Bone marrow derived mesenchymal stem cells alleviated brain injury via down-regulation of interleukin-1β in focal cerebral ischemic rats

Interleukin-1β (IL-1β) plays an important role in brain injury after focal ischemia, and bone marrow-derived mesenchymal stem cells (BMSCs) are capable of reducing the expression of IL-1β, we investigated the effects of BMSCs transplantation on brain edema and cerebral infarction as well as the underlying mechanisms via IL-1β. Male Sprague-Dawley rats were randomly divided into five groups: Normal + phosphate-buffered saline (PBS), middle cerebral artery occlusion (MCAO) + PBS, Normal + BMSCs, MCAO + BMSCs and MCAO + IL-1ra (an antagonist of IL-1β). BMSCs were transplanted 24 hours after MCAO, and brain edema was evaluated by Magnetic Resonance Imaging (MRI) and brain water content method after BMSCs transplantation. The expression of NeuN and AQP4 was analyzed by immunofluorescence staining. Protein level of AQP4 and IL-1β was detected by western blot analysis 48 hours after transplantation. The results showed that BMSCs transplantation reduced brain edema by measurement of brain water content and ADC Value of MRI, as well as the expression of AQP4 and IL-1β. It was also found that BMSCs transplantation could alleviate the cerebral infarction volume and neuronal damage. Both the brain edema and the cerebral infarction were associated with IL-1β expression. In conclusion, BMSCs transplantation was capable of alleviating brain edema as well as reducing cerebral infarction via down-regulation of IL-1β expression, thus repair the injured brain in focal cerebral ischemic rats.