RYK is a GPNMB receptor that drives MASH
Article Date: 18 February 2026
DOI / URL: https://doi.org/10.1038/s41586-026-10160-z
Summary
This Nature paper identifies the receptor RYK as a functional binding partner for GPNMB (glycoprotein nonmetastatic melanoma protein B) and shows that GPNMB signalling via RYK drives metabolic dysfunction-associated steatohepatitis (MASH) in preclinical models. The authors combine human cohort/transcriptomic data and multiple mouse diet models (HFHC, AMLN, CDHFD) with genetic ablation and therapeutic interventions (AAV-shRNA, GalNAc-siRNA, neutralising antibodies) to show that blocking GPNMB or its receptor pathway reduces steatosis, inflammation and fibrosis and improves metabolic parameters. RNA-seq data from this study are available at GEO accession GSE260956.
Key Points
- GPNMB is strongly upregulated in MASH patient livers and in multiple mouse diet models of steatohepatitis.
- Whole-body and hepatocyte-specific Gpnmb ablation protects mice from diet-induced steatosis, inflammation and fibrosis.
- The extracellular domain of GPNMB (G‑ECD) is shed; this circulating fragment drives pathogenic signalling in the liver.
- RYK is identified as a receptor required for G‑ECD-driven MASH; engagement activates ERK1/2 signalling in target cells.
- Therapeutic targeting—AAV8-shGpnmb, GalNAc-siRNA against Gpnmb, and a G‑ECD neutralising antibody—all reverse or ameliorate established MASH and improve systemic metabolism in mice.
- Shedding of GPNMB involves ADAM-type proteases and shedding-resistant GPNMB mutants alter pathogenicity, pointing to multiple intervention points.
- Data include robust histology, biochemical endpoints (TG, AST/ALT), gene expression, proteomics and multiple diet-induced disease models, increasing translational relevance.
Content summary
The authors first show that hepatic GPNMB expression is elevated in patient cohorts with MASLD/MASH and in several mouse models fed obesogenic or methionine/choline-deficient diets. Genetic deletion of Gpnmb (systemic and hepatocyte-specific) substantially reduces steatosis, inflammatory markers and fibrosis scores across diets. Mechanistic studies reveal that the ectodomain of GPNMB (G‑ECD) is shed and circulates; G‑ECD drives pro-steatotic and pro-fibrotic programmes when present systemically.
Using unbiased binder screening and cellular assays, the team identifies RYK as a receptor required for G‑ECD effects. G‑ECD–RYK interaction activates ERK1/2 and downstream transcriptional programmes linked to lipogenesis, inflammation and stellate cell activation. Interventions that lower Gpnmb expression or neutralise G‑ECD—AAV-mediated shRNA, GalNAc-conjugated siRNA and a neutralising antibody—ameliorate established disease and improve insulin sensitivity and systemic metabolism in mice. The authors also characterise GPNMB variants and shedding-resistant mutants to map functional domains and protease involvement.
Context and relevance
MASH (previously NASH) has lacked broadly effective disease-modifying drugs. GPNMB has been implicated previously as a biomarker and mediator in metabolic and immune contexts; this study elevates it from biomarker to actionable ligand with an identified receptor (RYK). That RYK is a non-canonical Wnt-related receptor ties these findings into wider Wnt/RYK biology and metabolic regulation. The preclinical therapeutic data (antibody, GalNAc-siRNA, AAV-shRNA) are directly relevant to translational strategies and suggest multiple routes to modulate this axis in liver disease.
Author style: Punchy — this paper is big news for folks tracking new targets in steatohepatitis and liver therapeutics; the data back both target biology and feasible intervention strategies.
Why should I read this?
Short version: if you follow NASH/MASH biology or are hunting new therapeutic targets, this one’s worth your time. The authors didn’t just spot a biomarker — they found the receptor (RYK), showed causality in mice, and tested realistic therapies that actually reverse disease. We read it so you don’t have to — but you’ll want to dig into the methods if you’re thinking translational work or drug programmes.