NeuroD Expression in Podocytes and Interrelationships with Nephrin at Both Nuclear and Cytoplasmic Sites

Cellular Physiology and Biochemistry

Silvia Armelloni¹ 

关键词: Neurod;    Podocytes;    Adriamycin nephropaty;    Nephrin;    Cytoskeleton;    Transcription factor;    Actin;   

DOI  :  10.1159/000488818

学科分类：分子生物学，细胞生物学和基因

来源: S Karger AG

【 摘 要 】

Background/Aims The research of genes implicated in kidney glomerular function, eliciting cell fate program, is always at the forefront in nephrological studies. Several neurological molecules have been recently the object of study not only for their involvement in the central nervous system differentiation but also for their importance in the functionality of other organs and for mature phenotype, as in kidney. NeuroD, in CNS, is related to two functional roles, the early survival and the differentiation. The aim of our study was to ascertain the presence of NeuroD transcription factor in glomeruli and to understand which targets and mechanisms NeuroD controls. Methods We used immunofluorescence (IF) studies on both human and mice renal tissues and on cultured podocytes to describe NeuroD distribution; then we investigated NeuroD binding to the nephrin promoter region in cultured podocytes by chromatin-immuno-precipitation (ChIP) assay. The overexpression of NeuroD in podocytes was used to establish first its role in nephrin synthesis, evaluated by real-time quantitative (RTq) PCR and western-blot (WB) and successively to determine the recovery of cell morphology after adriamycin injury, measuring foot processes length. Results We identified NeuroD transcription factor in glomeruli, in the same cells positive for WT1 and synaptopodin, namely podocytes; subsequently we observed a differentiation dependent NeuroD distribution in cultured podocytes, and a consistent link of NeuroD with the Nephrin promoter leading to the regulation of Nephrin translation and transcription. Our data also describes NeuroD expression in cytoplasm as phosphoprotein linked to nephrin and actinin4. Preliminary experiments seem to indicate NeuroD involved in dynamics of cell shape regulation after adriamycin injury. Conclusion we propose that NeuroD possess in podocytes a dual ability acting in the nucleus as a transcription factor and in cytoplasm stabilizing cell shape.

【 授权许可】

CC BY-NC-ND