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Objective To investigate the effect and mechanism of cysteine-rich protein 61 (Cyr61) on oxidative stress in human kidney tubular epithelial cell line after anoxia.Methods Human kidney tubular epithelial cell line (HK-2 cells) were divided into 5 groups:control group,Cyr61 group,MAPK inhibitor group (Cyr61 +PD98059),p38 inhibitor group (Cyr61 +SB203580) and PI3K inhibitor group (Cyr61+Wortmannin).Each group was pretreated for 12 h and then injured by anoxia.The cell viability was determined by MTT assay and the apoptosis rate of HK-2 cells was determined by flow-cytometry.The cellular ROS level was measured by spectro-fluorometry.The cellular superoxide dismutase (SOD) and catalase (CAT) were measured by nephelometry test.The expression of Nrf2 in HK-2 cells was detected by Western blotting.Results Anoxia enhanced the expression of ROS and Nrf2,decreased the expression of SOD and CAT significantly,meanwhile decreased HK-2 viability and increased HK-2 apoptosis (all P ＜ 0.05).Cyr61 increased the expression of p-Akt,Nrf2,SOD and CAT in HK-2,and decreased the expression of ROS,at the same time increased HK-2 viability and decreased HK-2 apoptosis (all P ＜ 0.05).Wortmannin inhibited the expression of p-Akt,Nrf2,SOD and CAT,meanwhile decreased HK-2 viability and increased HK-2 apoptosis (P ＜ 0.05).PD98059 and SB203580 had no affect on HK-2 compared to Cyr61 group (P＞0.05).Conclusions Cyr61 promotes the expression of Nrf2 through PI3K pathway in HK-2,which enhances the expression of SOD and CAT,and decreases the expression of ROS.Cyr61 exhibits protective effects on HK-2 cells injured by oxidative stress after anoxia.
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Objective To investigate the effect of cysteine-rich protein 61 (Cyr61) on proliferation and cell cycle in human renal tubular epithelial cells (HK-2).Methods Cyr61 cDNA was cloned into pEGFP-N2,then HK-2 cells were transfected with the recombinant plasmid pEGFP-N2-Cyr61 by Lipofectamine.The cell proliferation was measured by MTT.The expression level of Cyr61,p-FAK and cyclin dependent cyclin-dependent kinase 2 (CDK2) protein were detected by Western blotting.The cell cycle and cell apoptosis were analyzed by flow cytometry.Results The recombinant plasmid pEGFP-N,-Cyr61 could be transfected into HK-2 efficiently.After transfection,the proliferative activity was significantly increased,the proportion of HK-2 cells in G1 phase decreased and in S-phase increased significantly,the level of cell apoptosis decreased markedly (all P ＜ 0.01).The expressions of Cyr61,p-FAK and CDK2 in Cyr61-transfected group were all amplified significantly (all P ＜ 0.01).Conclusions Cyr61 protein over-expressed in HK-2 cells can increase CDK2 expression throngh FAK pathway,resulting in the promotion of HK-2 cells entering into S phase,cell proliferation and the reduction of cell apoptosis.
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Objective To prepare and identify monoclonal antibody against LRR-WSC domain of polycystin-1 and to investigate the distribution of polycystin-1 in kidney tissues and kidney cell lines. Methods BALB/c mice were immunized with fusion protein PC1-e of polycystin-1 LRR-WSC domain. The splenocytes were fused with myeloma cells by PEG 4000 and the hybridomas were selected in HAT medium. The hybridoma clones secreting antibodies against polycystin-1 LRR-WSC domain were detected by enzyme-linked immunosorbent assay ( ELISA) and cloned by limiting dilution. The specificity of anti-polycystin-1 LRR-WSC domain monoclonal antibody from hybridoma was verified by ELISA and Western blot. The distribution of polycystin-1 in tissues and cells was detected by immunohistochemical method. Results One cell line of hybridoma secreting monoclonal antibody against polycystin-1 was established. Western blot analysis showed that the monoclonal antibody reacted strongly and specifically to polycystin-1 LRR-WSC domain. Distribution of polycystin-1 in fetal kidney was localized in tubular epithelium. In normal adult kidney tissues, our study showed that polycystin-1 was mainly expressed in the medullary collecting ducts and distal convoluted tubules. Positive staining was also found in the majority of cyst-lining epithelial ceEs of cystic tissue from autosomal dominant polycystic kidney disease ( ADPKD) patients. Expressions of polycystin-1 were found in either ADPKD cyst-lining epithelia cell line and LLC-PK1, clearly plasma membrane and intracytoplasmic staining of polycystin-1 were observed. Conclusion Specific monoclonal antibody against polycystin-1 LRR-WSC domain were obtained. The antibody is important to researching the mechanism of ADPKD. The distribution of polycystin-1 in kidney tissues and cells show that polycystin-1 was important in tubular elongation and the maintenance of tubular architecture.
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Objective:To investigate characteristic expression of TGF-?1 in human ADPKD and clarify its role in the development and progression of human ADPKD. Methods:Cyst fluid, urinary and plasma TGF-?1 levels were determined by ELISA in 39 ADPKD patients. The results were compared with those of normal subjects and of patients with simple renal cyst. TGF-?1, TGF-?1 receptors types Ⅰ, types Ⅱ, CTGF mRNA and proteins in the kidneys of human ADPKD were examined by in situ hybridization and immunohistochemistry. The relationship of the above fibrosing-associated indicators with the degree of interstitial fibrosis was analyzed. Results:Plasma TGF-?1 level was the highest among body fluids. In ADPKD and simple renal cyst, TGF-?1 levels were significantly higher than those in normal subjects (15.12 ?8.53)?g/L vs (5.41?1.31) ?g/L,P
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Objective To investigate the effect of over-expressed Cyr61 on the expression of extracellular matrix of human renal tubular epithelial cells(HKC), and explore the role of Cyr61 in the pathogenesis and development of autosomal dominant polycystic kidney disease(ADPKD). Methods Cyr61 gene cDNA was amplified by RT-PCR. A recombinant plasmid pcDNA3.1+ Cyr61 was constructed by cloning Cyr61 gene into pcDNA3.1. HKC cells were transfected with wild-type Cyr61 plasmid vector (pcDNA3.1+Cyr61). Then the fusion of Cyr61 gene and expression of its protein were detected by RT-PCR and Western blot. The mRNA expression of Cyr61, collagen Ⅰ, collagen Ⅳ, and laminin were determined in four groups (the untransfected cells, pcDNA3.1 transfected cells, pcDNA3.1+Cyr61 -transfected cells and cyst-lining epithelial cells) by fluorescence quantum PCR. Results The amount of Cyr61 protein in Cyr61-transfected cells and cyst-lining epithelial cells were much greater than the control. The mRNA expression of Cyr61, collagen Ⅰ, collagen Ⅳ and laminin in Cyr61-transfected cells were all amplified significantly, and the level of collagen Ⅳwas much higher than collagen I(P