Single-nuclear transcriptomics reveals a diversity of proximal tubule cell states in a dynamic response to acute kidney injury.

We performed a mild-to-moderate ischemia reperfusion injury (IRI) to model injury responses reflective of kidney injury in a variety of clinical settings. Single-nuclear RNA-sequencing (snRNA-seq) of genetically labeled injured PTCs at 7-days (“early”) and 28-days (“late”) time points post-IRI identified specific gene and pathway activity in the injury-repair transition. In particular, we identified Vcam1+/Ccl2+ proximal tubule cells at a late injury stage distinguished by marked activation of NF-kB-, TNF- and AP-1-signaling pathways. This population of PTCs showed features of a senescence-associated secretory phenotype but did not exhibit G2/M cell cycle arrest. These pro-inflammatory, pro-fibrotic proximal tubule cells are likely triggers for chronic disease progression.