Gain-of-function ENL YEATS domain mutations impede nephrogenesis through gene expression control [Spatial Transcriptomics]

Hotspot gain-of-function mutations in the YEATS domain of the histone reader protein ENL have been identified in Wilms’ tumor. To investigate the pathogenic role of these cancer-associated ENL mutations in kidney development and tumorigenesis in vivo, we generated conditional knock-in mouse models mimicking patient-derived ENL YEATS mutations. Mice with heterozygous expression of ENLT mutants in either Six2+ nephrogenic or Foxd1+ stromal lineage exhibit severe yet distinct defects in kidney development, both resulting in neonatal lethality. The Six2-ENLT mutant kidney rudiments display compromised cap mesenchyme, scant proximal tubules and cystic glomeruli, indicative of premature commitment and differentiation blockade during nephrogenesis. Bulk and spatial transcriptomic analyses uncover aberrant activation of Hox genes and genes involved in cell fate commitment, especially the Wnt signaling pathway, in ENLT mutant-expressing nephrogenic cells. In contrast, the Foxd1-ENLT mutant kidneys exhibit expansion in renal capsule and cap mesenchyme, accompanied with dysregulation of stromal genes involved in nephrogenesis and stroma-nephron crosstalk. Collectively, our study sheds lights on how ENL YEATS domain mutations impede nephrogenesis through different pathways in nephrogenic and stromal lineages, paving the way for further investigations into their roles in tumorigenesis. Floxed Enl T mutant alleles were crossed with Cre strains (Foxd1-GC/+ or Six2-TGC tg/+) with or without LSL-tdT Cre reporter allele to get embryonic kidney at E14.5 and E18.5 stage. RNA was extracted from whole kidney or sorted tdT+ cells for sequencing.