HSD17B4 deficiency causes dysregulation of primary cilia and is alleviated by acetyl-CoA.

Primary cilia are dynamic sensory organelles orchestrating key signaling pathways, and disruption of primary ciliogenesis is implicated in a spectrum of genetic disorders. The peroxisomal bifunctional enzyme HSD17B4 is pivotal for peroxisomal β-oxidation and acetyl-CoA synthesis, and its deficiency profoundly impairs peroxisomal metabolism. While patients with HSD17B4 deficiency exhibit ciliopathy-like symptoms due to dysfunctional primary cilia, the molecular connection between HSD17B4 and ciliopathy remains poorly understood. Here, we demonstrate that HSD17B4 deficiency impairs primary ciliogenesis and alters cilia-mediated signaling, suggesting a potential link between peroxisomal metabolism and ciliary function. Notably, elevation of acetyl-CoA rescues ciliary defects via HDAC6-mediated ciliogenesis in HSD17B4-deficient cells. Strikingly, acetate administration restores motor function, enhances primary cilia formation, and preserves the Purkinje layer in Hsd17B4-knockout mice. These findings provide insights into the functional link between HSD17B4 and primary cilia, highlighting acetyl-CoA as a potential therapeutic target for HSD17B4 deficiency and ciliopathy.