Department of Orthopaedics Surgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China; Department of Orthopedics, The First People's Hospital of Zunyi, Zunyi 563000, PR China.
Department of Oncology, Affiliated Hospital of Zunyi Medical College, Zunyi 563000, PR China.
Biomed Pharmacother. 2018 Sep;105:753-757. doi: 10.1016/j.biopha.2018.04.185. Epub 2018 Jun 14.
Adipose derived stem cells (ADSCs) could undergo osteogenesis via focal adhesion kinase (FAK) and bone morphogenetic protein (BMP) 9 signals, both of which could affect Wnt-β-catenin signal, a signal pathway closely related to ADSCs osteogenesis. It's still enigma whether FAK and BMP-9 contribute to osteogenesis. Here, we examined the effect of FAK on BMP9-inducedosteogenic differentiation, unveiled the possible molecular mechanism underling this process.
In the present study, ADSCs were isolated and purified, and cells of passage 3 underwent virus mediated transfection to prepare ADSCs with stable FAK shRNA expression. Cell viability and migration were detected by MTT and transwell assay, respectively. Expression of osteogenic gene, phosphorylation of FAK and GSK were detected by western blot. Osteogenic potential was evaluated by activity of alkaline phosphatase (ALP) and calcium deposition by ALP staining and Alizarin Red S staining.
BMP-9 administration promoted ADSCs osteogenesis. Knocking down FAK attenuated this process, inhibited osteogenic proteins expression through Wnt-β-catenin signal. BMP-9 also triggered ADSCs proliferation and migration, and shFAK antagonized such effects too. Although Wnt signal is affected by FAK shRNA, Smad signal remains intact in ADSCs with shFAK.
FAK and BMP-9 could cross talk on Wnt signal pathway and promote ADSCs osteogenesis. FAK could participate in BMP-9 induced ADSCs osteogenesis via Wnt signal pathway other than Smads signals (see in graph).
脂肪来源的干细胞（ADSCs）可通过黏着斑激酶（FAK）和骨形态发生蛋白（BMP）9 信号转导途径向成骨细胞分化，这两种信号都可以影响与 ADSCs 成骨密切相关的 Wnt-β-catenin 信号。FAK 和 BMP-9 是否促进成骨仍不清楚。本研究旨在探讨 FAK 对 BMP9 诱导的成骨分化的影响，并揭示其可能的分子机制。
本研究分离并纯化 ADSCs，第 3 代细胞通过病毒介导的转染制备稳定表达 FAK shRNA 的 ADSCs。MTT 和 Transwell 检测细胞活力和迁移。Western blot 检测成骨基因表达、FAK 和 GSK 磷酸化。碱性磷酸酶（ALP）活性和钙沉积通过 ALP 染色和茜素红 S 染色评估成骨潜能。
BMP-9 处理促进 ADSCs 成骨。敲低 FAK 减弱了这一过程，通过 Wnt-β-catenin 信号抑制成骨蛋白的表达。BMP-9 还能促进 ADSCs 的增殖和迁移，而 shFAK 则拮抗了这种作用。虽然 Wnt 信号受到 shFAK 的影响，但 Smad 信号在 shFAK 的 ADSCs 中仍然完整。
FAK 和 BMP-9 可通过 Wnt 信号通路相互作用，促进 ADSCs 成骨。FAK 可通过 Wnt 信号通路而不是 Smads 信号参与 BMP-9 诱导的 ADSCs 成骨（见图）。
