Department of Restorative Odontology and Endodontics, School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Department of Pharmacology in Dentistry, School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Int J Mol Sci. 2023 Jan 29;24(3):2562. doi: 10.3390/ijms24032562.
High elution and diffusion of 2-hydroxylethyl methacrylate (HEMA) and camphorquinone (CQ) through dentinal tubules may induce pulp injury and postoperative sensitivity. We aimed to investigate the melatonin protective effect in HEMA- and CQ-treated human dental pulp cells (hDPCs) as well as its relevance in a mechanism for postoperative sensitivity in diabetic patients. hDPCs were exposed to HEMA (5 mM) and/or CQ (1 mM) in the absence and presence of melatonin (MEL) (0.1 mM and 1 mM). Heme oxygenase-1 (HMOX1), NADPH oxidase-4 (NOX4), BCL-2-associated X-protein (BAX), B-cell lymphoma-2 (BCL-2) and caspase-3 (CASP3) gene expression levels, and superoxide dismutase (SOD) activity were measured in hDPCs while inducible nitric oxide synthase (iNOS) and melatonin protein expression were measured in human dental pulp as well, by RT-PCR, by ELISA, and spectrophotometrically. Bioinformatic analyses were performed by using the ShinyGO (v.0.75) application. Type 2 diabetic patients showed a higher incidence of postoperative sensitivity and lower melatonin and higher iNOS content in dental pulp tissue compared with non-diabetic patients. Melatonin, when co-added in hDPC culture, reverses HEMA and CQ cytotoxic effects via anti-apoptotic and anti-inflammatory/antioxidant iNOS-related effects. Enrichment analyses showed that genes/proteins, altered by HEMA and CQ and normalized by melatonin, are the most prominently overrepresented in type 2 diabetes mellitus pathways and that they share subcellular localization in different oligomeric protein complexes consisting of anti- and pro-apoptotic regulators. This is the first evidence of the ability of melatonin to counteract iNOS-mediated inflammatory and stress effects in HEMA- and CQ-treated hDPCs, which could be of significance for the modulation of presently observed immediate postoperative sensitivity after composite restoration in type 2 diabetic patients.
高浓度的 2-羟乙基甲基丙烯酸酯（HEMA）和樟脑醌（CQ）通过牙本质小管的洗脱和扩散，可能会引起牙髓损伤和术后敏感。我们旨在研究褪黑素对 HEMA 和 CQ 处理的人牙髓细胞（hDPC）的保护作用，以及其在糖尿病患者术后敏感的机制中的相关性。将 hDPC 暴露于 HEMA（5mM）和/或 CQ（1mM）中，同时存在和不存在褪黑素（MEL）（0.1mM 和 1mM）。在 hDPC 中测量血红素加氧酶-1（HMOX1）、NADPH 氧化酶-4（NOX4）、B 细胞淋巴瘤-2 相关 X 蛋白（BAX）、B 细胞淋巴瘤-2（BCL-2）和半胱天冬酶-3（CASP3）基因表达水平，以及超氧化物歧化酶（SOD）活性，同时测量人牙髓中的诱导型一氧化氮合酶（iNOS）和褪黑素蛋白表达，通过 RT-PCR、ELISA 和分光光度法。通过使用 ShinyGO（v.0.75）应用程序进行生物信息学分析。与非糖尿病患者相比，2 型糖尿病患者的术后敏感发生率更高，牙髓组织中的褪黑素含量更低，iNOS 含量更高。褪黑素在 hDPC 培养中共同添加时，通过抗凋亡和抗炎/抗氧化 iNOS 相关作用逆转 HEMA 和 CQ 的细胞毒性作用。富集分析表明，HEMA 和 CQ 改变并由褪黑素正常化的基因/蛋白在 2 型糖尿病途径中最为突出，并且它们在不同的寡聚蛋白复合物中具有亚细胞定位，这些复合物由抗凋亡和促凋亡调节剂组成。这是褪黑素能够拮抗 HEMA 和 CQ 处理的 hDPC 中 iNOS 介导的炎症和应激作用的第一个证据，这对于调节 2 型糖尿病患者复合修复后目前观察到的即刻术后敏感可能具有重要意义。
