ABSTRACT
Human proximal tubule epithelial cell line,HK-2 cells,were cultured with various concentrations of insulin for 48 h.Human urate transporter (hUAT) mRNA was detected by realtime quantitative PCR.hUAT mRNA levels were down-regulated by insulin (5,25,125,500 μIU/ml)in a dose-dependent manner (relative expression median were 0.95,0.40,0.24,and 0.23).In vitro,the expression of hUAT mRNA in HK-2 cells is associated with the concentration of insulin.
ABSTRACT
Objective We reported previously that single nucleotide polymorphisms SNP) + 11G ＞ A in intron 3 of the human urate transporter 1 (hURAT1) gene are associated with hyperuncaemia in Han Chinese.The aim of the present study was to evaluate the effect of the variants on hURAT1 function.Methods The wild-type,mutant-type hURAT1 and exon 5-null hURAT1 were constructed,and respectively microinjected into the zebrafish embryo yolks.The subcellular localization of different genotypes of hURAT1 was detected by confocal laser scanning microscope.Results Compared with wild type,the mutant recombinant plasmid transcribed two types of mRNA spliceosome,the wild type and the exon 5-null type.The hURAT1 wild type protein was prominent localized on cell membrane,while the mutant type and exon 5-null hURAT1 proteins were distributed uniform in the cytoplasm but not on the cell membrane.Conclusion The hURAT1 variant + 11 G ＞ A resulted in an alternative splicing of hURAT1 mRNA-exon 5-null type.Its protein product exhibited a different subcellular localization compared with that of wild type.
ABSTRACT
ObjectiveTo analyze the association of human urate transporter 1 ( hURAT1 ) gene promoter single-nucleotide polymorphisms(SNPs) with primary hyperuricemia ( HUA ) in Chinese Han people.MethodsA total of 215 patients with HUA and 323 healthy subjects were chosen to be investigated of SNP of hURAT1 promoter by PCR and sequencing.ResultsFive SNPs were identified,including-454A/T,-434T/C,-382C/T,-87C/T,and + 118G/A.Pairwise linkage disequilibrium analysis displayed a high linkage disequilibrium between the five SNPs ( r2 =0.99).In HUA group,the heterozygous genotypos ( AT,CT,CT,CT,AG ) frequencies were significantly lower than those in control group ( P＜0.05 ).Logistic regression analysis showed that the heterozygosis genotypes ( AT,CT,CT,CT,AG) were protective factors of HUA ( OR 0.68-0.75 ).The minor allele ( T,C,T,T,A ) frequencies for both SNPs were significantly different between two groups ( P =0.022,P =0.038 ).ConclusionThese findings indicate that -454A/T,-434T/C,-382C/T,-87C/T,and + 118G/A SNPs of hURAT1 gene promoter area are associated with HUA in Chinese Han population.
ABSTRACT
Idiopathic renal hypouricemia is a disorder characterized by impaired urate handling in the renal tubules. This disease usually produces no symptoms, but hematuria, uric acid nephrolithiasis or acute renal failure may develop. A defect in the SLC22A12 gene, which encodes the human urate transporter, is the known major cause of this disorder. We describe a 10-month-old boy with idiopathic renal hypouricemia. He was diagnosed with transient pseudohypoaldosteronism at admission, but hypouricemia was accidentally found through follow-up study. By gene analysis, his diagnosis was confirmed to idiopathic renal hypouricemia. In addition, we report a mutation in the human urate transporter 1 (hURAT1) gene identified in his family.