Abstract：
Titanium dioxide nanoparticles (TiO2 NPs) can reduce sperm number, but the mechanisms of defective spermatogenesis induced by TiO2 NPs have not been studied through cell-cell interactions at present. A kind of biomimetic three-dimensional blood-testis barrier microfluidic chip capable of intercellular communication was constructed with soft lithography techniques, including Sertoli cell (TM4), spermatogonia (GC-1) and vascular endothelial cell units, to study the mechanisms of TiO2 NPs-induced defective spermatogenesis. TM4 and GC-1 cells cultured in TiO2 NPs exposure and control chips were collected for transcriptomics and metabonomics analysis, and key proteins and metabolites in changed biological processes were validated. In TM4 cells, TiO2 NPs suppressed glucose metabolism, especially lactate production, which reduced energy substrate supply for spermatogenesis. TiO2 NPs also decreased the levels of key proteins and metabolites of lactate production. In GC-1 cells, TiO2 NPs disturbed chemokine signaling pathways regulating cell proliferation and interfered with glutathione metabolism. The Cxcl13, Stat3 and p-Stat3 levels and cell proliferation rate were decreased, and the GSR, GPX4 and GSH contents were increased in GC-1 cells in chips under TiO2 NPs treatment. The decrease in energy substrate supply for spermatogenesis and inhibition of spermatogonia proliferation could be the main mechanisms of defective spermatogenesis induced by TiO2 NPs.
摘要：
二氧化钛纳米粒子（TiO2NPs）可以减少精子数量，但是目前尚未通过细胞间相互作用研究TiO2NP诱导精子发生缺陷的机制。采用软光刻技术构建了一种具有细胞间通讯功能的仿生三维血睾丸屏障微流控芯片,包括支持细胞（TM4），精原细胞（GC-1）和血管内皮细胞单位，研究TiO2NPs诱导精子发生缺陷的机制。收集在TiO2NPs暴露和对照芯片中培养的TM4和GC-1细胞进行转录组学和代谢组学分析，并验证了改变的生物过程中的关键蛋白质和代谢物。在TM4细胞中，TiO2NPs抑制葡萄糖代谢，特别是乳酸生产，这减少了精子发生的能量底物供应。TiO2NP还降低了乳酸生产的关键蛋白质和代谢物的水平。在GC-1细胞中，TiO2NPs干扰调节细胞增殖的趋化因子信号通路并干扰谷胱甘肽代谢。Cxcl13、Stat3和p-Stat3水平和细胞增殖率降低,还有GSR,在TiO2NP处理下，芯片中GC-1细胞中的GPX4和GSH含量增加。精子发生能量底物供应的减少和精原细胞增殖的抑制可能是TiO2NPs诱导精子发生缺陷的主要机制。
