N-(3-oxododecanoyl)-homoserine lactone regulates intracellular calcium of MC3T3 osteoblasts

Pseudomonas aeruginosa (P. aeruginosa) is associated with periapical periodontitis. The lesions are characterized by a disorder in osteoblast metabolism. Quorum sensing molecular N-(3-oxododecanoyl)-homoserine lactone (AHL) is secreted by P. aeruginosa and governs the expression of numerous virulence factors. AHL can trigger intracellular calcium ([Ca²⁺]i) fluctuations in many host cells. However, it is unclear whether AHL can regulate osteoblast metabolism by affecting [Ca²⁺]i changes or its spatial correlation. We explored AHL-induced apoptosis and differentiation in pre-osteoblastic MC3T3-E1 cells and evaluated [Ca²⁺]i mobilization using several extraction methods. The spatial distribution pattern of [Ca²⁺]i among cells was investigated by Moran's I, an index of spatial autocorrelation. We found that 30 μM and 50 μM AHL triggered opposing osteoblast fates. At 50 μM, AHL inhibited osteoblast differentiation by promoting mitochondrial-dependent apoptosis and negatively regulating osteogenic marker genes, including Runx2, Osterix, bone sialoprotein (Bsp), and osteocalcin (OCN). In contrast, prolonged treatment with 30 μM AHL promoted osteoblast differentiation concomitantly with cell apoptosis. The elevation of [Ca²⁺]i levels in osteoblasts treated with 50 μM AHL was spatially autocorrelated, while no such phenomenon was observed in 30 μM AHL-treated osteoblasts. The blocking of cell-to-cell spatial autocorrelation in the osteoblasts provoked by 50 μM AHL significantly inhibited apoptosis and partially restored differentiation. Our observations suggest that AHL affects the fate of osteoblasts (apoptosis and differentiation) by affecting the spatial correlation of [Ca²⁺]i changes. Thus, AHL acts as a double-edged sword for osteoblast function. Please cite this article below if using any data from this dataset. Guo J, Wang Z, Weng Y, Yuan H, Yoshida K, Ikegame M, Uchibe K, Kamioka H, Ochiai K, Okamura H, Qiu L. N-(3-oxododecanoyl)-homoserine lactone regulates osteoblast apoptosis and differentiation by mediating intracellular calcium. Cellular Signalling. 2020 Aug 18:109740. https://doi.org/10.1016/j.cellsig.2020.109740

铜绿假单胞菌（Pseudomonas aeruginosa, P. aeruginosa）与根尖周周炎密切相关，其病变以成骨细胞代谢紊乱为核心特征。群体感应分子N-(3-氧代十二酰基)-高丝氨酸内酯（N-(3-oxododecanoyl)-homoserine lactone, AHL）由铜绿假单胞菌分泌，可调控多种毒力因子的表达。AHL能够触发多种宿主细胞内的钙离子（[Ca²⁺]i）波动，但目前尚不清楚AHL是否可通过影响[Ca²⁺]i变化及其空间相关性来调控成骨细胞代谢。本研究探究了AHL对前成骨细胞MC3T3-E1的凋亡与分化的诱导作用，并通过多种实验方法评估了[Ca²⁺]i的动员情况；同时采用空间自相关指数Moran's I，解析了细胞间[Ca²⁺]i的空间分布模式。研究发现，30 μM与50 μM的AHL可诱导截然相反的成骨细胞命运：50 μM AHL通过促进线粒体依赖性凋亡，并负向调控成骨标志物基因（包括Runx2、Osterix、骨涎蛋白（bone sialoprotein, Bsp）以及骨钙蛋白（osteocalcin, OCN））的表达，从而抑制成骨细胞分化；与之相反，30 μM AHL长期处理可在诱导细胞凋亡的同时，促进成骨细胞分化。经50 μM AHL处理的成骨细胞，其[Ca²⁺]i水平升高呈现空间自相关性，而30 μM AHL处理的成骨细胞未观察到此现象。阻断50 μM AHL诱导的成骨细胞间空间自相关性，可显著抑制细胞凋亡，并部分恢复其分化能力。本研究结果表明，AHL可通过影响[Ca²⁺]i变化的空间相关性来调控成骨细胞的命运（凋亡与分化），因此AHL对成骨细胞功能而言是一把双刃剑。若使用本数据集的任何数据，请引用以下文章：Guo J, Wang Z, Weng Y, Yuan H, Yoshida K, Ikegame M, Uchibe K, Kamioka H, Ochiai K, Okamura H, Qiu L. N-(3-oxododecanoyl)-homoserine lactone regulates osteoblast apoptosis and differentiation by mediating intracellular calcium. Cellular Signalling. 2020 Aug 18:109740. https://doi.org/10.1016/j.cellsig.2020.109740