Small extracellular vesicles derived from umbilical cord mesenchymal stem cells repair blood-spinal cord barrier disruption after spinal cord injury through down-regulation of Endothelin-1 in rats.

Spinal cord injury could cause irreversible neurological dysfunction by destroying the blood-spinal cord barrier (BSCB) and allowing blood cells like neutrophils and macrophages to infiltrate the spinal cord. Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) found in the human umbilical cord have emerged as a potential therapeutic alternative to cell-based treatments. This study aimed to investigate the mechanism underlying the alterations in the BSCB permeability by human umbilical cord MSC-derived sEVs (hUC-MSCs-sEVs) after SCI. First, we used hUC-MSCs-sEVs to treat SCI rat models, demonstrating their ability to inhibit BSCB permeability damage, improve neurological repair, and reduce SCI-induced upregulation of prepro-endothelin-1 (prepro-ET-1) mRNA and endothelin-1 (ET-1) peptide expression. Subsequently, we confirmed that hUC-MSCs-sEVs could alleviate cell junction destruction and downregulate MMP-2 and MMP-9 expression after SCI, contributing to BSCB repair through ET-1 inhibition. Finally, we established an in vitro model of BSCB using human brain microvascular endothelial cells and verified that hUC-MSCs-sEVs could increase the expression of junction proteins in endothelial cells after oxygen-glucose deprivation by ET-1 downregulation. This study indicates that hUC-MSCs-sEVs could help maintain BSCB's structural integrity and promote functional recovery by suppressing ET-1 expression.

Extension of decompression to C2 doesn't affect the spinal sagittal parameters compared with standard open-door laminoplasty.

We modified and extended laminoplasty to the upper cervical spine on patients with canal stenosis associated with upper cervical spinal ossified lesions. However, whether the extended decompression range of laminoplasty can cause further effects on cervical stability is rarely studied at present. A retrospective study to analyze the relationship between the surgical levels and cervical sagittal parameters effects was performed in patients with cervical spondylosis myelopathy who had undergone posterior cervical expansive open-door laminoplasty with/without extending to C2. In total, 64 patients were divided into 2 groups according to the surgical levels. Radiologic outcomes of occipito-cervical angle (C0-2 Cobb angle), CL C27 Cobb angle, cervical sagittal vertical alignment, T1-Slope (T1S), T1S minus CL (T1S-CL), spino-cranial angle and center of the sella turcica-C7 SVA (St-SVA) were evaluated on lateral X-rays of the cervical spine at pre-operation, post-operation, and 2-year follow-up. The patient's health-related quality of life was obtained including neck disability index, Japanese orthopaedic association scores, and visual analog scale. Changes in sagittal parameters were observed in both groups after surgery. T1S, cervical sagittal vertical alignment, and T1S-CL significantly increased and CL decreased in 2 groups of patients postoperative. After a 2-year follow-up period, the C0-2 Cobb angle was found to increase compared to preoperative records. In addition, there were no significant differences in spino-cranial angle and st-SVA between preoperative and 2 years follow-up measurements. Health-related quality of life was improved in both groups and was not significantly different. Herein, the parameters indicated a tilting forward of the lower cervical spine and a more lordotic upper cervical spine to maintain a horizontal gaze in patients. However, C2 to 7 laminoplasty was performed to achieve satisfactory clinical results without significantly changing the spinal sagittal parameters.