Improving Functional Outcome Following Bone Marrow Stromal Cells Transplantation To Brain Ventricle After Cerebral Ischemia In Rats

Although the mammalian brain has long been thought to be entirely postmitotic , the recent discovery has confirmed an existence of neural stem or progenitor cells in vagions of the adult mammalian brain. The precursors of nonhematopoietic tissues are referred to as mesenchymal stem cells or bone marrow stromal cells(BMSCs). These cells have attracted interest because or their capacity for selfrenewal in a number of nonhematopoietic tissues, their multipotentiality for differentiation, and their possible use for both cell and gene therapy. Some studies have shown that endogenous neural precursors can be induced in situ or in vitro to differentiate into mature neurons, in regioins of adult mammalian neocortex that do not normally undergo any neurogenesis. And BMSCs are also neural precursors. Some scholars found that BMSCs can survive for a long time in brain, and can improve the neurological function through part, vein and artery transplanted. Therefore, the present study was designed to observed the effect of neurological functional recovery of transplantation of BMSCs, and then to study the migration, differentiation of BMSCs.MATERIAL AND METHODIsolated BMSCs from Wistar rats were cultured in Dulbecco's minimum essential medium (DMEM) containing 10% fetal bovine serum (FBS) , 100U/mlpenicillin and streptomycin, pH 7.2. Then these explants were incubated at the atmosphere of 37 X and 95 % O2/5 % CO2 up to confluency. After BMSCs were proliferated, marked with BrdU and pre - differentiated in vitro,. the BrdU - marked BMSCs - derived - NSCs were transplanted into animals brains in the experimental and control groups through brain ventricle. And then their distributions were observed in varied brain areas histologically.RESULTSThere was no significant difference between rats with PBS and rats with BMSCs before transplantation. Rats transplantated with BMSCs had significantly lower NSS scores at day 14 compared with the control group. The amount of BrdU positive cells within damaged areas in the transplantation group were larger than that in the symmertrical brain area and the other brain areas in the same group as in the same brain area in control group. And 1.2% BrdU positive cells expressed NSE, 6% BrdU positive cells expressed GFAP.DISCUSSIONResults from the present study demonstrated that BMSCs play a key role in the cerebral ischemia. BMSCs transplanted can survive, migrate to the injury site and differentiate into neurons and astrocytes, and improve neurological function.Over the past century, intracerebral grafting has been employed to explore the function and plasticity of the CNS. Some scholars found that BrdU - reactive cells survived in the ischemic brain after MCAo. The numbers of bone marrow cells that survived in the ischemic boundary zone were approximately seven times more than in the normal brain at 7 days. The finding is similar to data obtained by the present study. It has been recently reported that intracerebral whole bone marrow transplantation after stroke in the adult rat activates the proliferation and differentiation of exogenous BMSCs to adopt neural or glia phenotype. The present study suggested that BrdU positive cells expressed NSE and GFAP.