Therapeutic benefit of intravenous and focal administration of bone marrow stromal cells in stroke rat

Abstract

It was reported that the transplantation of the mesenchymal stem cell (MSC) protects against the cerebral infarction in the acute phase. Using transgenic rat that express the enhanced green fluorescent protein (EGFP), we investigated migration of MSCs in floresense microscopy and the infarction volume was measured with the use of 2, 3, 5-triphenyltetrazolium chloride (TTC) stain.The EGFP enhanced MSC were transplanted 3 h after the transient 90 min the middle cerebral artery occlusion. The animals were allowed to survive for 48 hours after stroke and the migration of transplanted MSCs were examined with fluorescence microscopy. The routes of the transplantation were intraventricle, intracerebral, intravenous and intracisterna magna. The MSC were distributed mostly in the penanbra area and the distribution pattern was as fillowes:
(1) Intraventricle route ; the MSCs were significantly distributed in the striatum of paraventricle area and few in the cortex. (2) Intracerebral route ; the MSC were prominently distributed in the striatum but few in the cortex. (3) Intravenous route ; the MSC were averagely in the striatum and the cortex. (4) Intracisterna magna route ; the MSC were sparsely in the striutum and aboundingly in the cortex.
The MSCs showed a tendency to distribute in the striatum more than in the cortex. However, the infarction volume was reduced in the striatum than the cortex. The distribution of MSCs were not correlated to protective effect. The precise mechanism of the neuroprotective effects of MSC in the rat after MCAO is not known. A reasonable hypothesis, more consistent with our findings, is that the interaction of MSC with the ischemic brain microenviroment leads to production of trophic factors, which reduce apoptosis in the cortex and striatum.