Abstract: Ｏｂｊｅｃｔｉｖｅ：To elucidate pathophysiology of podocytes for prevention and treatment of podocytopathies by human immortalized podocytes.
Ｍｅｔｈｏｄｏｌｏｇｙ：We compare their gene expression profiles based on single-cell RNA-seq databases and the RNA-seq data generated by ourselves to identify differentially expressed genes.
Ｒｅｓｕｌｔｓ：There are enormous differences of gene expression between immortalized human podocytes and those in vivo(R=0.11,P<2.2×10-16). Particularly, expressions of the genes and markers that are known to be essential for structure and function of podocytes are mostly lost in the human immortalized podocyte cells, including WT1, the master transcription factor that determines podocyte development, differentiation and maturation. We speculate that the marked downregulation of WT1 in the immortalized cells underlies expression loss of majority of podocyte-specific genes. We then express exogenous WT1 in the cells using plasmid transfection, and found expression restoration of some podocyte-specific genes.
Ｃｏｎｃｌｕｓｉｏｎ：The human immortalized podocytes and the podocytes in vivo differ greatly in gene expression, making the former not a reliable tool for in vitro studies. However, exogenous WT1 expression can restore expression of some podocyte specific genes, resulting in cells closer to the podocytes in vivo and more reliable experimental data.

Key words: immortalized podocytes, podocytes in vivo, gene expression