Toll样受体激动剂对骨髓间充质干细胞成骨及成脂分化的影响

目的探讨人骨髓间充质干细胞（ BM-MSC）的多分化潜能及Toll样受体（ TLR）激动剂对其成骨及成脂分化能力的影响。方法从健康供者骨髓中分离培养BM-MSC，研究分析其向成骨及脂肪细胞的分化潜能；应用流式细胞术检测BM-MSC表面TLR2及TLR4的表达，在分化培养基中添加TLR2和TLR4激动剂，PAM3 CSK4或LPS，比较添加组与未添加组成骨及成脂分化能力改变情况；给予PAM3 CSK4或LPS预刺激BM-MSC 24 h，比较各组细胞成骨及成脂分化能力的改变。结果 BM-MSC能够诱导分化成成骨细胞及脂肪细胞。 PAM3 CSK4及 LPS 可促进 BM-MSC 向成骨细胞分化，而对 BM-MSC 的成脂分化能力无明显影响。PAM3 CSK4及LPS预刺激后，BM-MSC的成骨分化能力无显著性改变。结论 BM-MSC具有多分化潜能，TLR2及TLR4激动剂可促进BM-MSC向成骨细胞分化，此作用需要TLR激动剂的持续暴露，与BM-MSC表面TLR的短暂活化无关。

Effect of Toll-like receptor agonist on ability of bone marrow-mesenchymal stem cells to differentiate into osteoblasts and adi-pocytes

Objective To explore the differentiation potential of human bone marrow mesenchymal stem cells (BM-MSCs) and the effect of Toll-like receptor ( TLR) agonists on the ability of BM-MSCs to differentiate into osteoblasts and adipocytes.Methods BM-MSCs were isolated from the bone marrow of healthy donors.Study on differentiation of BM-MSCs into osteoblasts and adipocytes were done in vitro. The protein expression of TLR2 and TLR4 was evaluated by flow cytometry.Osteogenic and adipogenic potentials of BM-MSCs were evaluated as the TLR2 or TLR4 agonist, PAM3 CSK4 or LPS, was presented in the differentiation medium throughout the induction period.Moreover, osteogenic and adipogenic differentiation potentials of BM-MSCs pre-stimulated with PAM3 CSK4 or LPS were also investigated.Results BM-MSCs possessed the ability to differentiate into adipocytes and osteoblasts as cultured in the induction medium.Adipogenic differentiation was not altered in the presence of PAM3 CSK4 or LPS.Increased osteogenic differentiation was existed when PAM3 CSK4 or LPS was present in the induction medium.No effect of osteogenic and adipogenic differentiation of BM-MSCs was observed as they were pretreated with PAM3 CSK4 or LPS.Conclusion BM-MSCs possess multilineage differentiation potential and PAM3 CSK4 or LPS can promote osteogenic differentiation. This effect may be mediated by long exposure, but not by short-term activation of TLR.