Intravenous Administration Of Bone Marrow Stromal Cells After Stroke In Rats And The Expression Of Bcl-2 Protein.

IntroductionBone marrow stromal cells are nonhematopoietic stem cells, also called mesenchymal stem cells. These cells have the capacity for self - renewal and multipotentiality for differentiation. MSCs produce fibrous tissue, bone, or cartilage and muscle when implanted into appropriate tissue in vivo. Recent study has shown that intravenous administration of bone marrow stromal cells reduces functional deficits associated with stroke. Some of these cells differentiate into astro-cytes and neurons and express neuronal nuclei ( NeuN) and glial fibrillary acidic protein ( GFAP). Bone marrow stromal cells could pass through the blood -brain barrier and migrate throughout forebrain and cerebellum.Researches have proved that intravenous administration of bone marrow stromal cells is a new therapy method with excellent prospect and needs deeper investigation. Nowadays, researches have been concentrated on the specific mechanism, through which the bone marrow stromal cells improve the recovery of nervous function.The first step of my study is to separate the bone marrow of the Wistar rats and culture the bone marrow stromal cells in vitro. Study the morphology of the cells with a phase contrast microscope and observe the living characteristics of the cells. Then identify the cells by immunohistochemical assessment which was used in the second step of my research. At last, I transplanted the bone marrow stromal cells into rats 48 hours after stroke and study how the bone marrow stromal cells promote the recovery of the nervous function after transplantation.Materials and MethodsThe study was devided into two parts.Part I In vitro isolation, cultivation and identification of Bone Marrow Stromal Cells of Wistar rats.Separate the bone marrow of the Wistar rats and culture the bone marrow stromal cells. Study the morphology of the cells with a phase contrast microscope and observe the living characteristics after subculture of the cells. Identify the cells by immunohistochemical assessment. Bone marrow stromal cells, which can adhere the wall, can be easily separated and quickly proliferated by culture. Bone marrow stromal cells can be separated 20 days after primary culture. The living characteristic of the cultured cells was quite stable before the fifth generation. Typical bone marrow stromal cells can be divided into two types. Form 1: The cell bodies were Fusiform shape, volum and number were little relatively. Form 2 was the main form, the cell bodies were thin and flat, the sense of stereo wasn' t strong, the colour of plasm was light.Part n Intravenous administration of bone marrow stromal cells after stroke in rats and the expression of Bcl-2 protein.Separate 24 rats into three groups: Group 1 (n = 8 ) middle cerebral artery occlusion (MCAO) ; Group 2 (n = 8) intravenous injection of saline 1ml 48 hours after MCAO; Group 3 ( n = 8 ) intravenous transplantation of bone marrow stromal cells 1 x 10 . Observe the Nervous Severity Score (NSS) of every rat everyday. All animals were put to death 8 days after MCAO. Display the expression of Bcl-2 protein by immunocytochemical stain.ResultsIn contrast to the control group, the NSS of the test group ameliorated significantly (P <0.001) and the expression of Bcl-2 protein improved greatly (P <0.001).ConclusionBone marrow stromal cells could protect the nervous function after stroke in many ways. Promoting the express of Bcl-2 protein in the brain and inhibiting the apoptosis may be one of the possible mechanisms.