AGEs derived from high-sugar diets induce functional impairment of odontogenic stem cells via RAGE-mediated endoplasmic reticulum stress
摘要
This investigation sought to determine whether the formation and progressive buildup of advanced glycation end products (AGEs) within hyperglycemic environments impairs the biological functions of stem cells from human exfoliated deciduous teeth (SHEDs) through a mechanism mediated by the receptor for advanced glycation end products (RAGE), endoplasmic reticulum (ER) stress, and oxidative dysregulation. An in vitro hyperglycemic model was established by culturing SHEDs under high glucose concentrations, AGE exposure, or their combination. Multiple experimental approaches were employed to assess cellular behaviors: proliferative capacity was measured via cell counting kit-8 (CCK-8) assay, migratory ability was evaluated through scratch wound assays, the proportion of apoptotic cells was quantified through annexin V/propidium iodide (PI)-based flow cytometry, while senescence was assessed using senescence-associated β-galactosidase (SA-β-Gal) staining. Critical molecular mediators encompassing RAGE/nuclear factor-κB (NF)-κB signaling components, ER stress biomarkers, oxidative stress parameters, stemness regulators, and osteogenic differentiation markers were quantified through quantitative real-time polymerase chain reaction (qRT-PCR), immunoblotting, immunofluorescence microscopy, and enzyme-linked immunosorbent assay (ELISA) methodologies. Concurrent treatment with high glucose and AGEs substantially suppressed SHED proliferative and migratory capacity while simultaneously enhancing apoptotic cell death and cellular senescence. These functional impairments correlated with elevated RAGE expression, NF-κB pathway engagement, and intensified ER stress responses, as evidenced by augmented GRP78 and CHOP abundance. Oxidative stress parameters were similarly elevated, manifesting as increased reactive oxygen species (ROS) generation and malondialdehyde (MDA) accumulation alongside glutathione (GSH) depletion. The expression of the stemness-associated factors SOX2 and OCT4, together with osteogenic markers RUNX2 and OCN, exhibited marked downregulation. Notably, pharmacological RAGE blockade using FPS-ZM1 successfully reversed these pathological alterations, attenuating ER stress responses, oxidative dysregulation, and functional deterioration triggered by the combined treatment regimen. Our investigation demonstrates that AGEs exacerbate SHED dysfunction under high-glucose conditions by triggering RAGE-dependent ER stress and oxidative stress cascades. This pathological sequence ultimately compromises cellular self-renewal capacity and differentiation potential. Consequently, therapeutic targeting of the RAGE signaling axis represents a promising approach for maintaining dental stem cell functionality and promoting regenerative outcomes in pediatric populations with high-sugar dietary habits.