Flaxseed oil attenuates PFOS-induced testicular damage by regulating RNA alternative splicing

Background: Perfluorooctane sulfonate (PFOS) is a persistent, widely present environmental pollutant, and its toxicity to male reproduction has gradually attracted attention. Flaxseed oil (FO) is a dietary oil abundant in α-linolenic acid and has been demonstrated to possess multiple health benefits. However, whether FO protects against PFOS-induced testicular injury and its mechanism remain unclear. Methods: C57/BL6 mice were gavaged with different concentrations of FO or PFOS (10 mg kg^-1) for 28 days. Blood and testicular tissues were collected for histopathology, proteomics, and biochemical and molecular analyses. Results: Our results showed that FO supplementation significantly attenuated PFOS-induced testicular injury, as indicated by histopathological changes, decreased oxidative stress level, increased sperm count, decreased rate of sperm malformation, and improved functional markers of spermatogenesis. Proteomic analysis showed that differentially expressed proteins were notably enriched in spliceosome pathways. Machine learning algorithms were used to screen the hub gene, and PRPF3 and PUF60 proteins were found to be important for FO to exert protective benefits to testicular injury. Western blot results confirmed that FO supplementation could increase the protein expression of PRPF3 and decrease the protein expression of PUF60 in PFOS-exposed mice. Conclusions: This study revealed that FO can alleviate PFOS-induced testicular dysfunction by regulating RNA alternative splicing. The spliceosome-related proteins PRPF3 and PUF60 may be the potential targets for FO to alleviate PFOS-induced testicular injury. FO supplementation may be an effective dietary intervention to prevent adverse effects of PFOS on testes.