[Bone marrow stem cell-derived astrocytes are involved in glia limitans formation in rats after brain injury].

OBJECTIVE: To investigate the involvement of bone marrow stem cell-derived astrocytes (BMDSCs) in the formation of glia limitans after brain injury. METHODS: In a female SD rat model of brain injury, green fluorescence protein (GFP)-labeled BMDSCs from male SD rats were transplanted via the caudal vein 24 h after the injury. The rats were sacrificed at 2, 4 and 8 weeks after the transplantation, and immunohistochemistry for glial fibrillary acidic protein (GFAP) was performed to observe the astrocytes. The fluorescence emitted by GFP was observed to identify the presence of the bone marrow-derived stem cells, and the GFAP(+)/GFP(+) cells in the glia limitnas were detected under fluorescence microscopy. RESULTS The GFAP(+)/GFP(+) cells were found in the glia limitans between the brain lesion and normal brain tissue. CONCLUSION: Bone marrow stem cell-derived astrocytes is involved in glia limitans formation after brain injury, which can be of significance in brain injury recovery and implantation of engineered materials.

[Differentiation of bone marrow-derived stem cells in injured rat brain tissue].

OBJECTIVE: To investigate the differentiation of bone marrow-derived stem cells (BMDSCs) migrated from blood circulation and resided in the injured brain tissue. METHODS: Brain injury model was established by iridectomy in the right cerebral cortex of female SD rats. Twenty-four hours after brain injury, the female rats received the implantation of green fluorescence protein (GFP)-labeled BMDSCs from male SD rats and were sacrificed at 2, 4 and 8 weeks after the implantation. Fluorescent immunohistochemistry for CD11b and glial fibrillary acidic protein (GFAP) on the brain sections was used to detect the GFP-positive cells. RESULTS: One week after the transplantation of the GFP-labeled BMDSCs, 3.53% of the peripheral blood white cells were GFP-positive; at 4 weeks and 8 weeks, a significant number of GFP-positive cells were found at the injury sites, some of which expressed CD11b and others expressed GFAP. CONCLUSION: GFP-labeled BMDSCs can migrate to the injured brain tissue and differentiate into cells that express microglia- and astrocytes-specific antigens.

[Identification of bone marrow stromal cells and expression of tyrosine hydroxylase gene in them].

The study is to establish the method of isolation and identification of bone marrow stromal cells and to investigate the ability of bone marrow stromal cells to accept and express TH gene. Cells were isolated by a density gradient (lymphocytes separation) and identified by BrdU labeling and fluorescence-activated cell sorting (FACS) technology using CD11b, CD45 and CD90 antibodies. TH and lacZ gene were transfected to rBMSCs with an adeno-associated virus vector. The results showed that most tightly adherent cells in the primary culture were fibroblast-like and formed foci of two to four cells. The cells in the foci remained dormant for 2 to 4 days and then began to multiply rapidly. After several passages, the adherent cells became more uniformly spindle-shaped in appearance. BrdU, indicating that BMSCs replicate actively, labeled about 74.9% of cultured cells. Data from FACS showed that about 75% of isolated cells were CD90(+)/CD45(-)/CD11b(-), which is the marker of bone marrow stromal cells. The efficiency of TH gene transfection was about 75%. BMSCs could readily be genetically engineered and could be useful delivery targets of gene therapy for Parkinson's disease.