Enhancement of receptor‐mediated calcium responses by phenytoin through the suppression of calcium excretion in human gingival fibroblasts
Enhancement of receptor‐mediated calcium responses by phenytoin through the suppression of calcium excretion in human gingival fibroblasts
复制标题
苯妥英通过抑制人牙龈成纤维细胞中的钙排泄来增强受体介导的钙反应
DOI：
10.1111/jre.13089
复制
发表时间：
2023
影响因子：
3.5
通讯作者：
Tanimura Akihiko
中科院分区：
文献类型：
--
作者：
Minowa Erika;Hayashi Yoshinobu;Goh Kenji;Ishida Narumi;Kurashige Yoshihito;Nezu Akihiro;Saitoh Masato;Tanimura Akihiko
背景与目的苯妥英钠引起的牙龈增生被认为与钙信号有关，但其引起细胞内钙浓度（[Ca 2 +]i）升高的机制尚存在争议。本研究旨在阐明苯妥英钠诱导人牙龈成纤维细胞（HGF）[Ca 2 +] i升高的机制。在室温下，使用由耦合到倒置荧光显微镜的EM-CCD相机组成的成像系统捕获的Fura-2的荧光图像，在单细胞水平上检查HGF中的iin。苯妥英钠在细胞外Ca 2+不存在的情况下诱导[Ca 2 +] i一过性升高，表明苯妥英钠诱导的[Ca 2 +] i升高不需要细胞外Ca 2+内流。此外，苯妥英钠增加[Ca 2 +]iin的HGFs耗尽细胞内Ca 2+商店的毒胡萝卜素，表明既不涉及Ca 2+释放或抑制Ca 2+摄取。此外，在不存在细胞外Na+的情况下，苯妥英诱导的[Ca 2 +] i升高降至18.8%，在存在苯妥英的情况下，去除细胞外Na+后的[Ca 2 +] i升高降至25.9%。这些结果表明，苯妥英钠通过抑制Na+/Ca 2+交换增加HGF的[Ca 2 +] i。细胞内Ca 2+分泌的抑制被认为是增强由各种刺激诱导的Ca 2+反应。在单细胞水平上的分析表明，刺激与1 μM ATP或3 μM组胺增加[Ca 2 +] i在20-50%的细胞，和[Ca 2 +] i增加在许多无反应的细胞中，在存在的phenytoin.ConclusionOur的研究结果表明，phenytoin诱导的[Ca 2 +] i增加通过抑制Ca 2+流出在HGF。还发现，苯妥英钠通过抑制Ca 2+流出，强烈增强由低浓度ATP或组胺刺激诱导的小Ca 2+反应。这些结果表明，苯妥英可能通过与牙龈中的炎性生物活性物质相互作用导致药物诱导的牙龈过度生长。
Background and ObjectivesGingival overgrowth caused by phenytoin is proposed to be associated with Ca2+signaling; however, the mechanisms that increase the intracellular Ca2+concentration ([Ca2+]i) are controversial. The current study aimed to elucidate the mechanism underlying the phenytoin‐induced increase in [Ca2+]iin human gingival fibroblasts (HGFs).MethodsEffects of 100 μM phenytoin on [Ca2+]iin HGFs were examined at the single‐cell level using fluorescence images of fura‐2 captured by an imaging system consisting of an EM‐CCD camera coupled to an inverted fluorescence microscope at room temperature.ResultsExposure of HGFs to 100 μM phenytoin induced a transient increase in [Ca2+]iin the absence of extracellular Ca2+, indicating that the phenytoin‐induced increase in [Ca2+]idoes not require an influx of extracellular Ca2+. In addition, phenytoin increased [Ca2+]iin HGFs depleted of intracellular Ca2+stores by thapsigargin, indicating that neither Ca2+release from stores nor inhibition of Ca2+uptake is involved. Furthermore, the phenytoin‐induced [Ca2+]ielevation was reduced to 18.8% in the absence of extracellular Na+, and [Ca2+]ielevation upon removal of extracellular Na+was reduced to 25.9% in the presence of phenytoin. These results imply that phenytoin increases [Ca2+]iof HGFs by suppressing the Na+/Ca2+exchanger. Suppression of intracellular Ca2+excretion is thought to enhance the Ca2+responses induced by various stimuli. Analysis at the single‐cell level showed that stimulation with 1 μM ATP or 3 μM histamine increased [Ca2+]iin 20–50% of cells, and [Ca2+]iincreased in many unresponsive cells in the presence of phenytoin.ConclusionOur findings demonstrate that phenytoin induced increase in [Ca2+]iby the inhibition of Ca2+efflux in HGFs. It was also found that phenytoin strongly enhanced small Ca2+responses induced by stimulation with a low concentration of ATP or histamine by inhibiting Ca2+efflux. These findings suggest a possibility that phenytoin causes drug‐induced gingival overgrowth by interacting with inflammatory bioactive substances in the gingiva.