Human kidney-derived tubular organoid, tubuloid, recapitulates cellular senescence, inflammation and fibrosis by repeated-cisplatin treatment

In the pursuit of pathophysiological models for assessing renal drug response, the development of kidney organoids derived from human pluripotent stem cells represents a significant step forward. However, recapitulating aging/senescence-associated pathophysiology remains challenging. Here, we present an innovative approach to generate epithelial-like structures known as "tubuloid" using primary human renal proximal tubular epithelial cells (hRPTECs) cultured from human resected kidneys, as a refined alternative. We evaluated the efficacy of tubuloids using cisplatin treatment. Tubuloids showed highly differentiated structures. Exposure to cisplatin increased {gamma}H2AX, Kidney Injury Molecule-1 (KIM-1) and Cleaved Caspase-3, markers for DNA damage response, epithelial damage and apoptosis respectively. Repeated cisplatin administration resulted in upregulation of the cellular senescence marker p16, p21 and SA-{beta}-Gal. Additionally, increased secretion of inflammatory cytokines, indicating the induction of a senescence-associated secretory phenotype (SASP) were induced Supernatant collected from cisplatin-treated tubuloids induced myofibroblast activation, indicating the onset of renal fibrosis. We successfully established a tubuloid-based model of cisplatin-induced kidney injury using hRPTECs. Tubuloids can replicate cellular senescence, SASP, and fibrosis, which can recapitulate the phenotypes of chronic kidney disease (CKD). Furthermore, tubuloids provide a novel platform for studying the response of renal epithelial cells to toxins and therapeutics and offer innovative strategy for drug screening in a human-based fashion. Translational StatementRecapitulating aging/senescence-associated pathophysiological reaction in kidney organoids remains challenging. Our study reveals that tubuloids could be novel candidate for chronic kidney disease (CKD) model.