Fluorofenidone suppresses epithelial-mesenchymal transition and the expression of connective tissue growth factor via inhibiting TGF-beta/Smads signaling in human proximal tubular epithelial cells.
OBJECTIVE
The present study was designed to investigate the potential effects and mechanism of fluorofenidone (AKF-PD) on transforming growth factor beta1 (TGF-beta1)-induced tubular epithelial-mesenchymal transition (EMT) and the expression of connective tissue growth factor (CTGF) in human proximal tubular epithelial cells.


METHODS
HK-2 cells were pretreated with AKF-PD, pirfenidone (PFD), Losartan, and SB431542 (an inhibitor of TGF-beta type I receptor). The pretreated HK-2 cells were subsequently co-treated with TGF-beta1 (5 ng/ml). The morphological changes of HK-2 cells were observed under an inverted microscope. Expression of alpha-SMA was detected by Western blot and immunofluorescence. The protein expression of ZO-1, fibronectin, CTGF, phosphorylated Smad2 (p-Smad2) and phosphorylated Smad3 (p-Smad3) were evaluated by Western blot.


RESULTS
Through down-regulation of p-Smad2 and p-Smad3 proteins, AKF-PD significantly inhibited protein expression of alpha-SMA, fibronectin, and CTGF. Meanwhile, the depressed ZO-1 expression and morphological changes induced by TGF-beta1 were attenuated by AKF-PD.


CONCLUSIONS
AKF-PD acts as an anti-fibrotic agent through blocking TGF-beta/Smads signaling and consequently inhibits TGF-beta1-induced EMT and CTGF expression in human proximal tubular epithelial cells.
Division of Nephrology, Xiangya Hospital, Central South University, Changsha, Hunan.
Qiongjing
Q
Yuan
Linghao
L
Wang
Fangfang
F
Zhang
Rui
R
Wang
Xiao
X
Fu
Zhangzhe
Z
Peng
Wangbin
W
Ning
Gaoyun
G
Hu
Zhaohe
Z
Wang
Lijian
L
Tao
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D015153:Blotting, Western; D002460:Cell Line; D055513:Connective Tissue Growth Factor / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005353:Fibronectins / Q000096:biosynthesis; D005455:Fluorescent Antibody Technique; D006801:Humans; D007202:Indicators and Reagents; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000187:drug effects; D019808:Losartan / Q000494:pharmacology; D011728:Pyridones / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000502:physiology*
C511655:5-methyl-1-(3-fluorophenyl)-2-(1H)-pyridone; D047228:Angiotensin II Type 1 Receptor Blockers; D005353:Fibronectins; D007202:Indicators and Reagents; D011728:Pyridones; D051785:Smad Proteins; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor; D019808:Losartan