Xinyu Mei1  · Yi Liu4,5 · Chuantao Fang3  · Jingjing Guo1  · Yanfeng Tan2  · Ying Shi2  · Jianbo Xiao4,6 · Dashi Qi1,2

1 Center for Clinical Research and Translational Medicine, Yangpu Hospital, School of Medicine, Tongji University, Shanghai 200090, China 

2 Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Brain Function and Disorders, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China 

3 Shanghai Tenth People’s Hospital, Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai 200072, China 

4 Nutrition and Bromatology Group, Department of Analytical Chemistry and Food Science, Faculty of Science, Universidade de Vigo, 32004 Ourense, Spain 

5 Xinjiang Key Laboratory of Functional Agriculture and Bio‑intelligent Manufacturing, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu National Agricultural Science and Technology Center, Chengdu 610213, China 

6 Instituto de Agroecoloxía e Alimentación (IAA), Universidade de Vigo, Campus Auga, 32004 Ourense, Spain

Abstract

Elevated homocysteine (Hcy) levels contribute to the onset and progression of childhood epilepsy. However, Hcy-lowering therapies provide limited benefits, suggesting additional pathogenic mechanisms. Here, we identified N-homocysteinylated Cofilin-1 (N-Hcy-CFL1) as a molecular link between elevated Hcy levels and childhood epilepsy. We detected N-Hcy-CFL1 in patients with epilepsy and in a mouse model of hyperhomocysteinemia. Mass spectrometry identified Hcy-dependent lysine modifications in CFL1, and functional assays, including actin depolymerization, the F/G-actin ratio, and axonal elongation, demonstrated impaired CFL1 activity and consequent cytoskeletal rigidity. These changes manifested as increased F-actin levels, increased F/G-actin ratio, and abnormal axonal growth. In vivo, hyperhomocysteinemic mice exhibited prolonged seizures and axonal remodeling, both of which were attenuated by CFL1-directed interventions. Clinically, blood Hcy levels correlated with N-Hcy-CFL1 levels in patients’ brain tissues, supporting its potential as a biomarker. Together, these findings identify N-Hcy-CFL1 as a pathogenic mediator and suggest that N-homocysteinylation is a therapeutic target beyond conventional Hcy-lowering strategies.

Keywords

Childhood epilepsy; Homocysteine; N-homocysteinylation; Cofilin-1; Actin dynamics; Therapeutic target

[SpringerLink]