TRPV1 mediates mitochondrial dysfunction in hyperthermia-induced ameloblast mineralization defects

Enamel hypomineralization is a prevalent developmental dental defect associated with several early-life risk factors, including hyperthermia. However, the cellular mechanisms linking hyperthermia to impaired enamel mineralization remain unclear. This study investigated the potential role of transient receptor potential vanilloid 1 (TRPV1) in hyperthermia-associated ameloblast dysfunction.

Using a mouse ameloblast-lineage cell (ALC) model, we performed quantitative real-time PCR (qRT-PCR), alkaline phosphatase (ALP) staining, Alizarin Red S (ARS) staining, RNA sequencing, immunohistochemistry, Western blotting, molecular intervention experiments, intracellular and mitochondrial calcium imaging, reactive oxygen species measurements, and mitochondrial functional assays.

RNA sequencing and immunohistochemistry identified TRPV1 as a candidate heat-responsive channel expressed in ameloblasts. Hyperthermia was associated with reduced mineralization-related markers, increased intracellular and mitochondrial Ca²⁺ signals and reactive oxygen species levels, decreased mitochondrial membrane potential, and impaired ATP content and NAD⁺/NADH ratio. Pharmacological inhibition and genetic suppression of TRPV1 partially alleviated these hyperthermia-associated alterations.

These findings support the involvement of TRPV1 in hyperthermia-associated calcium dysregulation, mitochondrial dysfunction, and impaired mineralization-related responses in cultured ALCs. The results provide a testable framework for further in vivo investigation.