USP16 drives psoriasis progression by deubiquitinating and stabilizing NLRP3 in keratinocytes.

Psoriasis is a chronic inflammatory dermatosis characterized by pathological keratinocyte hyperproliferation and dysregulated immune activation. While ubiquitin-specific peptidase 16 (USP16) has been implicated in modulating multiple cellular signaling pathways, its functional role in psoriatic pathogenesis remains poorly understood. Our investigation revealed pronounced upregulation of USP16 expression in psoriatic epidermis compared with normal controls. Keratinocyte-specific USP16 knockdown demonstrated remarkable therapeutic efficacy, significantly ameliorating characteristic psoriatic phenotypes including epidermal hyperplasia and inflammatory infiltration. RNA-seq analysis showed that USP16 has substantial effects on cell cycle transition and keratinocytes proliferation. Through KEGG analysis, it was found that USP16 primarily regulates the NLRP3 signaling pathway, leading to enhanced cell proliferation and inflammation. Mechanically, USP16 directly binds to the NLRP3 protein to eliminate K48 ubiquitination modification, enhancing the stability of the NLRP3 protein, activating inflammasome activity. Further studies showed that the therapeutic effects of reducing USP16 on psoriasis progression were counteracted by an NLRP3 activator and keratinocyte-specific NLRP3 overexpression adenovirus. Collectively, these results shed light on how USP16 promotes NLRP3 signaling in keratinocytes, exacerbating psoriasis development. This positive regulation highlights the potential of USP16 as a therapeutic target for psoriasis.