title: Effect of TIMP1 transfection on PTEN expression in human kidney proximal tubular cells.
abstract: To explore the role of metalloproteinase-1 (TIMP-1) tissue inhibitor in the mechanisms of kidney aging, we observed the effects of sense and antisense transfection of TIMP-1 and of metalloproteinase (MMP) inhibitors on phosphatase and tensin homolog (PTEN), vascular endothelial growth factor (VEGF), and Flk-1 expression in TIMP-1 transgenic human proximal tubular epithelial cells (HKCs). Transfected HKCs were co-incubated with 100 μM MMP-2 and MMP-9 inhibitor III for 24 h to affect enzyme inhibition. TIMP-1, MMP-2, MMP-9, PTEN, VEGF, and Flk-1 mRNA expression was detected by reverse transcription-polymerase chain reaction. PTEN, VEGF, and Flk-1 protein expression in cells of each experimental group was measured by indirect immunofluorescence. We found that PTEN expression was up-regulated (P < 0.05) in the sense TIMP-1-transfected group (P < 0.05) compared with the non-transfected and empty vector groups, and that expression of VEGF and Flk-1 was down-regulated (P < 0.05). In contrast, the antisense TIMP-1 transgenic group showed the opposite results (P < 0.05). No significant differences in expression of PTEN, VEGF, or Flk-1 were observed among the MMP- 2/MMP-9 inhibitor III, non-transfected, and empty vector groups (P > 0.05). These results suggest that in the progression of renal aging, high expression of TIMP-1 up-regulates PTEN expression through an MMP-independent pathway, and subsequently down-regulates the expression of VEGF and Flk-1, indicating that PTEN and TIMP-1 are involved in the aging-associated impairment of renal angiogenesis. Our study provides a theoretical basis for further exploration of the mechanism underlying TIMP- 1 participation in renal aging progression.
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: J X
authors.initials: JX
authors.lastname: Chen
authors.affiliation: Department of Geriatric Nephrology, General Hospital of PLA, Beijing, China.
authors.forename: G Y
authors.initials: GY
authors.lastname: Cai
authors.affiliation: Department of Geriatric Nephrology, General Hospital of PLA, Beijing, China.
authors.forename: X M
authors.initials: XM
authors.lastname: Chen
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Geriatric Nephrology, General Hospital of PLA, Beijing, China.
authors.forename: Y M
authors.initials: YM
authors.lastname: Peng
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: F Y
authors.initials: FY
authors.lastname: Liu
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Nephrology, the Second Xiangya Hospital of Central South University, Changsha, China.
authors.forename: S Z
authors.initials: SZ
authors.lastname: Shi
mesh_terms: D000375:Aging / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000235:genetics; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis / Q000235:genetics
chemical_list: D012333:RNA, Messenger; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9