[AP-1 regulates TGF-beta1-induced secretion of Type I collagen in human lung fibroblasts].
OBJECTIVE
To investigate the role of AP-1 in the secretion of Type I collagen in TGF-beta1-stimulated human lung fibroblasts.


METHODS
Human lung fibroblasts cell line (HLF-02) was cultured, and then stimulated with 10 microg/L TGF-beta1 at different time points. Curcumin was added into the culture medium to inhibit the AP-1 activity before incubating with TGF-beta1. AP-1 DNA binding activity was assayed by electrophoretic mobility shift assay (EMSA), and the expression of Type I collagen was detected by Western blot and RT-PCR.


RESULTS
TGF-beta1 could induce the transcription and secretion of Type I collagen in HLF-02 cells(P<0.05). TGF-beta1 could upregulate the AP-1 DNA binding activity ( P<0.05). Curcumin ( 5, 10, 15, and 20 micromol/L) could inhibit the AP-1 DNA binding activity in TGF-beta1-stimulated cells (the inhibition ratio was 17.1%, 17.6%, 24.2%, and 31.3%; P<0.05). Curcumin (5, 10, 15, and 20 micromol/L) could also inhibit the secretion of Type I collagen significantly (the inhibition ratio was 62.1%, 58.8%, 62.1%, and 59.6%; P<0.05).


CONCLUSIONS
AP-1 is responsible for the secretion of TGF-beta1-induced Type I collagen in human lung fibroblasts.
Hu
Yong-bin
YB
Department of Pathology, School of Basic Medicine, Central South University, Changsha 410013, China.
Zeng
Qing-fu
QF
Feng
De-yun
DY
Li
Xiang
X
Peng
Jin-wu
JW
D002460:Cell Line; D024042:Collagen Type I / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000166:cytology; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
D024042:Collagen Type I; D018808:Transcription Factor AP-1; D053773:Transforming Growth Factor beta1