Key Role of Pro-inflammatory Cytokines in the Toxic Effect of Fluoride on Hepa1-6 Cells

• Published in: Biological trace element research Vol. 197; no. 1; pp. 115 - 122
• Main Authors: Zhang, Yan, Zhou, Bian-hua, Tan, Pan-pan, Chen, Yu, Miao, Cheng-yi, Wang, Hong-wei
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2020; Springer Nature B.V
• Subjects: Biochemistry; Biomedical and Life Sciences; Biotechnology; Cell viability; Cytokines; ELISA; Enzyme-linked immunosorbent assay; Exposure; Fluorides; IL-1β; Immunofluorescence; Inflammation; Interleukin 2; Interleukin 6; Life Sciences; Necrosis; Neoplasms; Nutrition; Oncology; Protein expression; Proteins; Secretion; Toxicity; Tumor cells; Tumor necrosis factor-TNF; Tumor necrosis factor-α; IL-2; Fluoride; TNF-α; IL-1β; Hepa1-6; IL-6
• ISSN: 0163-4984; 1559-0720
• DOI: 10.1007/s12011-019-01967-1

The role of pro-inflammatory cytokines in the toxicity of fluoride to tumor cells was investigated by culturing Hepa1-6 cells in medium containing gradient concentrations of fluoride (0, 0.5, 1, 1.5, 2, 3, 4, and 5 mmol/L). The viability of Hepa1-6 cells was detected via MTT assay. Interleukin (IL)-2, IL-6, tumor necrosis factor (TNF)-α, and IL-1β levels in the supernatant were determined via an enzyme-linked immunosorbent assay, and the protein expression levels of these enzymes in Hepa1-6 cells were evaluated by immunofluorescence staining. Results showed that the viability of Hepa1-6 cells remarkably decreases after fluoride exposure, especially at concentration of 3, 4, and 5 mmol/L fluoride. Levels of IL-2, TNF-α, and IL-1β in the supernatant markedly decreased when cells were exposed to fluoride at concentrations of 1 mmol/L or higher. However, levels of TNF-α and IL-1β substantially increased and IL-2 showed no remarkable change when the fluoride concentration was 0.5 mmol/L. The content of IL-6 remarkably increased with increasing fluoride concentrations up to 2 mmol/L, and then markedly decreased at 3, 4, and 5 mmol/L fluoride; the decreasing trend of IL-6 content under high fluoride exposure is consistent with the decrease in Hepa1-6 cell viability observed at the same concentration. The protein expression levels of IL-2, IL-6, TNF-α, and IL-1β were in accordance with their contents in the supernatant. In summary, our study demonstrated that fluoride inhibits Hepa1-6 cell growth and results in disorders in the expression and secretion pro-inflammatory cytokines.