Schuster G S, Erbland J F, Lefebvre C A, Caughman G B, Knoernschild K L
Department of Oral Biology, Medical College of Georgia, Augusta 30912-1126, USA.
J Biomater Sci Polym Ed. 1997;8(5):363-75. doi: 10.1163/156856297x00155.
Methacrylates can affect cell functions by surfactant-like effects or by altering cell lipid composition. Dimethylaminoethyl methacrylate (DMAEMA), an activator widely used in visible-light polymerized dental resins has been shown to elute readily into aqueous environments. The current study examined the metabolism of this material by oral epithelial cells (HCP) and its subsequent effects on cell lipids. Cells were plated in culture medium, then exposed to DMAEMA in the presence of 14C-acetate, a precursor which labeled the cell lipids. Other cultures were prelabeled with radioisotope, then exposed to DMAEMA. After incubation, the cell lipids were extracted and separated by TLC. Radioactive lipids were located and quantitated. Exposure of the cells to DMAEMA resulted in decreased synthesis of cholesterol with a concomitant increase in sterol precursors. Cholesterol esters and triacylglycerides also increased. Among the polar lipids, phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) decreased in response to DMAEMA. However, dimethylphosphatidyl ethanolamine (DMPE), a precursor of PC not detectable in control cultures, accumulated to a significant extent in cells exposed to DMAEMA. Furthermore, changes in PC and DMPE levels persisted in the cells for at least 48 h after removal of the DMAEMA. The results indicate that DMAEMA produces alterations in the relative amounts of several cellular neutral and polar lipids. Such alterations, especially of the normal phospholipid composition, along with an alteration in cellular cholesterol, could result in altered membrane-associated cell functions.
甲基丙烯酸酯可通过类似表面活性剂的作用或改变细胞脂质组成来影响细胞功能。甲基丙烯酸二甲氨基乙酯（DMAEMA）是一种广泛用于可见光聚合牙科树脂的活化剂，已被证明很容易洗脱到水性环境中。本研究检测了这种物质在口腔上皮细胞（HCP）中的代谢及其对细胞脂质的后续影响。将细胞接种于培养基中，然后在14C-乙酸盐（一种标记细胞脂质的前体）存在的情况下暴露于DMAEMA。其他培养物先用放射性同位素预标记，然后暴露于DMAEMA。孵育后，提取细胞脂质并通过薄层层析进行分离。定位并定量放射性脂质。细胞暴露于DMAEMA导致胆固醇合成减少，同时固醇前体增加。胆固醇酯和甘油三酯也增加。在极性脂质中，磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE）对DMAEMA的反应减少。然而，在对照培养物中未检测到的PC前体二甲基磷脂酰乙醇胺（DMPE）在暴露于DMAEMA的细胞中大量积累。此外，在去除DMAEMA后，细胞中PC和DMPE水平的变化至少持续48小时。结果表明，DMAEMA会导致几种细胞中性和极性脂质的相对含量发生改变。这种改变，尤其是正常磷脂组成的改变，以及细胞胆固醇的改变，可能导致与膜相关的细胞功能改变。
