The Molecular Mechanism of Craniofacial Cartilage Deformity Induced by High Glucose in Zebrafish.

Gestational diabetes mellitus (GDM), a prevalent metabolic disorder in pregnancy, induces maternal hyperglycemia and elevates fetal malformation risks, particularly in craniofacial development. To investigate the underlying mechanisms, we employed zebrafish as a model organism due to its conserved skeletal development pathways with humans. Zebrafish embryos were exposed to 3.5% and 4% high glucose (HG) from 10-80 h post-fertilization (hpf). Through comprehensive analyses including Alcian blue staining, confocal microscopy, and molecular assays, we demonstrated that HG exposure caused significant developmental abnormalities including growth retardation, craniofacial cartilage malformations, and impaired cranial neural crest cells (CNCCs) migration and proliferation. Mechanistically, HG induced reactive oxygen species (ROS) accumulation and oxidative stress while downregulating critical CNCCs markers (dlx2 and tfap2a). These molecular alterations correlated with histomorphological defects in pharyngeal arch cartilage, particularly in ceratohyal formation. Our findings establish that glucose disrupts craniofacial development through oxidative stress-mediated CNCCs dysfunction, providing novel mechanistic insights into GDM-associated skeletal abnormalities and potential therapeutic targets.