RIPK3-RNASE1 axis as a potential therapeutic and clinical monitoring target in VEXAS syndrome

Vacuole, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome (VS) is a severe autoinflammatory disease driven by somatic mutations in ubiquitin-like modifier activating enzyme 1 (UBA1), for which disease activity biomarkers and therapeutic targets are needed. We conducted longitudinal deep phenotyping of patients with VS and found that ribonuclease 1 (RNASE1) expression is most strongly correlated with the disease activity score measured by the VEXAS Current Activity Form (VEXASCAF). Single-cell RNA-sequencing showed that RNASE1 was upregulated in VS monocytes. We generated human monocytic cell lines harboring UBA1 mutations (p.Met41Val, p.Met41Leu, and p.Met41Thr). These cells exhibited varying degrees of impaired ubiquitination and subsequent pathological features such as the unfolded protein response, increased pro-inflammatory cytokine production, cell death, and RNASE1 expression, mirroring the genotype-phenotype associations observed in patients with VS. Multi-omics analyses revealed that genotypes linked to greater clinical severity were enriched in pro-inflammatory, interferon, and necroptosis signatures. Notably, functional interrogation demonstrated that inhibition of receptor-interacting protein kinase 3 (RIPK3), a key regulator of necroptosis, markedly suppressed all these pathological features, including the elevated RNASE1 expression. These results identify the RIPK3-RNASE1 axis in VS, highlighting RNASE1 as a potential biomarker and RIPK3 as an attractive therapeutic target.