Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 710004 Shaanxi, China; Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, 710004 Shaanxi, China; Department of Stomatology, Yulin First Hospital, Yuxi Avenue 93, Yulin, 719000 Shaanxi, China.
Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, 710004 Shaanxi, China; Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, 710004 Shaanxi, China; Department of Preventive Dentistry, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.
Arch Oral Biol. 2021 May;125:105093. doi: 10.1016/j.archoralbio.2021.105093. Epub 2021 Feb 24.
The present study aimed to investigated the effect and mechanism of Ca treatment on fluoride in ameloblast-lineage cells (ALCs).
The effects of fluoride and different Ca levels treatment on the proliferative activity, cell apoptosis, cell cycle, intracellular free Ca, were firstly determined. Kallikrein 4 (KLK4), glucose-responsive protein 78 (GRP78), Protein kinase R -like endoplasmic reticulum kinase (PERK), the α subunit of eukaryotic initiation factor 2 (eIF2α), activating transcription factor 4 (ATF4), CCAAT enhancer-binding protein homologous protein (CHOP), were investigated in ALCs.
The proliferative activity was obviously inhibited under concentrations of single fluoride high than 1 mM, and indicated highest proliferation at single 2.5 mM Ca concentration in ALC cells. In addition, we found that single fluoride markedly induced intracellular free Ca increasing, G2/M phase arrest, apoptosis. GRP78 and endoplasmic reticulum stress pathway of PERK/eIF2α/ATF4/CHOP were significantly increased, while the proliferation and KLK4 were markedly reduced in ALCs. Ca additional treatment can obviously reverse the effect of fluoride-induced apoptosis and inhibition of KLK4. The effect of GRP78 and endoplasmic reticulum stress pathway of PERK/eIF2α/ATF4/CHOP were also alleviated under Ca additional treatment in ALCs. More important, the results of 2.5 mmol/L Ca treatment on the proliferation, cell cycle and apoptosis suggest this concentration is relatively better to mediate the intracellular Ca homeostasis in ALCs.
In sum, Ca-supplementation exerts antagonistic the toxic effects on fluoride and this inhibitory effect suggests the potential implications for Ca-supplementation on fluorosis.
本研究旨在探讨钙处理对成釉细胞系（ALCs）中氟化物的作用及机制。
首先测定氟化物和不同钙水平处理对增殖活性、细胞凋亡、细胞周期、细胞内游离钙的影响。研究 KLK4、葡萄糖反应蛋白 78（GRP78）、蛋白激酶 R 样内质网激酶（PERK）、真核起始因子 2 的α亚基（eIF2α）、激活转录因子 4（ATF4）、CCAAT 增强子结合蛋白同源蛋白（CHOP）在 ALCs 中的作用。
在浓度高于 1mM 的单一氟化物作用下，增殖活性明显受到抑制，而在 ALC 细胞中，单一 2.5mM Ca 浓度下表现出最高的增殖活性。此外，我们发现单一氟化物明显诱导细胞内游离钙增加、G2/M 期阻滞和凋亡。GRP78 和 PERK/eIF2α/ATF4/CHOP 内质网应激通路明显增加，而 KLK4 的增殖明显减少。钙的额外处理可以明显逆转氟化物诱导的凋亡和 KLK4 抑制的作用。在钙额外处理下，内质网应激通路 PERK/eIF2α/ATF4/CHOP 的 GRP78 作用也得到缓解。更重要的是，2.5mmol/L Ca 处理对增殖、细胞周期和凋亡的结果表明，该浓度相对较好地调节了 ALCs 细胞内的钙稳态。
总之，钙补充对氟化物的毒性作用具有拮抗作用，这种抑制作用提示钙补充对氟中毒的潜在影响。
