Csgalnact1 Enhances Vascularized Bone Regeneration Via Erk1/2 In Hbmscs

To elucidate the role of CSGalNAcT1, a key enzyme in chondroitin sulfate proteoglycan (CSPG) synthesis, in vasculogenesis and vascularized osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs). hBMSCs were differentiated in endothelial medium (0-14 days) followed by cultured on Matrigel to evaluate the tube formation ability. RNA-seq identified dynamic CSPG-related transcriptomes during endothelial differentiation. CSGalNAcT1 expression, ERK1/2 activation, and endothelial markers were validated via qPCR/western blot. Functional assays (siRNA knockdown, lentiviral overexpression, CCK-8, transwell, Matrigel plug, 3D imaging) evaluated hBMSC proliferation, migration, and microvascular network formation capacities. Vascularized osteogenesis was tested in mouse cranial defect models (Ethics approval: NYKQ-LAEC-2024-011). RNA-seq revealed upregulation of CSPGs and CSGalNAcT1 during endothelial differentiation of hBMSCs. Knockdown of CSGalNAcT1 suppressed hBMSC proliferation, migration, and endothelial differentiation, while overexpression of CSGalNAcT1 activated ERK1/2 pathway, enhanced microvascular density, and accelerated vascularized cranial bone regeneration. CSGalNAcT1 drives vascularized osteogenesis of hBMSCs via ERK1/2, offering a novel therapeutic strategy for craniofacial regeneration. This study highlights the translational potential of CSGalNAcT1-engineered hBMSCs in clinical bone regeneration.