Amelogenin promotes cellular activation of stem cells derived from human exfoliated deciduous teeth through...

Stem cells from human exfoliated deciduous teeth (SHED) represent a minimally invasive source of mesenchymal stem cells for dental tissue regeneration. Although amelogenin, a major enamel matrix protein, is known to enhance the regenerative potential of various dental-derived stem cells, the mechanism-particularly the involvement of the CD63 receptor and extracellular signal-regulated kinase (ERK)1/2 signaling pathway- through which it activates SHED remains unclear. This study aimed to evaluate the effects of amelogenin on cell proliferation and migration in SHED and elucidate the mechanism of signaling via the CD63 receptor.

Primary SHED were isolated from exfoliated deciduous teeth and cultured. Cellular activation by amelogenin (1000 ng/mL) was assessed via migration (scratch assay), proliferation (live-cell imaging and 5-bromo-2'-deoxyuridine incorporation), immunofluorescence for CD63 expression, western blotting, and enzyme-linked immunosorbent assay for ERK1/2 phosphorylation. The functional roles of CD63 and ERK1/2 were analyzed using an anti-CD63 neutralizing antibody and MEK1/2 inhibitor U0126.

Amelogenin significantly enhanced both the migration and proliferation of SHED compared to the controls. Immunostaining demonstrated that amelogenin increased CD63 expression in SHED. Amelogenin also elevated ERK1/2 phosphorylation, and blockade of CD63 or MEK1/2 abrogated amelogenin-induced increases in cell proliferation, DNA synthesis, and ERK1/2 phosphorylation.

Amelogenin promotes the migration and proliferation of SHED through CD63-mediated ERK1/2 signaling, highlighting a promising approach for enhancing cell-based repair of refractory bone defects in dental regenerative medicine.