Unraveling the Nrf2-ARE Signaling Pathway in the DF-1 Chicken Fibroblast Cell Line: Insights into T-2 Toxin-Induced Oxidative Stress Regulation

The T-2 toxin (T2) poses a major threat to the health and productivity of animals. The present study aimed to investigate the regulatory mechanism of Nrf2 derived from broilers against T2-induced oxidative damage. DF-1 cells, including those with normal characteristics, as well as those overexpressing or with a knockout of specific components, were exposed to a 24 h treatment of 50 nM T2. The primary objective was to evaluate the indicators associated with oxidative stress and the expression of downstream antioxidant factors regulated by the Nrf2-ARE signaling pathway, at both the mRNA and protein levels. The findings of this study demonstrated a noteworthy relationship between the up-regulation of the Nrf2 protein and a considerable reduction in the oxidative stress levels within DF-1 cells (p < 0.05). Furthermore, this up-regulation was associated with a notable increase in the mRNA and protein levels of antioxidant factors downstream of the Nrf2-ARE signaling pathway (p < 0.05). Conversely, the down-regulation of the Nrf2 protein was linked to a marked elevation in oxidative stress levels in DF-1 cells (p < 0.05). Additionally, this down-regulation resulted in a significant decrease in both the mRNA and protein expression of antioxidant factors (p < 0.05). This experiment lays a theoretical foundation for investigating the detrimental impacts of T2 on broiler chickens. It also establishes a research framework for employing the Nrf2 protein in broiler chicken production and breeding. Moreover, it introduces novel insights for the prospective management of oxidative stress-related ailments in the livestock and poultry industry.

[Protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats]

Objective: To investigate the protective effect and immune mechanism of berberine on cerebral ischemia/reperfusion injury in rats. Methods: Fifty SD rats were randomly divided into sham operation group (Sham), model group (Model), berberine low dose groups (BBR-L, 25 mg/kg), berberine medium dose groups (BBR-M, 50 mg/kg) and berberine high dose groups (BBR-H, 100 mg/kg), with 10 rats in each group. Longa suture method was used to establish a rat model of cerebral ischemia/reperfusion, after 2 hours of ischemia, reperfusion for 24 hours. Rats in BBR-L, BBR-M and BBR-H were treated with berbrerine by gavage 2 hours after successful model building, while the sham operation group and the modle group were given the same volume of saline as described above. After 24 hours of administration, the activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), cytokine tumor necrosis factor α (TNF-α) , interferon β (IFN-β) , interleukin 6 (IL-6) and nitric oxide (NO) content were detected by ELISA assay. Serum CD4⁺, CD8⁺ and CD4⁺/CD8⁺ contents were measured by flow cytometry to investigate the immune function of each group. RT-qPCR and Western blot were used to detect NF-kappaB-NOD-like receptors 3 (NF-κB-NLRP3) signal axis key genes and protein expression in rat brain tissue. Results: Compared with the sham operation group, the degree of neurological deficit and the rate of cerebral infarction were increased in the model group (P＜0.05), and the levels of serum NO, TNF-α, IFN-β, IL-6, NF-κB p65, NLRP3, ASC and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4⁺, CD8⁺ and CD4⁺/CD8⁺ in serum were decreased (P＜0.05). Compared with the model group, the degree of neurological deficit and the rate of cerebral infarction were increased in the BBR-H, BBR-M and BBR-L groups (P＜0.05), and the levels of serum NO, TNF-α, IFN-β, IL-6, NF-κB p65, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 in brain tissue were increased (P＜0.05), while the activities of SOD, GSH-Px and the levels of CD4⁺, CD8⁺ and CD4⁺/CD8⁺ in serum were decreased (P＜0.05). Conclusion: Berberine may reduce oxidative stress, inhibit inflammation, enhance immune function, and reduce cerebral ischemia/reperfusion injury in rats, which may be related to the inhibition of NF-κB-NLRP3 signaling.