Department of Periodontology, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
J Inflamm (Lond). 2010 Sep 15;7:48. doi: 10.1186/1476-9255-7-48.
Phenytoin (PHT) has been reported to induce gingival (gum) overgrowth (GO) in approximately 50% of patients taking this medication. While most studies have focused on the effects of PHT on the fibroblast in the pathophysiology underlying GO, few studies have investigated the potential regulatory role of macrophages in extracellular matrix (ECM) turnover and secretion of proinflammatory mediators. The aim of this study was to evaluate the effects of PHT and its metabolite, 5-(p-hydroxyphenyl-), 5-phenylhydantoin (HPPH) on LPS-elicited MMP, TIMP, TNF-α and IL-6 levels in macrophages.
Human primary monocyte-derived macrophages (n = 6 independent donors) were pretreated with 15-50 μg/mL PHT-Na+ or 15-50 μg/mL HPPH for 1 hour. Cells were then challenged with 100 ng/ml purified LPS from the periodontal pathogen, Aggregatibacter actinomycetemcomitans. Supernatants were collected after 24 hours and levels of MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, TIMP-1, TIMP-2, TIMP-3, TIMP-4, TNF-α and IL-6 determined by multiplex analysis or enzyme-linked immunoadsorbent assay.
A dose-dependent inhibition of MMP-1, MMP-3, MMP-9, TIMP-1 but not MMP-2 was noted in culture supernatants pretreated with PHT or HPPH prior to LPS challenge. MMP-12, TIMP-2, TIMP-3 and TIMP-2 were not detected in culture supernatants. High concentrations of PHT but not HPPH, blunted LPS-induced TNF-α production although neither significantly affected IL-6 levels.
The ability of macrophages to mediate turnover of ECM via the production of metalloproteinases is compromised not only by PHT, but its metabolite, HPPH in a dose-dependent fashion. Further, the preferential dysregulation of macrophage-derived TNF-α but not IL-6 in response to bacterial challenge may provide an inflammatory environment facilitating collagen accumulation without the counteracting production of MMPs.
据报道，苯妥英（PHT）在约 50%服用此药的患者中会引起牙龈（牙床）过度生长（GO）。虽然大多数研究都集中在 PHT 对 GO 病理生理学中成纤维细胞的影响上，但很少有研究调查巨噬细胞在细胞外基质（ECM）代谢和促炎介质分泌中的潜在调节作用。本研究旨在评估 PHT 及其代谢产物 5-（对羟苯基）-5-苯基乙内酰脲（HPPH）对 LPS 诱导的 MMP、TIMP、TNF-α 和 IL-6 水平在巨噬细胞中的作用。
用 15-50μg/mL PHT-Na+或 15-50μg/mL HPPH 预处理人原代单核细胞衍生的巨噬细胞（n = 6 个独立供体）1 小时。然后用牙周病病原体伴放线放线杆菌的 100ng/ml 纯化 LPS 刺激细胞。24 小时后收集上清液，并通过多重分析或酶联免疫吸附试验测定 MMP-1、MMP-2、MMP-3、MMP-9、MMP-12、TIMP-1、TIMP-2、TIMP-3、TIMP-4、TNF-α 和 IL-6 的水平。
在 LPS 刺激前用 PHT 或 HPPH 预处理的培养上清液中，观察到 MMP-1、MMP-3、MMP-9、TIMP-1 的剂量依赖性抑制，但 MMP-2 则不然。MMP-12、TIMP-2、TIMP-3 和 TIMP-4 均未在培养上清液中检测到。高浓度的 PHT 但不是 HPPH 减弱了 LPS 诱导的 TNF-α 产生，尽管两者均未显著影响 IL-6 水平。
不仅 PHT，其代谢产物 HPPH 也以剂量依赖的方式削弱了巨噬细胞通过产生金属蛋白酶来介导 ECM 代谢的能力。此外，对细菌刺激的反应中，巨噬细胞衍生的 TNF-α而不是 IL-6 的优先失调可能提供了一个有利于胶原积累的炎症环境，而没有 MMP 产生的对抗作用。
