The effect of fluoride on the viability of rat ameloblast HAT-7 cells and Ca2 + concentration in the cells / 实用口腔医学杂志

Objective:To evaluate the effect of fluoride on the viability of rat ameloblast HAT-7 cells and calcium concentration in the cells.Methods:HAT-7 cells were exposed to NaF at 0,0.4,0.8,1.6,3.2 and 6.4 mmol/L for 24,48 and 72 h respectively. CCK-8 assay was performed to examine the cells proliferation;the apoptosis rate was determined by flow cytometry;Ca2 +concentration in the cells was detected by laser scanning confocal microscopy.Results:The cell proliferation was increased by NaF at 0.4 mmol/L and 0.8 mmol/L,whereas inhibited at 1.6 mmol/L and above.The effects were in a time-dependent manner.NaF increased apoptosis of the cells and increased Ca2 + concentration in the cells in a concentration-dependent manner.Conclusion:Fluoride at low doses promotes proliferation,at high doses inhibits proliferation of HAT-7 cells.NaF of 1.6 mmol/L or more induces apoptosis of HAT-7 cells and in-duce Ca2 + overloading in the cells.

Excessive fluoride inducing calcium overload and apoptosis of ameloblasts / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effect of excessive fluoride on calcium overload and apoptosis in cultured rat ameloblasts in vitro.</p><p><b>METHODS</b>Logarithmic-phase ameloblasts (HAT-7) were treated with 0, 0.4, 0.8, 1.6, 3.2, and 6.4 mmol · L(-1) sodium fluoride (NaF) solution. Cell activities were detected by using a Cell Counting Kit 8 (CCK-8) assay after 48 h of treatment. The effect of fluoride on cell apoptosis was analyzed by using flow cytometry. Excessive fluoride-induced calcium concentration and calreticulin expression changes in ameloblasts were detected by using laser scanning confocal microscopy, Western blot analysis, and real-time quantitative polymerase chain reaction.</p><p><b>RESULTS</b>NaF inhibited ameloblast activity at 1.6, 3.2, and 6.4 mmol · L(-1) (dose-dependent) after 48 h of induction. The Ca2+ fluorescence intensity of HAT-7 cells incubated with 1.6 and 3.2 mmol · L(-1) NaF was higher than that in the control group. The fluoride-induced early-stage apoptosis of ameloblasts after 48 h of induction and the early-stage apoptosis rate was positively correlated with fluoride concentration. Calreticulin mRNA expression in HAT-7 cells was higher than that in the control group after 48 h of incubation with 0.8, 1.2, and 1.6 mmol · L(-1) NaF.</p><p><b>CONCLUSION</b>Excessive fluoride-induced calcium overload in ameloblasts and further caused endoplasmic reticulum stress-mediated apoptosis.</p>