Transcriptomic Analysis of Human Podocytes : Effects of Differentiation and Genotype.

INTRODUCTION

The mechanisms in podocytes that mediate the pathologic effects of the high-risk (HR) variants remain incompletely understood, although various molecular and cellular mechanisms have been proposed. We previously established conditionally immortalized human urine-derived podocyte-like epithelial cell (HUPEC) lines to investigate HR variant-induced podocytopathy.

METHODS

We conducted comprehensive transcriptomic analysis, including mRNA, microRNA (miRNA), and transfer RNA fragments (tRFs), to characterize the transcriptional profiles in undifferentiated and differentiated HUPEC with HR (G1/G2, 2 cell lines) and low-risk (LR) (G0/G0, 2 cell lines) genotypes. We reanalyzed single-cell RNA-seq data from urinary podocytes from focal segmental glomerulosclerosis (FSGS) subjects to characterize the effect of genotypes on podocyte transcriptomes.

RESULTS

Differential expression analysis showed that the ribosomal pathway was one of the most enriched pathways, suggesting that altered function of the translation initiation machinery may contribute to variant-induced podocyte injury. Expression of genes related to the elongation initiation factor 2 pathway was also enriched in the HR urinary podocytes from single-cell RNA-seq, supporting a prior report on the role of this pathway in -associated cell injury. Expression of microRNA and tRFs were analyzed, and the profile of small RNAs differed by both differentiation status and genotype.

CONCLUSION

We have profiled the transcriptomic landscape of human podocytes, including mRNA, miRNA, and tRF, to characterize the effects of differentiation and of different genotypes. The candidate pathways, miRNAs, and tRFs described here expand understanding of -associated podocytopathies.