Downregulation of DDIT4 ameliorates abnormal behaviors in autism by inhibiting ferroptosis via the PI3K/Akt pathway

Autism spectrum disorder (ASD) is a complex disease with unclear etiology. Studies have shown that ferroptosis is also related to ASD progression, but the specific mechanism is still unclear. Valproic acid (VPA) induced neuronal ferroptosis in vitro. Mechanistic studies showed that both VPA and ferroptosis inducers promoted the expression of DDIT4 in neurons, thereby inhibiting the activation of the PI3K/Akt pathway. DDIT4 increased the accumulation of ROS, MDA and Fe2 thorn , inhibited neuronal viability and downregulated GPX4 expression by inactivating the PI3K/Akt pathway. Ferroptosis inhibitors reversed the anti-survival effect of DDIT4, indicating that DDIT4 enhances ferroptosis through the PI3K/Akt pathway, thereby inhibiting neuronal viability. Further in vivo experiments found that autistic mice had high levels of ROS, MDA and Fe2 thorn , increased DDIT4 expression, and downregulated expression levels of GPX4, p-PI3K and p-Akt; after downregulation of DDIT4 expression, the accumulation of ROS, MDA and Fe2 thorn was significantly reduced, while the expression levels of GPX4, p-PI3K and p-Akt were upregulated, indicating that DDIT4 knockdown reduces ferroptosis in autistic mice. In addition, DDIT4 down -regulation, PI3K/Akt pathway activation, and ferroptosis inhibitors all improved social behavior deficits, repetitive stereotyped and compulsive behaviors, anxiety and exploratory behaviors in autistic mice, but PI3K/Akt pathway inhibitors significantly blocked the rescue of abnormal behaviors by DDIT4 down -regulation in autistic mice. Therefore, downregulation of DDIT4 expression ameliorates abnormal be-haviors in autism by inhibiting ferroptosis via the PI3K/Akt pathway, indicating that DDIT4, the PI3K/Akt pathway and ferroptosis have key roles in autism.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Autism spectrum disorder (ASD) is a complex disease with unclear etiology. Studies have shown that ferroptosis, a form of cell death, is related to ASD progression, but the mechanism behind it is still unknown. Valproic acid (VPA) was found to induce ferroptosis in neurons, and the activation of the PI3K/Akt pathway was inhibited by VPA and other ferroptosis inducers. DDIT4, a protein, was found to play a role in promoting ferroptosis and inhibiting neuronal viability through the PI3K/Akt pathway. In mice with ASD, high levels of oxidative stress and ferroptosis markers were observed, along with increased DDIT4 expression and decreased expression levels of GPX4, p-PI3K, and p-Akt. Knockdown of DDIT4 expression reduced ferroptosis and improved abnormal behaviors in mice with ASD, indicating that DDIT4, the PI3K/Akt pathway, and ferroptosis play important roles in autism.