Astragaloside­IV modulates NGF­induced osteoblast differentiation via the GSK3β/β­catenin signalling pathway.

Astragaloside (AST) is derived from the Chinese herb Astragalus membranaceus, and studies have demonstrated that it promotes differentiation of bone marrow­derived mesenchymal stem cells (BMSCs). To the best of our knowledge, however, the functions of the component AST­IV in osteogenesis have not previously been elucidated. The present study aimed to verify the effects of AST­IV in osteogenesis. First, the proliferation and differentiation status of human BMSCs incubated with AST­IV were analysed and compared with a control (no AST­IV treatment). In order to determine the involvement of the glycogen synthase kinase (GSK)3ß signalling pathway in AST­IV, overexpression and inhibition of GSK3ß was induced during incubation of BMSCs with AST­IV. In order to investigate how neuronal growth factor (NGF) contributes to BMSCs differentiation, BMSCs were co­incubated with an anti­NGF antibody and AST IV, and then levels of osteogenesis markers were assessed. The results demonstrated for the first time that AST­IV contributed to BMSCs differentiation. Furthermore, the GSK3ß/ß­catenin signalling pathway was revealed to be involved in AST­IV­induced osteogenesis; moreover, AST­IV accelerated differentiation by enhancing the expression levels of NGF. In summary, the present study demonstrated that AST­IV promotes BMSCs differentiation, thus providing a potential target for the treatment of osteoporosis.

Astragalus saponin IV promotes osteogenic differentiation of bone marrow mesenchymal stem cells via miR-21/NGF/BMP2/Runx2 pathway.

BACKGROUND: Astragalus saponin IV(AS- IV) extracted from tranditional Chinese medicine Radix Astragali Mongolici, which had been reported to have medicinal properties in treating several types of diseases. This study aimed at investigating the biological functions of AS-IV on bone marrow mesenchymal cells(BMSCs) differentiation, therefore, seeking for a better application of AS-IV on fracture or other orthopedic disorders. METHODS: AS-IV was co-incubated with BMSCs in vitro to testify whether it can influence the proliferation and differentiation of BMSCs. Cell proliferation activity was detected by Cell Counting Kit-8 (CCK-8), while its differentiation promoting capibility was obtained by alkaline phosphatase (ALP) activity assay and Alizarin red S staining. Besides, differentiation protein markers of preosteoblast was detected by western blots. Neuron growth factor antagonists (NGFA) and microRNA-21 (miR-21) inhibitors were co incubated with AS-IV to search the regulatory pathways it activated in BMSCs. RESULTS: AS-IV incubation boosted the proliferation of BMSCs, and accelerated the differentiating direction into preosteoblasts. Runx2, OPN, BMP2, OCN proteins were up regulated after AS- IV treatment. MiR-21/NGF/BMP2/Runx2 pathway can participate the biological effects of AS- IV on BMSCs. CONCLUSION: AS- IV might be used as a therapeutic agent for bone fracture or other orthopedic disorders.