摘要目的探讨血清素对成骨细胞Ⅰ型胶原蛋白合成的影响。方法用不同浓度（50、100、200和400 ng／L）的血清素处理人成骨细胞，即时定量PCR（ RT-PCR）观察成骨细胞中Ⅰ型胶原蛋白和赖氨酰氧化酶（ LOX）含量的变化。用LOX siRNA干扰LOX蛋白的表达后，用Western blot法检测干扰效果，用酶联免疫吸附实验检测Ⅰ型胶原蛋白含量的变化。用RT-PCR检测血清素处理成骨细胞后Smad2蛋白、Smad3蛋白表达量的变化和Smad3基因敲除对LOX蛋白表达的影响。结果血清素上调成骨细胞中Ⅰ型胶原蛋白和LOX的表达水平，LOX siRNA可显著抑制Ⅰ型胶原蛋白的表达。此外，血清素上调了成骨细胞中Smad2蛋白和Smad3蛋白的表达，干扰Smad3基因的转录，抑制LOX蛋白的表达。结论血清素通过Smad信号通路上调LOX的表达，并促进成骨细胞Ⅰ型胶原蛋白的合成。

abstractsObjective To explore the mechanism of serotonin-promoted osteoblast differentiation.Methods Expression levels of collagen Ⅰand lysyl oxidase ( LOX) in osteoblast were measured by RT-PCR after treated by (50, 100, 200 and 400 ng/L) serotonin.LOX siRNA effect was measured by Western blot, and protein levels of collagen Ⅰ were determined by ELISA after treated by serotonin.Expression levels of Smad2 and Smad3 in osteoblasts were also measured by RT-PCR after treated by serotonin.Moreover , expression levels of LOX were measured by RT-PCR after Smad3 was knockout.Results Serotonin promoted collagenⅠ and LOX expression.The expression level of collagenⅠ was significantly decreased by LOX siRNA.Furthermore , serotonin up-regulated the expression of Smad 2 and Smad3 in osteoblasts , and the expression level of LOX was inhibited by Smad 3 siRNA.Conclusion Serotonin promoted collagenⅠexpression by activating Smads signaling pathway and up-regulating the LOX expression.