Rodriguez-Iglesias Noelia, Paris Iñaki, Valero Jorge, Cañas-Zabala Lorena, Carretero Alejandro, Hatje Klas, Zhang Jitao David, Patsch Christoph, Britschgi Markus, Gutbier Simon, Sierra Amanda
Glial Cell Biology Lab, Achucarro Basque Center for Neuroscience, Leioa, Spain.
Department of Neuroscience, University of the Basque Country EHU/UPV, Leioa, Spain.
Glia. 2025 Feb;73(2):330-351. doi: 10.1002/glia.24637. Epub 2024 Nov 4.
Phagocytosis is an indispensable function of microglia, the brain professional phagocytes. Microglia is particularly efficient phagocytosing cells that undergo programmed cell death (apoptosis) in physiological conditions. However, mounting evidence suggests microglial phagocytosis dysfunction in multiple brain disorders. These observations prompted us to search for phagocytosis modulators (enhancers or inhibitors) with therapeutic potential. We used a bottom-up strategy that consisted on the identification of phagocytosis modulators using phenotypic high throughput screenings (HTSs) in cell culture and validation in organotypic cultures and in vivo. We performed two complementary HTS campagnes: at Achucarro, we used primary cultures of mouse microglia and compounds of the Prestwick Chemical Library; at Roche, we used human iPSC derived macrophage-like cells and a proprietary chemo-genomic library with 2200 compounds with known mechanism-of-action. Next, we validated the more robust compounds using hippocampal organotypic cultures and identified two phagocytosis inhibitors: trifluoperazine, a dopaminergic and adrenergic antagonist used as an antipsychotic and antineoplastic; and deoxytubercidin, a ribose derivative. Finally, we tested whether these compounds were able to modulate phagocytosis of apoptotic newborn cells in the adult hippocampal neurogenic niche in vivo by administering them into the mouse hippocampus using osmotic minipumps. We confirmed that both trifluoperazine and deoxytubercidin have anti-phagocytic activity in vivo, and validated our bottom-up strategy to identify novel phagocytosis modulators. These results show that chemical libraries with annotated mechanism of action are an starting point for the pharmacological modulation of microglia in drug discovery projects aiming at the therapeutic manipulation of phagocytosis in brain diseases.
吞噬作用是小胶质细胞（大脑中的专业吞噬细胞）不可或缺的功能。小胶质细胞是特别高效的吞噬细胞，在生理条件下能够吞噬经历程序性细胞死亡（凋亡）的细胞。然而，越来越多的证据表明，在多种脑部疾病中存在小胶质细胞吞噬功能障碍。这些观察结果促使我们寻找具有治疗潜力的吞噬作用调节剂（增强剂或抑制剂）。我们采用了一种自下而上的策略，该策略包括在细胞培养中使用表型高通量筛选（HTS）鉴定吞噬作用调节剂，并在器官型培养物和体内进行验证。我们进行了两项互补的HTS实验：在阿楚卡罗，我们使用了小鼠小胶质细胞的原代培养物和普雷斯蒂克化学文库中的化合物；在罗氏公司，我们使用了人诱导多能干细胞衍生的巨噬细胞样细胞和一个拥有2200种具有已知作用机制化合物的专有化学基因组文库。接下来，我们使用海马器官型培养物验证了更有效的化合物，并鉴定出两种吞噬作用抑制剂：三氟拉嗪，一种用作抗精神病药和抗肿瘤药的多巴胺能和肾上腺素能拮抗剂；以及脱氧胸苷，一种核糖衍生物。最后，我们通过使用渗透微型泵将这些化合物注入小鼠海马体，测试它们是否能够在体内调节成年海马神经发生微环境中凋亡新生细胞的吞噬作用。我们证实，三氟拉嗪和脱氧胸苷在体内均具有抗吞噬活性，并验证了我们自下而上的策略以鉴定新型吞噬作用调节剂。这些结果表明，具有注释作用机制的化学文库是药物发现项目中对小胶质细胞进行药理学调节的起点，这些项目旨在治疗性地调控脑部疾病中的吞噬作用。
