College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong, Shanxi, 030800, PR China.
College of Animal Science, Shanxi Agricultural University, Jinzhong, Shanxi, 030800, PR China.
Environ Pollut. 2024 Mar 1;344:123332. doi: 10.1016/j.envpol.2024.123332. Epub 2024 Jan 8.
Fluoride is widely found in groundwater, soil, animal and plant organisms. Excessive fluoride exposure can cause reproductive dysfunction by activating IL-17A signaling pathway. However, the adverse effects of fluoride on male reproductive system and the mechanisms remain elusive. In this study, the wild type and IL-17A knockout C57BL/6J mouse were treated with 24 mg/kg·bw·d sodium fluoride and/or 5 mg/kg·bw·d riboflavin-5'-phosphate sodium for 91 days. Results showed that fluoride caused dental fluorosis, increased the levels of ROS in testicular Leydig cells and GSSG in testicular tissue, and did not affect the iron and serum hepcidin levels in testicular tissue. Riboflavin alleviated above adverse changes, whereas IL-17A does not participate in the oxidative stress-mediated reproductive toxicity of fluoride. Based on this, TM3 cells were used to verify the injury of fluoride on Leydig cells. Results showed that fluoride increased mRNA levels of ferroptosis marker SLC3A2, VDAC3, TFRC, and SLC40A1 and decreased Nrf2 mRNA levels in TM3 cells. The ferroptosis inhibitor Lip-1 and DFO were used to further investigate the relationship between male reproductive toxicity and ferroptosis induced by fluoride. We found that the fluoride-induced decrease in cell viability, increase in xCT, TFRC, and FTH protein expression, and decrease in GPX4 protein expression, can all be rescued by Lip-1 and DFO. Similar results were also observed in the riboflavin treatment group. Moreover, riboflavin mitigated fluoride-induced increases in ROS levels and SLC3A2 protein levels. In all, our work revealed that riboflavin inhibited ferroptosis in testicular Leydig cells and improved the declined male reproductive function caused by fluoride. This study provides new perspectives for revealing new male reproductive toxicity mechanisms and mitigating fluoride toxicity damage.
氟广泛存在于地下水、土壤、动植物组织中。过量的氟暴露可通过激活白细胞介素 17A 信号通路导致生殖功能障碍。然而，氟对雄性生殖系统的不良影响及其机制仍不清楚。在这项研究中，野生型和白细胞介素 17A 敲除 C57BL/6J 小鼠分别用 24mg/kg·bw·d 氟化钠和/或 5mg/kg·bw·d 核黄素 5'-磷酸钠盐处理 91 天。结果表明，氟导致氟斑牙，增加睾丸间质细胞 ROS 水平和睾丸组织 GSSG，不影响睾丸组织铁和血清铁调素水平。核黄素缓解了上述不良变化，而白细胞介素 17A 不参与氟引起的氧化应激介导的生殖毒性。基于此，TM3 细胞用于验证氟对间质细胞的损伤。结果表明，氟增加了 TM3 细胞铁死亡标志物 SLC3A2、VDAC3、TFRC 和 SLC40A1 的 mRNA 水平，并降低了 Nrf2 的 mRNA 水平。铁死亡抑制剂 Lip-1 和 DFO 进一步研究了氟引起的雄性生殖毒性与铁死亡之间的关系。我们发现，氟诱导的细胞活力下降、xCT、TFRC 和 FTH 蛋白表达增加以及 GPX4 蛋白表达降低，均可被 Lip-1 和 DFO 挽救。核黄素处理组也观察到类似的结果。此外，核黄素减轻了氟化物诱导的 ROS 水平和 SLC3A2 蛋白水平的升高。总之，我们的工作表明，核黄素抑制了睾丸间质细胞中的铁死亡，并改善了氟引起的雄性生殖功能下降。本研究为揭示新的雄性生殖毒性机制和减轻氟毒性损伤提供了新的视角。
