O‐GlcNAcylation of YAP Enhances Nuclear Translocation to Regulate NRP1‐Mediated Osteogenic Differentiation in MC3T3‐E1 Cells

Abstract Our previous study demonstrated that O-GlcNAc transferase (OGT) promotes osteoblast differentiation in MC3T3‐E1 cells; however, the precise molecular mechanism remains unclear. In this study, we investigated whether OGT regulates osteoblast differentiation through Yes-associated protein (YAP) and neuropilin-1 (NRP1). Using MC3T3-E1 cells, we show that OGT directly O-GlcNAcylates YAP, promoting its nuclear translocation and transcriptional activation of osteogenic regulators RUNX2 and Osterix (OSX). Loss of OGT impaired YAP activity, NRP1 expression, and osteoblast differentiation. Treatment with lysophosphatidic acid (LPA), a YAP activator, restored YAP nuclear accumulation, re-established NRP1 expression, and rescued osteogenic marker expression in OGT-deficient cells. Functional studies further identified NRP1 as a downstream effector of the OGT–YAP axis required for osteogenesis.These findings establish a regulatory pathway in which OGT-mediated O-GlcNAcylation of YAP enhances NRP1-dependent osteogenic differentiation. Moreover, pharmacological activation of YAP by LPA compensates for OGT deficiency, highlighting the OGT–YAP–NRP1 axis as a potential therapeutic target for bone regeneration and osteoporosis.