Neuroprotective response and efficacy of intravenous administration of mesenchymal stem cells in traumatic brain injury mice.

Cellular transplantation of stem cells can be a beneficial treatment approach for neurodegenerative diseases such as traumatic brain injury (TBI). In this study, we investigated the proliferation and differentiation potential of infused mesenchymal stem cells (MSCs) after localisation at the injury site. We evaluated the appropriate homing of infused MSCs through immunohistochemistry, followed by Y-chromosome-specific polymerase chain reaction and fluorescent in situ hybridisation analyses. The proliferation and differentiation of infused MSCs were analysed using exogenous cell tracer 5'-bromo-2'-deoxyuridine (BrdU) labelling and neuronal specific markers, respectively. Structural and functional recovery in TBI mice were examined by performing magnetic resonance imaging and different behavioural assessments, respectively. Results demonstrated a significantly high number of BrdU-positive cells in the lesion region in the MSC-infused group compared with control and TBI groups. Infused MSCs were well differentiated into neural-like cells and expressed significantly more neural markers (neuronal nuclear antigen [NeuN], microtubule-associated protein 2 [MAP2] and glial fibrillary acid protein [GFAP]). Improved tissue abnormalities as well as functional behaviours were observed in MSC-infused TBI mice, implying the substantial proliferation and differentiation of infused MSCs. Our findings support the neuroprotective response and efficacy of MSCs after transplantation in TBI mice, and MSCs may serve as potential therapeutic candidates in regenerative medicine.