Basic Study
Effect of HIF1α-KIM1 pathway on extracellular matrix degradation in human tubular epithelial cells under high glucose
Shifeng Sheng, Rong Gou, Juntong Chen, Ruiqiang Wang, Yudong Fang, Lu Yu, Liuwei Wang, Lin Tang
Published 2016-02-15
Cite as Chin J Nephrol, 2016, 32(2): 126-131. DOI: 10.3760/cma.j.issn.1001-7097.2016.02.008
Abstract
ObjectiveTo investigate the effect of hypoxia inducible factor 1α (HIF1α)-kidney injury molecule 1 (KIM1) pathway on extracellular matrix degradation in human tubular epithelial cells under high glucose, and to explore the possible mechanism of this pathway participated in renal interstitial fibrosis of DN.
MethodsThe human tubular epithelial cells (HK2) were cultured in vitro and divided into the following groups: (1)Normal control Group (D-glucose 5.6 mmol/L); (2) Mannitol group (D-glucose 5.6 mmol/L+D-mannitol 24.4 mmol/L); (3) High glucose group (D-glucose 30 mmol/L); (4) Control siRNA group; (5) HIF1α siRNA group; (6) KIM1 siRNA group. The corresponding indexes were measured at 12th, 24th and 36th hours. Western blotting, immunofluorescence and qRT-PCR were used to examine the expression of HIF1α, KIM1, matrix metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinases-1 (TIMP1), fibronectin (FN) and type I collage (COL-I) in protein and mRNA.
ResultsCompared with the control group, the protein and mRNA expression of HIF1α, KIM1, TIMP1, FN and COL-I in the high glucose group were increased in a time-dependent manner (P<0.01), and MMP9 was decreased in time-dependent manner (P<0.01). Compared with the high glucose group, the protein and mRNA expression of HIF1α, KIM1, TIMP1, FN and COL-I in HIF1α siRNA group was decreased (P<0.01), and MMP9 was increased (P<0.01); However, the protein and mRNA expressions of KIM1, TIMP1, FN and COL-I in KIM1 siRNA group was decreased (P<0.01), MMP9 was increased (P<0.01), and the change of HIF1α was of no significance.
ConclusionsDown-regulation of HIF1α can significantly inhibit the expression of KIM1 in HK2 and decrease the expression of extracellular matrix, and down-regulation of KIM1 can also decrease the extracellular matrix under high glucose, which suggests that HIF1α may regulate the expression of KIM1 in human tubular epithelial cells under high glucose condition, and this pathway may participate in renal interstitial fibrosis of DN.
Key words:
Diabetic nephropathies; Extracellular matrix; Hypoxia inducible factor 1, alpha subunit; Kidney injury molecule 1
Contributor Information
Shifeng Sheng
Department of Nephrology, Nephrology Research Institute of Zhengzhou University Institute of Clinical Medicine, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
Rong Gou
Juntong Chen
Ruiqiang Wang
Yudong Fang
Lu Yu
Liuwei Wang
Lin Tang