Oncostatin M-induced upregulation of SDF-1 improves Bone marrow stromal cell migration in a rat middle cerebral artery occlusion stroke model

Abstract

Bone marrow-derived mesenchymal stem cells (BMSCs) exhibit potential regenerative effects on the injured brain. However, these effects are constrained by their limited ability to migrate to the injured site. Oncostatin M (OSM) has been shown to affect the proliferation and migration of mesenchymal stem cells. Therefore, in the present study, we explored whether OSM improves BMSC migration and secretion of growth factors and cytokines in a rat middle cerebral artery occlusion (MCAO) stroke model. The effect of OSM on the proliferation and apoptosis of rat BMSCs was first assessed in vitro, and the gene and secretion levels of factors related to cell nutrition and migration, such as SDF-1 and VEGF, were detected. To further explore underlying pathways triggered by OSM, BMSCs were treated with OSM in the presence or absence of inhibitors of the STAT3 and ERK pathways. Effects of OSM on SDF-1 expression in astrocytes and BMSC migration were also evaluated. In the rat MCAO model, OSM secretion levels were detected in the brain for up to 72 h after model establishment. Ventricle injection of OSM alone or OSM combined with caudal vein graft of BMSCs was then performed in MCAO stroke rats. After 72 h, production of SDF-1 and grafted BMSCs was detected in the lesion areas of the brain, and the nerve function score was evaluated. We found that the production of OSM continually increased in the brains of MCAO rats from 12 h to 72 h. OSM significantly upregulated SDF-1 in BMSCs via the STAT3 and ERK pathways and significantly promoted the expression of VEGF and MMP-2. OSM also promoted the secretion of SDF-1 in astrocytes through the STAT3 and ERK pathways to in turn enhance BMSC migration. Combination treatment with OSM and BMSCs in MCAO rats increased the migration efficiency of BMSCs in the brain, which significantly improved neurofunctional recovery while reducing the expression of inflammatory mediators and promoting the secretion of nutrition factors. Overall, these results show that OSM is highly expressed in the brains of MCAO stroke rats and can upregulate SDF-1 to promote BMSC migration. Thus, combination treatment with OSM and BMSCs improves the graft efficiency of BMSCs and neurofunctional recovery.