兔骨髓间充质干细胞的生物学特征及其对不同生长因子的反应

为了研究兔骨髓间充质干细胞（rBM—MSC）的生物学特征及其对不同生长因子的反应，使用贴壁培养法从兔骨髓单个核细胞中获得间充质干细胞（MSC），在光学显微镜和电子显微镜下观察其基本生长行为和生物学特征；使用流式细胞仪检测rBM—MSC的免疫学表型；RT—PCR法检测其胶原表达；诱导rBM—MSC多向分化并使用特异性染色和RT—PCR予以鉴定；最后使用MTT法检测IL—1、3、8和HGF对rBM—MSC生长增殖的影响。结果显示：贴壁生长的rBM—MSC具有典型的成纤维样细胞形态，可传15代以上，第5代rBM—MSC高表达基质受体CD44（32％），低表达造血细胞标记CD45（4．7％）；RT—PCR显示高表达Ⅰ型胶原，弱表达Ⅱ型胶原，不表达X型胶原；在不同的诱导条件下．rBM—MSC可被诱导分化为成骨细胞、软骨细胞、脂肪细胞和神经元样细胞。rBM—MSC对IL-3最为敏感．10ng／ml的低浓度IL-3可显著促进细胞增殖达32％以上（P〈0．01），而高浓度IL-3能显著抑制其生长。结论：分离培养了rBM—MSC，其生物学特征与人和猕猴等BM—MSC相似的生物学特性，低浓度IL-3可有效促进其增殖。

Biological Characteristics of Rabbit Bone Marrow Mesenchymal Stem Cells and Their Response to Different Growth Factors

This study was aimed to analyze the biological characteristics of rabbit bone marrow mesenchymal stem cells (rBM-MSCs) and their response to different growth factors. Rabbit BM-MSCs were separated from bone marrow mononuclear cells by using adherent cultivation. Biological characteristics were investigated by optical and electron microscopy. Immunophenotype of rBM-MSCs was measured by flow cytometry. The expression of collagen was detected by RT-PCR. Differentiation potential was identified by specific staining and RT-PCR. The response of rBM-MSCs to IL-1, 3, 8 and HGF with different concentrations were tested by MTT. The results showed that the rBM-MSCs gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast-like morphology and could be cultured for over 15 passages. CD44 was highly expressed on F5 rBM-MSCs (32%) and CD45 was lowly expressed (4.7%). Type I collagen was highly expressed, while type II collagen was lowly expressed and type X collagen was not detected on rBM-MSCs using RT-PCR method. In various conditions inducting differentiation, rBM-MSCs could differentiate into the osteoblast, chondrocyte, adipocyte and neuron-like cells. The rBM-MSCs were sensitive to IL-3, even low concentration (10 ng/ml) of IL-3 could promote the proliferation of rBM-MSCs effectively (>32%, P<0.01), whereas high concentration IL-3 inhibited it significantly. It is concluded that rabbit BM-MSCs were successfully isolated and culture-expanded. The biological characteristics of rabbit BM-MSCs are similar to those of human and rhesus BM-MSCs. IL-3 with low concentration can promote the proliferation of rBM-MSCs effectively, but high concentration of IL-3 can inhibit their proliferation.