Effects of spinal cord injury-induced impairment of meningeal lymphatic drainage on secondary neuroinflammation and neuronal injury of the brain
10.3760/cma.j.cn501098-20250523-00291
- VernacularTitle:脊髓损伤所致脑膜淋巴管引流功能障碍对大脑继发性神经炎症及神经元损伤的影响
- Author:
Yi CHEN
1
;
Yu TANG
1
;
Lingxia MIN
1
;
Mingliang TAN
1
;
Boya CONG
1
;
Jingming HOU
1
;
Zhou FENG
1
Author Information
1. 陆军军医大学第一附属医院康复医学科，重庆 400038
- Publication Type:Journal Article
- Keywords:
Spinal cord injuries;
Cerebrum;
Inflammation;
Neurons;
Meningeal lymphatic vessels
- From:
Chinese Journal of Trauma
2025;41(11):1103-1111
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To determine whether spinal cord injury (SCI) triggers secondary neuroinflammation and neuronal injury in remote brain regions by impairing the drainage function of the meningeal lymphatic vessels (MLVs).Methods:Fifty-two female C57BL/6 mice were assigned with the random number table into four groups ( n=13 per group): sham group, SCI group, adeno-associated virus negative control group (negative control group), and adeno-associated virus overexpressing VEGF-C group (VEGF-C group). The sham group underwent laminectomy without spinal cord injury. In the SCI group, negative control group and VEGF-C group, T 9 contusion was made to establish the SCI models using a modified Allen′s impactor. At 4 weeks before SCI modeling, the negative control group and VEGF-C group were injected via the cisterna magna with 3 μl adeno-associated virus for negative control or adeno-associated virus for VEGF-C overexpression. At 56 days after injury, Alexa Fluor? 647 ovalbumin conjugate (OVA-647) was injected via the cisterna magna as a tracer. Two hours later, the proportion of OVA-647 in the deep cervical lymph nodes (dCLN) was detected. Immunofluorescence was performed to assess the proportion of MLVs marker lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and expression levels of microglial marker ionized calcium-binding adaptor molecule 1 (Iba1) in the cerebral cortex, hippocampus, midbrain, and thalamus across the experimental groups. ELISA was employed to quantify the levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and Nissl staining was used to assess neuronal counts in these regions. Results:At 56 days after injury, the OVA-647 proportion in the dCLN was higher in the sham group than that in the SCI group and negative control group ( P<0.01), whereas the SCI group and negative control group showed a lower OVA-647 proportion in the dCLN than the VEGF-C group ( P<0.05). At 56 days after injury, the dural LYVE-1 proportion was higher in the sham group than that in the SCI group and negative control group ( P<0.01), whereas it was lower in the SCI group and negative control group than that in the VEGF-C group ( P<0.05). At 56 days after injury, the count of Iba1-positive microglia across all the above-mentioned regions was increased in the SCI group and negative control group ( P<0.01), compared with that in the sham group, whereas it was reduced in these regions in the VEGF-C group, compared with that in the SCI group and negative control group ( P<0.01). At 56 days after injury, TNF-α and IL-1β levels in these regions were both elevated in the SCI group and negative control group when compared with those in the sham group ( P<0.05), whereas they were reduced in the VEGF-C group, compared with those in the SCI group and negative control group ( P<0.05). At 56 days after injury, neuronal survival in the regions was decreased in the SCI group and negative control group, compared with that in the sham group ( P<0.05), whereas it was increased in the VEGF-C group, compared with that in the SCI group and negative control group ( P<0.05). Conclusion:SCI can induce secondary neuroinflammation and neuronal damage in remote brain regions by impairing the drainage function of MLVs.
