Abstract

Aberrant neuroinflammation mediated by microglia exacerbates white matter demyelination and disrupts the neuronal microenvironment following traumatic brain injury (TBI). • tRF-3-Leu-AAG, a tRNA-derived small RNA (tsRNA), promotes anti-inflammatory cytokine via RNA interference (RNAi)-mediated targeting of target gene 3′UTRs. • Gpr17 is identified as a direct downstream target of tRF-3-Leu-AAG, with its expression showing a robust negative correlation with tRF-3-Leu-AAG levels. • Xuefu Zhuyu Decoction (XFZYD) restricts excessive neuroinflammation and ameliorates TBI-induced neuronal damage by regulating the tRF-3-Leu-AAG/ Gpr17 axis. • This study elucidates a molecular mechanism underlying XFZYD-mediated neuroprotection, providing a promising traditional Chinese medicine-based strategy for TBI treatment. Background Xuefu Zhuyu Decoction (XFZYD) is clinically applied to traumatic brain injury (TBI) based on its traditional function of activating blood circulation and eliminating stasis. However, its precise mechanism underlying its efficacy, particularly through epigenetic regulation, are poorly understood. Aim of the study We hypothesized that the neuroprotective effects of XFZYD post-TBI are mediated through the modulation of transfer RNA-derived small RNAs (tsRNAs), a key class of epigenetic regulators. This study aimed to delineate the specific tsRNA-dependent molecular pathway underlying XFZYD’s ability to mitigate neuroinflammation and facilitate neurological recovery. Materials and methods We employed a murine TBI model treated with XFZYD. Following comprehensive assessment of neurological, histopathological, and inflammatory outcomes to test the mice behavior. The anti-infammatory roles of tRF-3-Leu-AAG was investigated in vivo and in vitro . RNA sequencing and bioinformatics analysis revealed G protein-coupled receptor 17 ( Gpr17 ) is tRF-3-Leu-AAG’s target. The direct interaction between tRF-3-Leu-AAG and Gpr17 is validated by dual-luciferase assay