Genes differentially expression of endoplasmic reticulum stress signaling pathway caused by excess fluoride in osteoblasts / 重庆医学

ABSTRACT

Objective To observe gene different expression of unfolded protein response signaling pathway in human osteoblasts under the excessive fluoride ,and explore the role of endoplasmic reticulum stress in fluorosis .Methods Human osteoblasts were cultured with fluoride ,intervening for 24 h .Cell viability and apoptosis were inspected by MTS assay and flow cytometer respective‐ly .The UPR signaling pathway was examined by real time PCR array ,and protein expressions were detected by Western blot .Re‐sults T he cell survival rates w ere (100 .678 5 ± 2 .830 3 )% ,(105 .393 4 ± 2 .538 4 )% ,(106 .125 7 ± 2 .048 3 )% ,(77 .977 3 ± 2 .544 3)% (P<0 .05) ,(30 .237 7 ± 0 .632 73)% (P<0 .05) treated with sodium fluoride at the concentration 0 ,5 ,10 ,20 ,40 ,80 mg/L respectively .Apoptosis rate inspected by flow cytometer was 4 .8% in 5 mg/L group ,13 .8% in 10 mg/L group ,37 .0% in 20 mg/L group ,58 .9% in 40 mg/L group ,63 .2% in 80 mg/L group (P<0 .05) .Only 1 gene was down regulated and 14 genes were up regulated .Western blot analysis showed BIP ,ATF4 ,CHOP and IRE1 both showed their protein expression gradually up regula‐ted with fluorine dose .XBP1 expression gradually increased in NaF 5-20 mg/L ,and its expression decreased at 40 and 80 mg/L . Conclusion Sodium fluoride can cause osteoblasts endoplasmic reticulum stress pathway through PTEN and IRE1 pathway ,and at high concentrations can cause apoptosis of osteoblast .