T-2 toxin can induce bone and cartilage development disorder, and oxidative stress plays an important role in it. It is well known that selenomethionine (Se-Met) has antioxidative stress properties and promotes the repair of cartilage lesion, but it remains unclear whether Se-Met can relieve damaged cartilage exposure to T-2 toxin. Here, the oxidative stress and ferroptosis of chondrocytes exposure to T-2 toxin were observed. Mechanistically, T-2 toxin increased ROS, lipid ROS, MDA and Fe²⁺ contents in chondrocytes, decreased GSH and GPX4 activity, and inhibited the system Xc^-/GSH/GPX4 antioxidant axis. In addition, the mitochondria of chondrocytes shrunk and the mitochondrial crest decreased or disappeared. However, Fer-1 (Ferrostatin-1) inhibited ferroptosis induced by T-2 toxin in chondrocytes. The Se-Met alleviated lipid peroxidation, oxidative stress, and damaged mitochondrial in T-2 toxin-infected chondrocytes, enhanced antioxidant enzyme activity, and activated the system Xc^-/GSH/GPX4 axis, thereby antagonizing ferroptosis of chondrocytes and alleviating articular cartilage damage. In conclusion, our findings highlight the essentiality of ferroptosis in chondrocyte caused by T-2 toxin, elucidate how Se-Met offers protection against this injury and provide research evidence for the drug treatment target of Kashin-Beck disease.

Background: The intellectual loss induced by fluoride exposure has been extensively studied, but the association between fluoride exposure in different susceptibility windows and children’s intelligence is rarely reported. Hence, we conducted a cross-sectional study to explore the association between fluoride exposure in prenatal and childhood periods and intelligence quotient (IQ). Methods: We recruited 633 local children aged 7–13 years old randomly from four primary schools in Kaifeng, China in 2017. The children were divided into four groups, of which included: control group (CG, n = 228), only prenatal excessive fluoride exposure group (PFG, n = 107), only childhood excessive fluoride exposure group (CFG, n = 157), both prenatal and childhood excessive fluoride exposure group (BFG, n = 141). The concentrations of urinary fluoride (UF) and urinary creatinine (UCr) were determined by fluoride ion-selective electrode assay and a creatinine assay kit (picric acid method), respectively. The concentration of UCr-adjusted urinary fluoride (CUF) was calculated. IQ score was assessed using the second revision of the Combined Raven’s Test-The Rural in China (CRT-RC2). Threshold and saturation effects analysis, multiple linear regression analysis and logistic regression analysis were conducted to analyze the association between fluoride exposure and IQ. Results: The mean IQ score in PFG was respectively lower than those in CG, CFG and BFG (P < 0.05). The odds of developing excellent intelligence among children in PFG decreased by 51.1% compared with children in CG (OR = 0.489, 95% CI: 0.279, 0.858). For all the children, CUF concentration of ≥1.7 mg/L was negatively associated with IQ scores (β = − 4.965, 95% CI: − 9.198, − 0.732, P = 0.022). In children without prenatal fluoride exposure, every 1.0 mg/L increment in the CUF concentration of ≥2.1 mg/L was related to a reduction of 11.4 points in children’s IQ scores (95% CI: − 19.2, − 3.5, P = 0.005). Conclusions: Prenatal and childhood excessive fluoride exposures may impair the intelligence development of school children. Furthermore, children with prenatal fluoride exposure had lower IQ scores than children who were not prenatally exposed; therefore the reduction of IQ scores at higher levels of fluoride exposure in childhood does not become that evident.