摘要目的 探讨15 Hz、1 mT电磁场(EMFs)对骨髓间充质干细胞成软骨分化指标聚集蛋白聚糖(Age)Ⅰ、Ⅱ型胶原和Sox9等的影响及其机制.方法体外培养SD大鼠骨髓间充质干细胞,取第3代细胞,用15 Hz、1 mT EMFs刺激,8 h/d.采用半定量逆转录聚合酶链反应(RT-PCR)法检测甲状旁腺激素受体相关肽(PTHrp)、Agc Ⅰ、Ⅱ型胶原和Sox9等mRNA的表达,用Western Blot检测Ⅱ型胶原蛋白的表达.加入解蛋白激酶A(PKA)抑制剂H-89和蛋白激酶C(PKC)抑制剂Go-6976,并再次用RT-PCR法和Western Blot观察EMFs对Agc Ⅰ、Ⅱ型胶原和Sox9等mRNA的表达的影响.结果 EMFs促进骨髓间充质干细胞PTHrp、Agc Ⅰ、Ⅱ型胶原和Sox9等mRNA的表达,促进Ⅱ型胶原蛋白的表达;在加入H-89(10 μm)和G0-6976(12μm)后EMFs的这种促进Agc Ⅰ、Ⅱ型胶原的效应就明显减弱,但Sox9的表达不受影响.结论 EMFs促进骨髓间充质干细胞成软骨分化指标AgcⅠ、Ⅱ型胶原和Sox9等mRNA的表达,这种促进作用同PKA和PKC通路有联系.

abstractsObjective To study the expressions of aggrecan (Agc) Ⅰ and Ⅱ collagen and Sox9 by bone mar-row mesenchymal stem cells exposed to electromagnetic fields (EMFs) and it's mechanisms involved. Methods Bone marrow mesenchymal stem cells were isolated from Sprague-Dawley rats and cultured in vitro. The third passage cells were harvested and exposed to 15 Hz 1 mT EMFs for 8 h/d. The semi-quantitative reverse transcription-polyme-rase chain reaction (RT-PCR) technique was used to measure parathyroid hormon receptor related peptide (PTHrp) ,Agc Ⅰ and Ⅱ collagen and Sox9 mRNA. Western blotting was used to measure type Ⅱ collagen expression. After the inhibitor of protein kinase A (PKA) H-89 and the inhibitor of protein kinase C (PKC) Go-6976 ( 12 μm) were added, the effects of EMFs on Agc Ⅰ and Ⅱ collagen and Sox9 mRNA expressions were measured again by using RT-PCR, and Western blotting technique. Results The EMFs induced significant increase of mRNA expressions of PTHrp, Agc Ⅰ and Ⅱ collagen and Sox9 in comparison to the controls, and promoted type Ⅱ collagen protein expres-sion. The Agc Ⅰ and Ⅱ collagen expressions decreased after PKA pathway inhibitor H-89 and PKC inhibitor Go-6976 were added, but the mRNA expression of Sox9 was not affected. Conclusion This study shows 15Hz 1mT EMFs can promote mRNA expressions of Agc Ⅰ and Ⅱ collagan and Sox9 of cbondrogenesis differentiation markers in bone marrow mesenchymal stem cells. The effect is correlated with PKA and PKC pathways.