Central to the progression of cerebral toxoplasmosis is the interaction of Toxoplasma gondii with the blood-brain barrier (BBB) endothelial cells. In the present work, we tested the hypothesis that inhibition of Wnt pathway signalling by the monovalent ionophore monensin reduces the growth of T. gondii infecting human brain microvascular endothelial cells (hBMECs) or microglial cells. The anti-parasitic effect of monensin (a Wnt signalling inhibitor) on the in vitro growth of T. gondii tachyzoites was investigated using two methods (Sulforhodamine B staining and microscopic parasite counting). The monensin inhibited T. gondii growth (50% inhibitory concentration [IC₅₀] = 0.61 μM) with a selective index = 8.48 when tested against hBMECs (50% cytotoxic concentration [CC₅₀] = 5.17 μM). However, IC₅₀ of monensin was 4.13 μM with a SI = 13.82 when tested against microglia cells (CC₅₀ = 57.08 μM), suggesting less sensitivity of microglia cells to monensin treatment. The effect of T. gondii on the integrity of the BBB was assessed by the transendothelial electrical resistance (TEER) assay using an in vitro human BBB model. The results showed that T. gondii infection significantly decreased hBMECs’ TEER resistance, which was rescued when cells were treated with 0.1 µM monensin, probably due to the anti-parasitic activity of monensin. We also investigated the host-targeted effects of 0.1 µM monensin on global gene expression in hBMECs with or without T. gondii infection. Treatment of hBMECs with monensin did not significantly influence the expression of genes involved in the Wnt signalling pathway, suggesting that although inhibition of the Wnt signalling pathway did not play a significant role in T. gondii infection of hBMECs, monensin was still effective in limiting the growth of T. gondii. On the contrary, monensin treatment downregulated pathways related to steroids, cholesterol and protein biosynthesis and their transport between endoplasmic reticulum and Golgi apparatus, and deregulated pathways related to cell cycle and DNA synthesis and repair mechanisms. These results provide new insight into the host-modulatory effect of monensin during T. gondii infection, which merits further investigation.

中文翻译：

---

弓形虫感染人脑微血管内皮细胞对莫能菌素治疗的转录组分析。

中部脑弓形体病的进展是相互作用弓形虫与血脑屏障（BBB）的内皮细胞。在本工作中，我们测试了以下假设：单价离子载体莫能菌素对Wnt信号通路的抑制作用会降低感染人脑微血管内皮细胞（hBMECs）或小神经胶质细胞的弓形虫的生长。使用两种方法（磺胺多巴胺B染色和微观寄生虫计数）研究莫能菌素（Wnt信号抑制剂）对弓形虫速殖子体外生长的抗寄生虫作用。莫能菌素抑制弓形虫的生长（抑制浓度为50％[IC ₅₀] = 0.61μM），针对hBMEC（50％细胞毒性浓度[CC ₅₀ ] = 5.17μM）进行测试时，选择性指数= 8.48 。但是，当针对小胶质细胞测试时，莫能菌素的IC ₅₀为4.13μM，SI = 13.82（CC ₅₀ = 57.08μM），表明小胶质细胞对莫能菌素处理的敏感性较低。的效果弓形虫在BBB的完整性通过使用体外人类BBB模型中的跨内皮电阻（TEER）测定法评估。结果表明弓形虫感染显着降低了hBMECs的TEER抵抗力，当用0.1 µM莫能菌素处理细胞时，这种作用得以挽救，这可能是由于莫能菌素的抗寄生虫活性。我们还研究了0.1 µM莫能菌素对有或没有弓形虫感染的hBMECs中整体基因表达的宿主靶向作用。用莫能菌素处理hBMECs不会显着影响Wnt信号通路中涉及的基因的表达，这表明尽管Wnt信号通路的抑制在hBMEC的弓形虫感染中没有显着作用，但莫能菌素仍然有效地限制了弓形虫的生长。相反，莫能菌素处理下调了与类固醇，胆固醇和蛋白质生物合成及其在内质网和高尔基体之间的运输有关的途径，并下调了与细胞周期以及DNA合成和修复机制有关的途径。这些结果提供了新的洞察莫能菌素在弓形虫感染期间的宿主调节作用的见解，值得进一步研究。