Aged glomeruli: a link between PD-1 and podocytes

Abstract

Understanding the loss of kidney function resulting from kidney aging has become an emerging research focus that will facilitate the future development of antisenolytic treatments. In this issue of the JCI, Pippin et al. first identified PD-1 upregulation in the aged mouse podocyte via unbiased RNA-seq analysis. Overexpression of PD-1 in immortalized mouse podocytes induced cell death and a senescence-associated secretory phenotype, suggesting the pathological role of PD-1 upregulation in aged podocytes. Blocking PD-1 signaling via a neutralizing anti-PD-1 antibody reversed the aged phenotype in the aged mice and ameliorated proteinuria in an experimental focal segmental glomerulosclerosis (FSGS) mouse model. These findings highlight the role of PD-1 signaling in kidney aging and its therapeutic potential for human clinical trials.

Figure 1. PD-1 signaling is involved with cellular senescence and loss in the aged or injured mouse podocytes.

Upregulation of PD-1 expression in aged podocytes, or those from mice with FSGS, leads to a series of detrimental effects, such as cell death, increased cellular senescence, and finally, podocyte loss. Conversely, inhibiting PD-1 signaling via a PD-1-specific antibody improves podocyte ultrastructure, function, gene expression, cell density, and lifespan.