Biomaterials and Live Cell Imaging Institute, School of Metallurgy and Materials Engineering, Chongqing University of Science and technology, Chongqing, People's Republic of China.
PLoS One. 2012;7(8):e42709. doi: 10.1371/journal.pone.0042709. Epub 2012 Aug 10.
Non-receptor protein kinases FAK and Src play crucial roles in regulating cellular adhesions, growth, migration and differentiation. However, it remains unclear how the activity of FAK and Src is regulated during the differentiation process from mesenchymal stem cells (MSCs) to bone cells. In this study, we used genetically encoded FAK and Src biosensors based on fluorescence resonance energy transfer (FRET) to monitor the FAK and Src activity in live cells during the differentiation process. The results revealed that the FAK activity increased after the induction of differentiation, which peaked around 20-27 days after induction. Meanwhile, the Src activity decreased continuously for 27 days after induction. Therefore, the results showed significant and differential changes of FAK and Src activity upon induction. This opposite trend between FAK and Src activation suggests novel and un-coupled Src/FAK functions during the osteoblastic differentiation process. These results should provide important information for the biochemical signals during the differentiation process of stem cells toward bone cells, which will advance our understanding of bone repair and tissue engineering.
非受体蛋白激酶 FAK 和 Src 在调节细胞黏附、生长、迁移和分化方面发挥着至关重要的作用。然而，FAK 和 Src 的活性在间充质干细胞 (MSCs) 向成骨细胞分化过程中是如何被调控的，目前尚不清楚。在这项研究中，我们使用基于荧光共振能量转移 (FRET) 的基因编码 FAK 和 Src 生物传感器来监测活细胞在分化过程中 FAK 和 Src 的活性。结果表明，诱导分化后 FAK 活性增加，在诱导后 20-27 天达到峰值。同时，Src 的活性在诱导后连续 27 天持续下降。因此，结果表明 FAK 和 Src 活性在诱导时发生了显著的差异变化。FAK 和 Src 激活之间的这种相反趋势表明，在成骨细胞分化过程中 Src/FAK 具有新的、不偶联的功能。这些结果应该为干细胞向成骨细胞分化过程中的生化信号提供重要信息，从而增进我们对骨修复和组织工程的理解。
