The Role of Human Neural Stem Cell Secretomes on the Repair of Spinal Cord Injury Post-laminectomy in Rattus norvegicus Through the Analysis of Basso–Beattie–Bresnahan Score Locomotors, Interleukin-10, Matrix Metalloproteinase 9, and Transforming Growth Factor-β

STUDY DESIGN: Experimental animal study. PURPOSE: This study aims to investigate the effects of treatment with human neural stem cell (HNSC) secretomes on subacute spinal cord injury (SCI) post-laminectomy by analyzing interleukin-10 (IL-10), matrix metalloproteinase 9 (MMP9), transforming growth factor-β (TGF-β), and Basso–Beattie–Bresnahan (BBB) score locomotors as expressions of neurological recovery. OVERVIEW OF LITERATURE: In the United States, SCI has a recovery rate of 0.08%, tetraplegia 58.7%, and paraplegia 40.6%. Therapeutic approaches to SCI have focused on modulating the secondary cascade to prevent neurological deterioration and glial scar formation. Increasing evidence has shown that the success of cell-based SCI therapy is attributed to the secretomes rather than the cells themselves, but the effect of treatment with HNSC secretomes in SCI is unclear. METHODS: This experimental study investigated 15 Rattus norvegicus rats that were divided into three groups: (1) normal, (2) SCI+non-secretome, and (3) SCI+secretome (30 μL, intrathecal Th10). Model subacute SCI post-laminectomy was performed in 60 seconds using an aneurysm Yasargil clip with a closing forceps weighing 65 g (150 kdyn). At 35 days post-injury, the specimens were collected, and the immunohistochemicals of IL-10, MMP9, and TGF-β were analyzed. Motor recovery was evaluated based on the BBB scores. RESULTS: The SCI post-laminectomy of rats treated with HNSC secretomes showed improvements in their locomotor recovery based on the BBB scores (p=0.000, mean=18.4) and decreased MMP9 (p=0.015) but had increased the levels of IL-10 (p=0.045) and TGF-β (p=0.01). CONCLUSIONS: These results indicate that the factors associated with the HNSC secretomes can mitigate their pathophysiological processes of secondary damage after SCI and improve the locomotor functional outcomes in rats.