title: Curcumin ameliorates epithelial-to-mesenchymal transition of podocytes in vivo and in vitro via regulating caveolin-1.
abstract: OBJECTIVE
  Epithelial-mesenchymal transition (EMT) is recognized to play a key role in diabetic nephropathy (DN). Curcumin, the main active component of turmeric extracted from the roots of the Curcuma longa plant, has been reported for its anti-fibrotic effects in kidney fibrosis. The purpose of our study was to investigate the effects of curcumin in reversing epithelial-to-mesenchymal transition (EMT) of podocytes in vivo and in vitro.
  
  
  METHODS
  In vivo streptozotocin (STZ)-induced diabetic rats received vehicle or curcumin, and podocytes were treated with high glucose (HG) in the presence or absence of curcumin in vitro. And we investigated the effect of curcumin on HG-induced phosphorylation of cav-1 on the stability cav-1 and β-catenin using immunoprecipitation and fluorescence microscopy analysis.
  
  
  RESULTS
  Curcumin treatment dramatically ameliorated metabolic parameters, renal function, morphological parameters in diabetic rats. We found that HG treatment led to significant down-regulation of p-cadherin and synaptopodin, as well as remarkable up-regulation of α-SMA and FSP-1 in vivo and in vitro. Furthermore, curcumin inhibited HG-induced caveolin-1 (cav-1) Tyr(14) phosphorylation associating with the suppression of stabilization of cav-1 and β-catenin.
  
  
  CONCLUSIONS
  In summary, these findings suggest that curcumin prevents EMT of podocytes, proteinuria, and kidney injury in DN by suppressing the phosphorylation of cav-1, and increasing stabilization of cav-1 and β-catenin.
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China.
authors.forename: Li-na
authors.initials: LN
authors.lastname: Sun
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China.
authors.forename: Zhi-xin
authors.initials: ZX
authors.lastname: Chen
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China.
authors.forename: Xiang-chun
authors.initials: XC
authors.lastname: Liu
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China.
authors.forename: Hai-ying
authors.initials: HY
authors.lastname: Liu
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China. Electronic address: guangj@sdu.edu.cn.
authors.forename: Guang-ju
authors.initials: GJ
authors.lastname: Guan
authors.affiliation: Nephrology Research Institute of Shandong University, The Second Hospital of Shandong University, Shandong University, Jinan, Shandong, China. Electronic address: gangliu@sdu.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
mesh_terms: D000818:Animals; D051242:Caveolin 1 / Q000502:physiology*; D002478:Cells, Cultured; D003474:Curcumin / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D051242:Caveolin 1; D003474:Curcumin
keywords: Caveolin-1; Diabetic nephropathy; Epithelial-to-mesenchymal transition; β-catenin