# Splice modulation of COL4A5 reinstates collagen IV assembly in an organoid model of Alport syndrome

## TL;DR

This study shows that antisense oligonucleotides can correct gene splicing in kidney organoids from Alport syndrome patients, offering a potential treatment.

## Contribution

The study introduces a therapeutic screening platform using patient-derived kidney organoids for ASO-based treatment of XLAS.

## Key findings

- ASO treatment effectively restores α5(IV) in organoids with splicing variants.
- GBM maturation in organoids is a dynamic process requiring extended culture.
- Multiomics analysis reveals insights into GBM development in XLAS models.

## Abstract

Kidney organoids are an emerging tool for disease modeling, especially genetic diseases. Among these diseases, X-linked Alport syndrome (XLAS) is a hematuric nephropathy affecting the glomerular basement membrane (GBM) secondary to pathogenic variations in the COL4A5 gene encoding the α5 subunit of type IV collagen [α5(IV)]. In patients carrying pathogenic variations affecting splicing, the use of antisense oligonucleotides (ASOs) offers immense therapeutic hope. In this study, we develop a framework combining the use of patient-derived cells and kidney organoids to provide evidence of the therapeutic efficacy of ASOs in XLAS patients. Using multiomics analysis, we describe the development of GBM in WT and mutated human kidney organoids. We show that GBM maturation is a dynamic process, which requires long organoid culture. Then, using semi-automated quantification of α5(IV) at basement membranes in organoids carrying the splicing variants identified in patients, we demonstrate the efficacy of ASO treatment for α5(IV) restoration. These data contribute to our understanding of the development of GBM in kidney organoids and pave the way for a therapeutic screening platform for patients.

Antisense oligonucleotide therapy corrected gene splicing in kidney organoid models of Alport syndrome, advancing ASO-based strategies for treating inherited kidney diseases