title: VEGF suppresses epithelial-mesenchymal transition by inhibiting the expression of Smad3 and miR‑192, a Smad3-dependent microRNA.
abstract: Transforming growth factor-β1 (TGF-β1)‑induced epithelial‑mesenchymal transition (EMT) is one of the important cellular and molecular mechanisms involved in renal fibrosis. Smad3 and miR-192 (a Smad3-dependent microRNA) are involved in TGF-β1-mediated EMT. Vascular endothelial growth factor (VEGF) is a renal tubular epithelial survival factor. Therefore, in the present study, we investigated the role of Smad3 and miR‑192 in the effects of VEGF on TGF‑β1‑mediated tubular EMT. A human kidney cortex (HKC) cell line stably overexpressing VEGF (HKC-SOEV) was established. The normal HKC cells and HKC‑SOEV cells were treated with TGF-β1 (5 µg/l) or/and LY294002 (20 µmol/l) for 24 and 48 h (LY294002 blocks the effect of VEGF). The protein expression of Smad2, Smad3, Smad4 and phosphorylated Smad3 (p‑Smad3) were measured by western blot analysis. The expression of Smad3 and miR-192 was determined by real‑time PCR. E-cadherin and α-smooth muscle actin (α-SMA) expression was detected by western blot analysis and laser scanning confocal microscopy (LSCM). TGF-β1 was found to induce the expression of α-SMA in the HKC cells. TGF-β1 also induced Smad3, miR-192 and p-Smad3 expression, but suppressed E‑cadherin expression. However, in the HKC-SOEV cells, the expression levels of α-SMA, Smad3, miR-192 and p‑Smad3 upon TGF-β1 stimulation were significantly reduced. In these cells, the suppressive effect of TGF-β1 on E‑cadherin was also reduced. Importantly, treatment with LY294002 significantly diminished the effect of VEGF. VEGF suppressed Smad3 and miR‑192, and subsequently inhibited EMT induced by TGF-β1.
authors.affiliation: Peking Union Medical College Hospital, Beijing, People's Republic of China.
authors.forename: Jun-Ping
authors.initials: JP
authors.lastname: Hong
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Li
authors.forename: Ming-Xi
authors.initials: MX
authors.lastname: Li
authors.forename: Fa-Lei
authors.initials: FL
authors.lastname: Zheng
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology / Q000633:toxicity; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009025:Morpholines / Q000494:pharmacology / Q000633:toxicity; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D051900:Smad3 Protein / Q000235:genetics* / Q000378:metabolism; D051901:Smad4 Protein / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D015820:Cadherins; D002867:Chromones; C546783:MIRN192 microRNA, human; D035683:MicroRNAs; D009025:Morpholines; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051900:Smad3 Protein; D051901:Smad4 Protein; D042461:Vascular Endothelial Growth Factor A; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one