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Updated: Aug 6, 2026
Accessing the Cytotoxicity and Cell Response to Biomaterials
Published on: July 8, 2021
Interkingdom Endodontic Biofilm Supernatant Induces a Biphasic Inflammatory and Metabolic Transcriptional Response in
Saeed S Alqahtani1, Sumaya Abusrewil2, Othman Baradwan1
1Department of Restorative Dental Sciences, College of Dentistry, Jouf University, Al-Jouf, Saudi Arabia.
Objectives:
To investigate how soluble byproducts derived from a four-species endodontic biofilm model impact the viability, transcriptomic profile, and inflammatory response of human dental pulp stem cells (DPSCs).
Methods:
A sterile-filtered supernatant was extracted from an established interkingdom endodontic biofilm model comprising Streptococcus gordonii, Fusobacterium nucleatum, Porphyromonas gingivalis, and Candida albicans. DPSCs were exposed to the microbial biofilm supernatant (BSN) for 4 and 24 h. Cellular responses were evaluated via MTT, CCK-8, LDH assays, and Annexin V/PI staining. Transcriptomic sequencing was performed to assess gene expression dynamics, with GO and KEGG pathway enrichment analyses. IL6 and IL8 expression was validated by qPCR and ELISA. Data were analyzed using t-tests/ANOVA and RNA-seq differential expression using DESeq. 2 with FDR adjustment.
Results:
BSN significantly suppressed DPSC metabolic activity without inducing apoptosis or necrosis. RNA-seq revealed 723 significantly differentially expressed genes at 4 h and 1667 at 24 h. Early responses were dominated by upregulation of inflammatory mediators, with enrichment of TNF, NF-κB, and JAK-STAT signaling pathways. At 24 h, the expression profile shifted toward redox regulation and metabolic suppression, including downregulation of glycolytic and purine metabolism pathways. IL6 and IL8 expression was markedly increased at both transcript and protein levels.
Conclusions:
Soluble factors produced by a biofilm model representative of deep caries and carious pulp exposures induce a time-dependent transcriptional response in DPSCs. This response is characterized by a biphasic pattern of early immune activation followed by later transcriptional metabolic adaptation. These findings highlight the capacity of soluble biofilm-derived products associated with deep caries to modulate DPSC immune-metabolic signaling. They further emphasize the importance of vital pulp therapy strategies that not only target microorganisms but also account for their secreted byproducts.
