
doi: 10.1093/ndt/gfl668
pmid: 17192279
The epithelial sodium channel (ENaC) is a complex, and the alphaENaC subunit has a crucial role in sodium uptake induced by aldosterone in the distal nephron. Although experimental animal models of diabetes have demonstrated up-regulation of alphaENaC expression in renal cortical collecting duct (CCD) cells, the molecular mechanism remains unclear. Advanced glycation end products (AGEs) are by-products of long-term hyperglycaemia and comprise a significant pathogenic factor in diabetic nephropathy. We hypothesize that AGEs play a role in regulating alphaENaC gene expression.Mouse CCD cells (mpkCCDcl(4)) were cultured with AGE to determine the effects of AGE on alphaENaC expression and sodium uptake. Gene expressions of ENaC were measured by real-time PCR and sodium uptake was measured with fluorescent dye as a sodium indicator (SBFI-AM). This study analysed mitogen-activated protein kinases signalling pathways by western blotting. Cells co-transfected with plasmids of the alphaENaC promoter carrying a luciferase reporter and plasmids expressing wild-type or mutant serum- and glucocorticoid-induced kinase 1 (Sgk1) mRNA were stimulated with AGE to identify the signalling pathway.The AGEs, stimulated in a time- and dose-dependent manner, enhanced alphaENaC mRNA expression and sodium uptake in mpkCCDcl(4) cells. The AGEs also significantly stimulated Sgk1 mRNA and Sgk1 activity in a time- and dose-dependent manner. Co-transfected with plasmid expressing mutant Sgk1 significantly limited stimulated alphaENaC promoter-driven luciferase activity by AGEs in mpkCCDcl(4) cells.Experimental results indicate that AGEs induced alphaENaC expression and increased sodium uptake in renal CCD cells. The mechanism through which AGEs activate alphaENaC expression may be via activation of Sgk1 in mpkCCDcl(4) cells.
Glycation End Products, Advanced, Protein Synthesis Inhibitors, Blotting, Western, Phosphotransferases, Mice, Transgenic, Protein Serine-Threonine Kinases, Immediate-Early Proteins, Disease Models, Animal, Mice, Dactinomycin, Animals, Diabetic Nephropathies, RNA, Messenger, Cycloheximide, Kidney Tubules, Collecting, Epithelial Sodium Channels, Promoter Regions, Genetic, Cells, Cultured, Nucleic Acid Synthesis Inhibitors, Plasmids
Glycation End Products, Advanced, Protein Synthesis Inhibitors, Blotting, Western, Phosphotransferases, Mice, Transgenic, Protein Serine-Threonine Kinases, Immediate-Early Proteins, Disease Models, Animal, Mice, Dactinomycin, Animals, Diabetic Nephropathies, RNA, Messenger, Cycloheximide, Kidney Tubules, Collecting, Epithelial Sodium Channels, Promoter Regions, Genetic, Cells, Cultured, Nucleic Acid Synthesis Inhibitors, Plasmids
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 23 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
