Bone marrow mesenchymal stem cells ameliorate neurological deficits and blood-brain barrier dysfunction after intracerebral hemorrhage in spontaneously hypertensive rats

Spontaneous intracerebral hemorrhage (ICH) is a common and fatal subtype of stroke, with hypertension the most common cause of this disorder. Bone marrow derived mesenchymal stem cells (BM-MSCs) have been shown to elicit protective properties in stroke models. In the present study, male spontaneously hypertensive rats (SHR) were subjected to ICH by intracerebral injection with autologous blood, Wistar-Kyoto (WKY) rats were employed as control. The neurological function outcomes and blood-brain barrier (BBB) were assessed after BM-MSCs transplantation. Our results showed that BM-MSCs grafts via the tail vein significantly decreased the modified neurological severity score (mNSS) and the modified limb placing test (MLPT) score at 14 days after ICH, and the scores were gradually lowered till the end of test. Furthermore, BM-MSCs transplantation effectively attenuated the BBB permeability compared with the vehicle only group, as evidenced by the low level of Evans blue leakage in the BM-MSC group. In addition, we found that BM-MSCs grafts elevated the levels of tight junction associated protein occludin, and type IV collagen. Taken together, our results suggest that intravenously transplanted BM-MSCs exert therapeutic effects on ICH in spontaneously hypertensive rats. The underlying mechanisms are associated with the enhanced neurological function recovery and increased integrity of BBB. Our results provide the increased understanding of the underlying mechanisms and perspective of BMSCs in treatment for stroke.