Abstract: Objective To analyze the expression characteristics and related receptors of tumor necrosis factor-alpha (TNF- α) on the regulation of transient receptor potential vanilloid 2 (TRPV2) in human odontoblasts (HODs) -like cells,which would further enrich the study on the physiological functions of TRPV2 ion channels in human dental pulp. Methods Twenty intact and healthy third molars extracted for orthodontic purpose were collected from adults aged between 18 and 25 years in the department of maxillofacial surgery, stomatological hospital of Tianjin Medical University from September 2016 to January 2017. The pulp tissues were obtained, cultured and induced and passaged in the minimum essential medium(MEM). The 4-6 passages of cells were utilized in the subsequent experiments. Immunofluorescence staining was used to detect the expression characteristics of HDDs-like protein dentin sialophospho protern (DSPP) and nestin. The influences of 1 µg/L and 10 µg/L TNF-α on TRPV2 ion channel expression in HODs-like cells were investigated by RT-qPCR, Western blot assay and flow cytometry. Tumor necrosis factor receptor (TNFR)1 antagonist R-7050 was used to treat cells, and analyze its role in the regulation of TRPV2 ion channel by TNF-α. Results Immunofluorescence staining showed positive expressions of DSPP and nestin in HODs-like cells. Results of RT-qPCR and Western blot assay confirmed that 10 µg/L of TNF-α significantly up-regulated the mRNA and protein expression of TRPV2 ion channel compared with that of control group without TNF - α treatment (P＜0.05). Flow cytometry also showed that TNF - α could obviously up-regulate the expression level of TRPV2 protein. Further study confirmed that the increasing expression level of TRPV2 ion channels in human HODs-like cells treated with TNF- α was obviously downregulated after R-7050 treatment compared with that of control group without R-7050 treatment (P＜0.05). Conclusion TNF-α up-regulates TRPV2 ion channel expression level by TNFR1 in HODs-like cells.

Key words: dentin, tumor necrosis factor-alpha, receptors, tumor necrosis factor, receptors, tumor necrosis factor, type Ⅰ, human odontoblast-like cells, transient receptor potential vanilloid 2