Fuzheng Huayu recipe and vitamin E reverse renal interstitial fibrosis through counteracting TGF-beta1-induced epithelial-to-mesenchymal transition.
OBJECTIVE
To investigate the mechanism of action of Fuzheng Huayu recipe (FZHY) and vitamin E (Vit E) against renal interstitial fibrosis related to transforming growth factor-beta1 (TGF-beta1) mediated tubular epithelial-to-mesenchymal transition.


METHODS
Renal interstitial fibrosis was induced by administration of HgCl(2) at a dose of 8 mg/kg body weight once a day for 9 weeks. Rats were randomly divided into four groups: normal, model, FZHY, and Vit E group. Rats in the latter two groups were treated with the FZHY recipe and Vit E respectively. HK-2 cells were treated with TGF-beta1 for 24h, followed by incubation with either SB-431542 (a potent and specific inhibitor of TbetaR-I kinase) or FZHY drug-containing serum for another 24h. Hyp content in rat kidney tissue was assayed with Jamall's method and collagen deposition in kidney was visualized using Masson stain. Protein expression of TGF-beta1, TbetaR-I, Smad2, p-Smad2, Smad3, and p-Smad3 was analyzed by Western blotting. Protein expression and the location of Smad3 in kidney was assayed by immunohistochemistry, E-cadherin, cytokeratin 18 (CK-18), alpha-SMA and TGF-beta1 by immunofluorescent stain.


RESULTS
FZHY and Vit E inhibited renal collagen deposition and reduced Hyp content significantly. They upregulated E-cadherin protein expression and down-regulated the protein expression of alpha-SMA, TGF-beta1, p-Smad2, p-Smad3, and TbetaR-I. Lastly, they inhibited the nuclear translocation of Smad3 in fibrotic kidney tissue. FZHY drug-containing serum significantly upregulated the expression of CK-18 and down-regulated the expression of alpha-SMA, TbetaR-I, p-Smad2/3 in TGF-beta1 stimulated HK-2 cells.


CONCLUSIONS
The mechanism of action of FZHY and Vit E against renal interstitial fibrosis is related to the reversal of tubular EMT induced by TGF-beta1.
Wang
Qing-Lan
QL
Institute of Liver Diseases, Shuguang Hospital affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Yuan
Ji-Li
JL
Tao
Yan-Yan
YY
Zhang
Yue
Y
Liu
Ping
P
Liu
Cheng-Hai
CH
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001549:Benzamides; D001692:Biological Transport / Q000187:drug effects; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D003094:Collagen / Q000378:metabolism*; D004149:Dioxoles; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use; D004847:Epithelial Cells / Q000187:drug effects; D005355:Fibrosis; D005658:Fungi; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D053538:Keratin-18 / Q000378:metabolism; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007674:Kidney Diseases / Q000188:drug therapy; D008297:Male; D008648:Mesoderm / Q000187:drug effects; D008517:Phytotherapy; D010946:Plants, Medicinal; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology* / Q000627:therapeutic use
C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D048868:Adaptor Proteins, Signal Transducing; D001549:Benzamides; D015820:Cadherins; D004149:Dioxoles; D004365:Drugs, Chinese Herbal; D053538:Keratin-18; D053773:Transforming Growth Factor beta1; C532829:fuzheng huayu; D014810:Vitamin E; D003094:Collagen; D006909:Hydroxyproline