A bioprinted and scalable model of human tubulo-interstitial kidney fibrosis

Chronic kidney disease (CKD) affects more than 10% of the global population. As kidney function negatively correlates with the presence of interstitial fibrosis, the development of new anti-fibrotic therapies holds promise to stabilize functional decline in CKD patients. The goal of the study was to generate a scalable bioprinted 3-dimensional kidney tubulo-interstitial disease model of kidney fibrosis. We have generated novel human PDGFRβ⁺ pericytes, CD10⁺ epithelial and CD31⁺ endothelial cell lines and compared their transcriptomic signature to their in vivo counterpart using bulk RNA sequencing in comparison to human kidney single cell RNA-sequencing datasets. This comparison indicated that the novel cell lines still expressed kidney cell specific genes and shared many features with their native cell-state. PDGFRβ⁺ pericytes showed three-lineage differentiation capacity and differentiated towards myofibroblasts following TGFβ treatment. We utilized a fibrinogen/gelatin-based hydrogel as bioink and confirmed a good survival rate of all cell types within the bioink after printing. We then combined all three cells in a bioprinted model using separately printed compartments for tubule epithelium, and interstitial endothelium and pericytes. We confirmed that this 3D printed model allows to recapitulate key disease driving epithelial-mesenchymal crosstalk mechanisms of kidney fibrosis since injury of epithelial cells prior to bioprinting resulted in myofibroblast differentiation and fibrosis driven by pericytes after bioprinting. The bioprinted model was also scalable up to a 96-well format.