Integrin beta1-mediated signaling is involved in transforming growth factor-beta2-promoted migration in human lens epithelial cells.
OBJECTIVE
Transforming growth factor-beta 2 (TGF-beta2) is a potent growth inhibitor and apoptosis inducer. However, typically TGF-beta2 loses its growth-inhibitory and apoptosis-inducing effects but stimulates the migratory capacity of epithelial cells. In this study, we investigate the possible involvement of integrin and integrin-mediated signaling in TGF-beta2-promoted migration and adhesion in human lens epithelial cells.


METHODS
A human lens epithelial cell line (HLE B-3) was treated with 100 pg/ml TGF-beta2 for 6 h, 12 h, and 24 h. In vitro wound healing assay and cell adhesion assay were performed to detect the effect of TGF-beta2 on HLEC adhesion and migration. Integrin beta1 expression changes in HLECs during the treatment of TGF-beta2 were detected in protein levels and mRNA levels using confocal microscopy, flow cytometric analysis, and real time quantitative reverse transcription polymerase chain reaction (RT-PCR). Focal adhesion kinase (FAK) activity was examined by FAK phosphorylation and total tyrosine phosphorylation during treatment with TGF-beta2 in HLEC. Production of endogenous TGF-beta2 was measured by ELISA assay.


RESULTS
In this study, we found that TGF-beta2 significantly stimulated cell adhesion and migration in HLECs. By immunofluorescence staining and western blotting, we observed that TGF-beta2 markedly enhanced the expression of integrin beta1 and the Tyr-phosphorylation of focal adhesion kinase (FAK). Real time quantitative RT-PCR also showed the mRNA level of integrin beta1 was upregulated. Neutralizing anti-integrin beta1 monoclonal antibody significantly (p<0.05) inhibited TGF-beta2-promoted HLEC adhesion and migration.


CONCLUSIONS
TGF-beta2 promoted HLEC adhesion and migration in vitro. Integrin beta1 and integrin-mediated signaling are necessary for TGF-beta2-promoted adhesion and migration in human lens epithelial cells.
Yao
Ke
K
Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou, China. xlren@zju.edu.cn
Tan
Jian
J
Ye
PanPan
P
Wang
KaiJun
K
Xu
Wen
W
ShenTu
XingChao
X
Tang
XiaJing
X
D000906:Antibodies / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology*; D005353:Fibronectins / Q000494:pharmacology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D007908:Lens, Crystalline / Q000166:cytology / Q000502:physiology*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D053781:Transforming Growth Factor beta2 / Q000494:pharmacology*; D014443:Tyrosine / Q000378:metabolism
D000906:Antibodies; D005353:Fibronectins; D019012:Integrin beta1; D012333:RNA, Messenger; D011994:Recombinant Proteins; D053781:Transforming Growth Factor beta2; D014443:Tyrosine; D051416:Focal Adhesion Protein-Tyrosine Kinases