Original Article Transcription of nephrin–Neph3 gene pair is synergistically activated by WT1 and NF-kB and silenced by DNA methylation

Background. Nephrin and Neph3 are homologous mole-cules expressed in the podocyte slit diaphragms that are essential for normal glomerular ultrafiltration. Nephrin and Neph3 genes form a bidirectional gene pair suggesting that they may share key features in their regulation. We investigated if nephrin and Neph3 genes have similar mechanisms in their transcriptional regulation focussing on transcription factor Wilms ’ tumour 1 (WT1) and nuclear factor-jB (NF-jB) and DNA methylation. Methods. Transcriptional regulation of nephrin and Neph3 by WT1 and NF-jB was analysed by overexpression stud-ies, reporter gene assay and chromatin immunoprecipita-tion using A293 cells and cultured podocytes. The interaction between WT1 and NF-jB was studied by co