Authors :
Presenting Author: Xiaorui Shi, MD student – Beijing tiantan hospital, Capital Medical University,China
Fei Zhu, PhD – Beijing tiantan hospital, Capital Medical University,China
Qun Wang, MD – Beijing Tiantan Hospital, Capital Medical University
Rationale:
N6-methyladenosine (m6A), a common chemical epigenetic modification among mRNA post-transcriptional modifications, implicated in various physiological and pathological processes, but its role in epilepsy is still unknown.Glucose metabolism plays a critical role in epileptogenesis. Glucose-1,6-bisphosphate, a glycolytic bypass product synthesized by phosphoglucomutase 2-like protein 1 (PGM2L1), is particularly abundant in neurons. This study aims to explore the antiepileptogenic and neuroprotective mechanisms of PGM2L1-mediated glucose metabolism in refractory epilepsy.
Methods:
In our study, we collected the epileptogenic foci of patients with drug-resistant epilepsy and performed whole-transcriptome sequencing along with RNA m6A methylation profiling to identify differentially expressed genes. Then, molecular analyses (quantitative real-time PCR, Western blot analysis and immunofluorescence) assessed PGM2L1 expression and its regulation by YTHDC1 in kainic acid-induced medial temporal lobe epilepsy mouse models. RIP-qPCR confirmed YTHDC1 binding to PGM2L1 mRNA, while dual-luciferase assays and polysome profiling evaluated m6A-mediated translational regulation. Next, we accessed the expression and function changes of YTHDC1/PGM2L1 in the in vitro 0-Mg2+ model of epilepsy with primary cultured neurons.
Results:
This study reveals that YTHDC1 regulates m6A methylation of PGM2L1, thereby inducing neuronal hyperexcitability and promoting epileptogenesis. MeRIP analysis of epileptogenic foci from drug-resistant epilepsy patients showed elevated m6A levels compared to controls. Epileptogenic foci and adjacent tissues exhibited differential methylation in 204 mRNA genes (FDR < 5%), with 138 showing increased m6A methylation. The mRNA level of the glycolytic protein PGM2L1 was upregulated despite decreased m6A modification on its transcripts. This upregulation is mediated by the m6A reader protein YTHDC1. In kainic acid-induced epilepsy models, knocking down PGM2L1 expression significantly reduced seizure severity. YTHDC1 overexpression or PGM2L1 knockdown attenuated neuronal hyperexcitability in vitro 0-Mg