Interleukin-17 plays a role in pulp inflammation partly by WNT5A protein induction.

OBJECTIVE

Our study aimed to investigate the role of interleukin (IL)-17 in dental pulp inflammation and the relationship between WNT5A and IL-17.

METHODS

Immunohistochemical staining was used to detect the expression of tumor necrosis factor-α (TNF-α), WNT5A and IL-17 in pulp tissues. Anti-IL-17 neutralizing antibody was used in rat pulpitis model and to study the role of IL-17 in pulpitis. TNF-α, WNT5A or IL-17 recombinant protein were used to treat human dental pulp cells. RT-PCR, Western blot, and Enzyme linked immunosorbent assay were used to detect the expression of mRNA and protein. Transwell assay was used to measure the migration of THP-1 cells, which is a human monocytic cell line.

RESULTS

IL-17 and WNT5A are co-expressed in TNF-α high-expressed region in human and rat pulpitis tissue. IL-17 mainly contributes to its positive regulatory role in inflammation through up regulate cytokines and mediated macrophages migration. Anti-IL-17 neutralizing antibody can suppress the inflammatory cell infiltration and TNF-α expression in dental pulpitis. TNF-α promotes the expression of IL-17 partly through WNT5A and WNT5A regulates IL-17 expression by mitogen-activated protein kinase (MAPK)-(P38 and ERK) pathway.

CONCLUSIONS

IL-17 acts as an inflammatory mediator in dental pulp inflammation. The expression of IL-17 can be partially regulated by WNT5A.