Effects of Astragaloside IV Against the TGF-β1-Induced Epithelial-to-Mesenchymal Transition in Peritoneal Mesothelial Cells by Promoting Smad 7 Expression.
OBJECTIVE
To investigate the effect of Astragaloside IV (AS-IV) on the regulation of the TGF-β1/Smad signaling pathway in peritoneal mesothelial cells with an epithelial-to-mesenchymal transition (EMT).


METHODS
EMT of human peritoneal mesothelial cells (HMrSV5) was induced using 2 ng/ml TGF-β1. Cells were randomly divided into a vehicle group, a vehicle group with AS-IV, a TGF-β1 treated group, and a TGF-β1 treated group receiving varied doses of AS-IV or NAC. Real-time quantitative PCR and western blot were used to detect the expression of genes and proteins associated with the TGF-β1/Smad signaling pathway and EMT. DCFH-DA was used to detect the generation of ROS in HMrSV5 cells, and a transwell migration assay was used to verify the capacity of AS-IV to inhibit EMT in HMrSV5 cells. Lentiviruses were used as carriers for the overexpression or knockdown of the Smad7 gene.


RESULTS
Expression levels of E-cadherin (epithelial marker) was decreased and vimentin, α-SMA (EMT markers) and collagen I (extracellular matrix protein) phospho-Smad2/3, Snail1 and Snail2 was increased significantly in the TGF-β1-treated HMrSV5 cells. AS-IV was associated with downregulated expression of vimentin and phospho-Smad2/3 in a dose-dependent manner, while the expression of Smad7 increased. Silenced or forced expression of Smad7 verified its role in the inhibitory effect of AS-IV on TGF-β1-induced EMT in HMrSV5 cells.


CONCLUSIONS
AS-IV effectively promotes the upregulation of Smad7 in the TGF-β1/Smad signaling pathway during the EMT of HMrSV5 cells, indicating its potential therapeutic effect for the control of PF.
First Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing, China.
Lu
L
Zhang
Zhenghong
Z
Li
Weiming
W
He
Lingdong
L
Xu
Jing
J
Wang
Jun
J
Shi
Meixiao
M
Sheng
D000199:Actins / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D004848:Epithelium / Q000187:drug effects*; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D012503:Saponins / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D051906:Smad7 Protein / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D014315:Triterpenes / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects; D014746:Vimentin / Q000378:metabolism
C541116:ACTA2 protein, human; D000199:Actins; D015820:Cadherins; D024042:Collagen Type I; C497806:SMAD7 protein, human; D012503:Saponins; D051906:Smad7 Protein; D053773:Transforming Growth Factor beta1; D014315:Triterpenes; D014746:Vimentin; C052064:astragaloside A