Characterization of Transplanted GFP⁺ Bone Marrow Cells into Adipose Tissue
绿色荧光蛋白标记的骨髓基质细胞移植入脂肪组织后的特性研究

Following transplantation of green fluorescent protein (GFP)-labeled bone marrow (BM) into irradiated, wild-type Sprague-Dawley rats, propagated GFP⁺ cells migrate to adipose tissue compartments. In order to determine the relationship between GFP+ BM-derived cells and tissue. resident GFP⁻ cells on the stem cell population of adipose tissue, we conducted detailed immunohistochemical analysis of chimeric whole fat compartments and subsequently isolated and characterized adipose-derived stem cells (ASCs) from GFP⁺ BM chimeras. In immunohistochemistry, a large fraction of GFP+ cells in adipose tissue were strongly positive for CD45 and smooth muscle actin, and evenly scattered around the adipocytes and blood vessels, while all CD45⁺ cells within the blood vessels were GFP⁺. A small fraction of GFP⁺ cells with mesenchymal marker CD90 also existed in the perivascular area. Flow cytometric and immunocytochemical analyses showed that cultured ASCs were CD45⁻/CD90⁺/CD29⁺. There was a significant difference in both the cell number and phenotype of the GFP⁺ ASCs in two different adipose compartments, the omental (abdominal) and the inguinal fat (subcutaneous) pad; a significantly higher number of GFP⁻/CD90⁺ cells were isolated from the subcutaneous depot as compared to the abdominal depot. The in vitro adipogenic differentiation of the ASCs was achieved; however, all cells that had differentiated were GFP⁻. Based on phenotypical analysis, GFP⁺ cells in adipose tissue in this rat model appear to be of both hematopoietic and mesenchymal origin; however,infrequent isolation of GFP⁺ ASCs and their lack of adipogenic differentiation suggest that the contribution of BM to ASCs generation might be minor.