Vitamin D metabolism in human kidney organoids

The exciting developments in kidney organoid research have led to improved protocols for the generation of kidney organoids and a better understanding of the complex mechanisms involved in kidney organoid development [1, 2]. Currently the field is moving towards applying the functional potential of kidney organoids either in in vitro or in vivo models [1, 3–5]. For example, LTL+ proximal tubules in kidney organoids demonstrate receptor-mediated endocytosis [3, 5, 6]. However, kidney organoids not only demonstrate the kidney functions of glomerular filtration and tubular reabsorption, the kidneys also play an essential role in the production of hormones to regulate blood pressure (renin), oxygen transport (erythropoietin) and bone metabolism (vitamin D) [7]. We recently demonstrated that the hormone renin is secreted by stromal cells within kidney organoids and that its release can be modulated by external stimuli [...