Pilot spatial transcriptomics of dental pulpitis suggests immune-fibroblast profiling linked to reversibility

Diagnostic protocols in endodontics rely heavily on subjective pain assessments and sensibility testing, which may not reflect the underlying histopathological and molecular state of the dental pulp. This limitation can contribute to discordance between clinical diagnosis (reversible (RP) vs. irreversible (IP) pulpitis) and tissue biology, potentially leading to overtreatment of teeth that might respond to conservative, pulp-preserving approaches. Spatial transcriptomics offers an opportunity to explore the cellular and molecular heterogeneity of inflamed pulp in a spatially resolved manner.

To explore spatial transcriptomic heterogeneity across healthy pulp and clinically diagnosed reversible and irreversible pulpitis samples, and to identify candidate immune-fibroblast features associated with an RP-like versus IP-like molecular profile.

Spatial transcriptomics (Visium-CytAssist-V2) was performed on four human dental pulp tissues (n = 4). Cell deconvolution, differential gene expression, and pathway/module scoring were used to characterize spatial gene-expression patterns in healthy pulp and in clinically diagnosed RP and IP, with attention to coronal regions adjacent to carious lesions.

Despite meeting clinical criteria for symptomatic IP, an IP sample exhibited spatial transcriptomic features more similar to the RP sample, including a comparable immune-to-fibroblast ratio and similar activation patterns of TLR4 and neuroinflammation-related pathways. Across clinically diagnosed IP samples, genes involved in immune signaling, cell migration, and tissue remodeling were differentially expressed. Increased PTN and CXCL14, together with lower expression of ENG (CD105), SELE, COL4A1, CXCL1, and CXCL13, emerged as candidate markers associated with an RP-like molecular profile in this pilot dataset. Overall, spatial patterns suggested that immune-fibroblast composition and interactions may contribute to transcriptomic differences across samples.

In this hypothesis-generating pilot study, spatial transcriptomics highlighted substantial molecular heterogeneity within clinically diagnosed pulpitis and demonstrated that clinical labels may not consistently align with transcriptomic status. Candidate immune-fibroblast features identified here warrant validation in larger cohorts to determine the utility of spatial transcriptomics for refining pulpitis classification and guiding pulp-preserving treatment decisions.