title: Impact and significance of EGCG on Smad, ERK, and β-catenin pathways in transdifferentiation of renal tubular epithelial cells.
abstract: We investigated the impact and signal transduction mechanisms of epigallocatechin-3-gallate (EGCG) on transdiffer-entiation of renal tubular epithelial cells. Rat renal tubular epithelial cells (NRK-52E) were randomly divided into a normal control group, transforming growth factor (TGF)-b1-induced group (10 ng/mL), and intervention groups with 200 mg/L EGCG + 10 ng/mL TGF-b1 and 400 mg/L EGCG + 10 ng/mL TGF-b1. Tested cells were collected after 48 h. Levels of a-smooth muscle actin (α-SMA) and cytokeratin-18 were detected using immunohistochemical methods. Western blotting was used to detect cytoplasmic Pi-extracellular receptor kinase 1/2 (ERK1/2), Pi-Smad3 protein, and nuclear b-catenin protein. mRNA expression of ERK2, Smad3, and β-catenin was measured by reverse transcription-polymerase chain reaction. After induction by TGF-b1, cytokeratin-18 expression in the renal tubular epithelial cells decreased and a-SMA expression appeared. mRNA expression of cytoplasmic Pi-Smad3 and Pi-ERK1/2, Smad3, ERK2, and b-catenin protein expression increased, while β-catenin mRNA decreased. These changes were reduced after intervention by EGCG. EGCG may be helpful for maintaining the renal tubular epithelial cell phenotype and reducing the degree of TGF-b1- induced cell transdifferentiation, which may be related to the signal transduction pathway of ERK, Smad3, and β-catenin.
authors: Department of Pediatric Nephrology and Rheumatology, Shengjing Hospital of China Medical University, Shenyang, China.
authors: C G
authors: CG
authors: Zhao
authors: Department of Pediatric Internal Medicine, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
authors: P
authors: P
authors: Zhou
authors: Department of Pediatric Nephrology and Rheumatology, Shengjing Hospital of China Medical University, Shenyang, China gczpcn@163.com.
authors: Y B
authors: YB
authors: Wu
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002460:Cell Line; D004847:Epithelial Cells / Q000187:drug effects*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D007684:Kidney Tubules / Q000187:drug effects*; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects*; D051900:Smad3 Protein / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: C495268:Ctnnb1 protein, rat; D020011:Protective Agents; D051900:Smad3 Protein; C497787:Smad3 protein, rat; D051176:beta Catenin; D002392:Catechin; C045651:epigallocatechin gallate; D048049:Extracellular Signal-Regulated MAP Kinases