N6-methyladenosine participates in mouse hippocampus neurodegeneration via PD-1/PD-L1 pathway

Wen Hu; Hongbo Xie; Yubing Zeng; Pei Pei; Xiaojun Zhan; Shan Wang; Zhenlin Wang

doi:10.3389/fnins.2023.1145092

N6-methyladenosine participates in mouse hippocampus neurodegeneration via PD-1/PD-L1 pathway

Front Neurosci. 2023 May 10:17:1145092. doi: 10.3389/fnins.2023.1145092. eCollection 2023.

Authors

Wen Hu¹, Hongbo Xie², Yubing Zeng³, Pei Pei³, Xiaojun Zhan⁴, Shan Wang³, Zhenlin Wang¹

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
² Department of Otorhinolaryngology, Huadong Hospital Affiliated to Fudan University, Shanghai, China.
³ Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, China.
⁴ Department of Otorhinolaryngology Head and Neck Surgery, Children's Hospital, Capital Institute of Pediatrics, Beijing, China.

Abstract

Developmental abnormalities and hippocampal aging leads to alteration in cognition. In the brain, N6-methyladenosine (m⁶A) is a common and reversible mRNA alteration that is essential for both neurodevelopment and neurodegeneration. However, its function in the postnatal hippocampus and the specific mechanisms regulating hippocampus-related neurodegeneration still awaits elucidate. We identified dynamic m⁶A modifications in postnatal hippocampus at different stages (at 10 days postnatally, and at 11 and 64 weeks of age). m⁶A shows a definite cell-specific methylation profile and m⁶A modification displays temporal dynamic during neurodevelopment and aging. Differentially methylated transcripts in the aged (64-week-old) hippocampus were enriched in microglia. The PD-1/PD-L1 pathways was identified that may participate in the cognitive dysfunction associated with an aged hippocampus. Furthermore, Mettl3 was spatiotemporally expressed in the postnatal hippocampus, which was highly expressed at the age of 11 weeks compared with the other two timepoints. Ectopic expression of METTL3 in mice hippocampus mediated by lentiviral infection resulted in high expression of genes related to PD-1/PD-L1 pathway and significant spatial cognitive deficit. Together, our data show that m⁶A dysregulation, which is mediated by METTL3, most likely contributes to cognitive deficits linked to the hippocampus via the PD-1/PD-L1 pathway.

Keywords: PD-1/PD-L1 pathway; aging; cognition; hippocampus; m6A; neurodevelopment.