Effect and mechanism of neurotrophin-3 ubiquitination via receptor on neurological function recovery after spinal cord injury in rats
10.3760/cma.j.issn.1671-0282.2025.05.011
- VernacularTitle:神经营养因子3经受体泛素化促进大鼠脊髓损伤后神经功能恢复的作用及机制
- Author:
Yan CONG
1
;
Zhide SUN
;
Yanfei WANG
;
Jian YU
Author Information
1. 承德医学院附属医院急诊科，承德 067000
- Keywords:
Neurotrophin-3;
Spinal cord injury;
Oligodendrocyte;
autophagy;
Ubiquitination
- From:
Chinese Journal of Emergency Medicine
2025;34(5):676-683
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the role and underlying mechanisms of neurotrophin-3 (NT-3) in promoting neurological functional recovery following spinal cord injury (SCI) in rats.Methods:In vivo: Fifteen 8-week-old SPF-grade Sprague-Dawley rats were randomly assigned (via a random number method) to three groups ( n=5 per group): sham-operated (Sham) group, SCI group, and SCI+NT-3 group. A spinal cord compression model was established using a clip method. NT-3 (20 μg/kg) was continuously infused into the subarachnoid space via a microinfusion pump for 7 days. The Basso-Beattie-Bresnahan (BBB) scale was used to assess locomotor function post-SCI, with scores below 21 indicating successful model establishment. Western blotting was performed to analyze the expression levels of NT-3, microtubule-associated protein 1 light chain 3B (LC3B), oligodendrocyte transcription factor 1 (Olig1), and myelin basic protein (MBP) at 1, 3, 5, and 7 days post-injury. In vitro: Oligodendrocytes were isolated from neonatal rat brain tissues, cultured (5×10 4/cm 2), and divided into four groups: oxygen-glucose deprivation (OGD) group, OGD+NT-3 group, OGD+NT-3+ubiquitination inhibitor (UCHL1) group, and OGD+NT-3+ubiquitination agonist (MG132) group. Western blotting was conducted to detect the expression levels of TrkC, Ub-TrkC, and LC3B in each experimental group. Immunofluorescence staining was utilized to observe LC3B aggregation in oligodendrocytes. Morphological alterations in cells were examined through microscopy. Statistical analysis was performed using one-way ANOVA, followed by pairwise comparisons using the least significant difference method. Results:Compared with the SCI group, the SCI+NT-3 group exhibited significant improvement in BBB scores, reduced autophagy levels, increased Olig1 and MBP expression, and elevated TRAF6 ubiquitin ligase expression (all P<0.05). At 5 h post-OGD, immunofluorescence revealed reduced LC3B aggregation and near-normal oligodendrocyte morphology in the OGD+NT-3 group. Compared to the OGD, OGD+NT-3, and OGD+NT-3+UCHL1 groups, the OGD+NT-3+MG132 group demonstrated increased Ub-TrkC expression and markedly reduced autophagy levels at 5-7 h (all P<0.05). The OGD+NT-3+UCHL1 group exhibited lower Ub-TrkC expression and elevated autophagy levels compared to the OGD+NT-3 group (all P<0.05). Conclusion:NT-3 inhibits oligodendrocyte autophagy through TrkC receptor ubiquitination, thereby maintaining oligodendrocyte survival and promoting neurological recovery after SCI in rats.
