Background: Although calcineurin inhibitor(CNIs) is the most widely used immunosuppressive agent in kidney transplantation, its nephrotoxicity affects the long-term survival of kidney transplant recipients. To assess the individualized nephrotoxicity of CNIs, we performed the assessment using a method of generating renal tubuloids from the renal tissue of patients.

Methods: Primary human kidney tissue derived from biopsy specimens of living donor kidneys. Mince the tissue into pieces of~1 mm3 size using scalpels and digest pieces of tissue into cell pellets using collagenase. The cell pellets were then transferred into media containing matrigel, B27 supplement, R-spondin,epidermal growth factor, fibroblast growth factor-10, N-acetylcysteine, A83-01and Y-27632. Tubuloids were cultured for several days, re-seeded in 96-well plates, and treated with CNIs(tacrolimus) at doses of 0, 20, 40,or 60μM for 24 hours. Morphological changes, Cell viability and KIM-1 expression were evaluated.

Results: Generation of human tubuloid cultures is identified by immunohistochemical staining for markers expressed in the tubular epithelium, such as paired box 8 protein (PAX8). The 3D structure of the kidney tubuloids and cell viability decreased in dose-dependent manners after treatment with CNIs(tacrolimus). Treatment with CNIs(tacrolimus) increased KIM-1 expression in a dose-dependent manner.

Conclusions: We generated renal tubuloids from patient kidney tissue. This method can evaluate the nephrotoxicity of CNIs in renal transplant patients and provide a possible new way for the personalized medicine of immunosuppressive agent.