Work

Base Editing as a Therapeutic Strategy for Autosomal Dominant Tubulointerstitial Kidney Disease caused by Pathogenic UMOD Variants

Year: 2026

Type: preprint

Abstract: Autosomal dominant tubulointerstitial kidney disease caused by pathogenic UMOD variants (ADTKD- UMOD ) is an untreatable monogenic kidney disease in which misfolded uromodulin is retained in the endoplasmic reticulum and exerts a toxic gain-of-function effect. Here we systematically evaluate the full spectrum of base editing strategies targeting the UMOD locus. Base editors corrected a representative missense patient variant, p.Cys170Tyr, with A-to-G conversion efficiencies of up to 83.4%, restoring uromodulin trafficking to the plasma membrane in cell lines and in human 3D kidney tubuloids. Mutation-agnostic inactivation was achieved by four routes: premature stop codon introduction, splice-site disruption, allele-specific stop codon introduction and promoter attenuation. Maximum on-target efficiencies ranged from 44.1% to 71.9%, providing a strategy set applicable across the UMOD allelic spectrum. Endogenous UMOD expression is rarely recapitulated in human cell models, leaving strategies that act on the endogenous gene difficult to assess in patient cells. We therefore established CRISPR activation (CRISPRa) of the endogenous UMOD promoter and confirmed its ability to upregulate UMOD expression in human urine-derived cells. This approach further enabled quantification of endogenous UMOD transcript reduction following base editing in HEK293 cells. These results establish base editing as a versatile approach for ADTKD- UMOD and provide a primary human system for testing interventions targeting endogenous UMOD expression, from nucleic acid-based silencing to small molecules.

Source: bioRxiv (Cold Spring Harbor Laboratory)

DOI: 10.64898/2026.10.15.758759