Lin
Guang-yun
GY
Huang
Yi-jun
YJ
Yan
Guang-mei
GM
D000629:Aminopropionitrile / Q000494:pharmacology; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D001761:Bleomycin / Q000494:pharmacology*; D002460:Cell Line; D003300:Copper / Q000378:metabolism; D005333:Fetus / Q000166:cytology; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000166:cytology; D008249:Protein-Lysine 6-Oxidase / Q000235:genetics* / Q000378:metabolism; D011658:Pulmonary Fibrosis / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
D000903:Antibiotics, Antineoplastic; D001761:Bleomycin; D000629:Aminopropionitrile; D003300:Copper; D008249:Protein-Lysine 6-Oxidase