title: Epidermal growth factor and transforming growth factor-beta1 enhance HK-2 cell migration through a synergistic increase of matrix metalloproteinase and sustained activation of ERK signaling pathway.
abstract: Epidermal growth factor (EGF) and transforming growth factor-beta1 (TGF-beta1), upregulated in renal diseases, have a combinational effect on epithelial-mesenchymal transformation (EMT) of renal proximal tubular cells. The aim of this study was to examine the mechanism regarding the combinational effect of EGF and TGF-beta1 on cell migration following EMT. The results demonstrated that EGF (10 ng/ml) and TGF-beta1 (3 ng/ml) synergistically increased cell migration, accompanied by an increase in matrix metalloproteinase-9 (MMP-9) gene expression, production and activity. Inhibition of MMP-9 production and activity by an MMP-2/MMP-9-specific inhibitor blocked the synergistic effect of EGF and TGF-beta1 on cell migration. The kinetic profile of extracellular signal-regulated kinase (ERK) signals demonstrated that ERK1/2 activation was rapidly and strongly induced by EGF but delayed and less marked by TGF-beta1 stimulation. In contrast, co-administration of EGF and TGF-beta1 caused an early pronounced and persistent ERK1/2 activation. Inhibition of the ERK1/2 activity by PD98059 abrogated the synergistic effect of EGF and TGF-beta1 on cell migration, MMP-9 production and activity, indicating that EGF and TGF-beta1 converged at the ERK signaling pathway to mediate cell migration. This study demonstrates that EGF and TGF-beta1 synergistically stimulate proximal tubular cell migration through the increased MMP-9 function and enhanced ERK1/2 activation.
authors.affiliation: Kidney Institute, Department of Nephrology, Chang Gung Memorial Hospital, Taipei, Taiwan. dryctian@adm.cgmh.org.tw
authors.forename: Ya-Chung
authors.initials: YC
authors.lastname: Tian
authors.forename: Yung-Chang
authors.initials: YC
authors.lastname: Chen
authors.forename: Chiz-Tzung
authors.initials: CT
authors.lastname: Chang
authors.forename: Cheng-Chieh
authors.initials: CC
authors.lastname: Hung
authors.forename: Mai-Szu
authors.initials: MS
authors.lastname: Wu
authors.forename: Aled
authors.initials: A
authors.lastname: Phillips
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Yang
mesh_terms: D002460:Cell Line; D002465:Cell Movement; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D053773:Transforming Growth Factor beta1; D004815:Epidermal Growth Factor; D048049:Extracellular Signal-Regulated MAP Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9