Modelling kidney cystogenesis using human kidney tubuloid cultures

Renal cyst formation, as observed in autosomal dominant polycystic kidney disease (ADPKD), is a life-threatening condition with no effective cure yet. The molecular mechanisms underlying primary cilia dysfunction, which causes cyst formation and disease development, are not well understood. Human kidney tubuloids offer a promising model system to investigate the disease mechanisms of PKD in physiologically relevant 3D structures. However, their inherent cystic morphology poses a challenge in effectively modelling kidney cystogenesis. Therefore, our study aims to refine the culture method of tubuloids and assess the efficacy of these modified cultures in modeling cyst formation and development.

We developed human kidney tubuloid models derived from adult kidney tubular cells using different methods for 3D in-vitro cultures. Tubuloids cultured in suspension or an extracellular matrix scaffold manifested distinctly polarized epithelial structures. Bulk RNA sequencing and immunohistochemistry revealed differential transcriptional profiles, highlighting variations in cellular composition and cellular fate within the kidney epithelium between the two types of tubuloids. Notably, the experimental activation of chronic cAMP signalling promoted cyst formation in vitro, validating the suitability of these tubuloids for studying kidney cystogenesis. Furthermore, we demonstrate that tubuloids are amenable to genetic modification through recombinant adeno-associated virus transduction.

Our study identifies different in-vitro tubuloid cultures as relevant model systems for examining the molecular and cellular changes involved in kidney cystogenesis in humans. These models will enhance our capability to discover novel pathogenetic mechanisms underlying ADPKD and validate candidate drugs for clinical application.