College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Songdogwahak-ro, Yeonsu-gu, Korea.
PLoS One. 2019 Sep 12;14(9):e0222326. doi: 10.1371/journal.pone.0222326. eCollection 2019.
Gap junctions (GJs), which consist of proteins called connexins, are intercellular channels that allow the passage of ions, second messengers, and small molecules. GJs and connexins are considered as emerging therapeutic targets for various diseases. Previously, we screened numerous compounds using our recently developed iodide yellow fluorescent protein gap junctional intercellular communication (I-YFP GJIC) assay and found that flunarizine (FNZ), used for migraine prophylaxis and as an add-on therapy for epilepsy, inhibits GJIC in LN215 human glioma cells. In this study, we confirmed that FNZ inhibits GJIC using the I-YFP GJIC assay. We demonstrated that FNZ inhibits GJ activities via a mechanism that is independent of calcium channels and dopaminergic D2, histaminergic H1, or 5-HT receptors. In addition, we showed that FNZ significantly increases connexin 43 (Cx43) phosphorylation on the cell surface, but does not alter the total amount of Cx43. The beneficial effects of FNZ on migraines and epilepsy might be related to GJ inhibition.
间隙连接（GJ）由连接蛋白组成，是允许离子、第二信使和小分子通过的细胞间通道。GJ 和连接蛋白被认为是各种疾病的新兴治疗靶点。此前，我们使用我们最近开发的碘化物黄色荧光蛋白缝隙连接细胞间通讯（I-YFP GJIC）测定法筛选了许多化合物，并发现用于偏头痛预防和癫痫附加治疗的氟桂利嗪（FNZ）抑制 LN215 人神经胶质瘤细胞中的 GJIC。在这项研究中，我们使用 I-YFP GJIC 测定法证实了 FNZ 抑制 GJIC。我们证明 FNZ 通过一种不依赖于钙通道和多巴胺能 D2、组氨酸能 H1 或 5-HT 受体的机制抑制 GJ 活性。此外，我们表明 FNZ 显著增加细胞表面连接蛋白 43（Cx43）的磷酸化，但不改变 Cx43 的总量。FNZ 对偏头痛和癫痫的有益作用可能与 GJ 抑制有关。
