WNT激活剂对人骨髓基质干细胞成脂-成骨分化的影响

Effects of WNT activator on adipocytogenesis.osteocytogenesis of human bone marrow stromal cells

目的观察WNT信号通路激活剂SB-216763对于人骨髓基质干细胞（hBMSCs）成脂．成骨分化的影响。方法从3例临床股骨头标本中分离培养hBMSCs与5μmol／LSB-216763共同培养，观察hBMSCs表达β-连锁蛋白（β-catenin）的变化，检测hBMSCs增殖能力、成脂分化能力和成骨细胞诱导分化时碱性磷酸酶（ALP）活性的变化。结果SB-216763可以显著促进hBMSCs表达β-catenin（30．2±2．7比13．3±2．1，P〈0．01）、促进hBMSCs增殖（P〈0．01）、抑制hBMSCs向脂肪细胞分化[油红O（OilRed—O）阳性细胞数：27．4±3．2比8．4±2．1，P〈0．01]、降低hBMSEs的ALP活性（P〈0．01）。结论激活WNT信号通路可以促进hBMSCs的增殖，抑制hBMSCs向脂肪细胞分化并且抑制hBMSCs的成骨活性。

Objective To investigate the effects of a WNT signaling pathway activator, SB- 216763, on the adipocytogenesis and osteocytogenesis of human bone marrow stromal cells （hBMSCs） in vitro. Methods hBMSCs were isolated and cultured from 3 Cases of femoral .head specimens. Upon 60% confluence of hBMSCs, medium was changed to DMEM containing 5 μmol/L SB-216763. After 24 h, the expression of β-catenin was detected by using immunocytochemistry. Methyl thiazol tetrazolium （MTT） assay was performed to analyze the proliferation of hBMSCs after the cells were cultured in 96-well plate with 5 μmol/L SB-216763 for 72 h. Upon confluence of hBMSCs, medium was changed to DMEM containing adipocytogenic or osteocytogenic Supplements in the presence or absence of 5 μmol/L SB-216763. After 10 days, the adipocytogenic cultures were stained with Oil Red-O and the number of Oil Red-O positive cells was counted. For osteocytogenic cultures, the ALP activity was evaluated after 7 days. Results SB- 216763 treatment produced more nuclear expression positive cells （30.2 ± 2.7 ） than the control group （ 13.3 ± 2. 1 ） （P 〈 0. 01 ）, and stimulated the proliferation of hBMSCs determined by MTT assay （ P 〈 0. 01 ）. Generation of Oil Red-O-positive cells was inhibited significantly by SB-216763 （27.4 ± 3.2 vs. 8.4 ± 2. 1,P 〈 0. 01）. ALP activity was inhibited by SB-216763 in hBMSCs under osteocytogenesis （P 〈 0. 01 ）. Conclusion The WNT signaling pathway activator, SB-216763 stimulates proliferation of hBM- SCs, and inhibits both adipocytogenesis and osteocytogenesis of hBMSCs.