Brucine inhibits bone metastasis of breast cancer cells by suppressing Jagged1/Notch1 signaling pathways.

OBJECTIVE: To examine the effects of brucine on the invasion, migration and bone resorption of receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclastogenesis. METHODS: The osteoclastogenesis model was builded by co-culturing human breast tumor MDA-MB-231 and mouse RAW264.7 macrophages cells. RANKL (50 ng/mL) and macrophage-colony stimulating factor (50 ng/mL) were added to this system, followed by treatment with brucine (0.02, 0.04 and 0.08 mmol/L), or 10 µmol/L zoledronic acid as positive control. The migration and bone resorption were measured by transwell assay and in vitro bone resorption assay. The protein expressions of Jagged1 and Notch1 were investigated by Western blot. The expressions of transforming growth factor-ß1 (TGF-ß1), nuclear factor-kappa B (NF-κB) and Hes1 were determined by enzyme-linked immunosorbent assay. RESULTS: Compared with the model group, brucine led to a dose-dependent decrease on migration of MDA-MB-231 cells, inhibited RANKL-induced osteoclastogenesis and bone resorption of RAW264.7 cells (P<0.01). Furthermore, brucine decreased the protein levels of Jagged1 and Notch1 in MDA-MB-231 cells and RAW264.7 cells co-cultured system as well as the expressions of TGF-ß1, NF-κB and Hes1 (P<0.05 or P<0.01). CONCLUSION: Brucine may inhibit osteoclastogenesis by suppressing Jagged1/Notch1 signaling pathways.

Astragalus injection attenuates bleomycin-induced pulmonary fibrosis via down-regulating Jagged1/Notch1 in lungs.

OBJECTIVES: Inhibition of Notch signalling is a potential therapeutic strategy for pulmonary fibrosis. This study was designed to investigate the antifibrosis effects and possible mechanism of astragalus injection (AI) on bleomycin (BLM)-induced pulmonary fibrosis in rats. METHODS: Pulmonary fibrosis was induced by intratracheal instillation of bleomycin (5 mg/kg) in male SD rats. All rats received daily intraperitoneally administration of dexamethasone (DEX, 3 mg/kg), astragalus injection (AI, 8 g/kg) or saline 1 day after bleomycin instillation daily for 28 days. Histological changes in the lung were evaluated by haematoxylin and eosin and Masson's trichrome staining. The expression of α-smooth muscle protein (α-SMA) was assayed by immunohistochemical (IHC). The mRNA and protein level of Jagged1, Notch1 and transforming growth factor-ß1 (TGF-ß1) was analysed by qPCR and Western blot. KEY FINDINGS: BLM-induced severe alveolitis and pulmonary fibrosis; together with significant elevation of α-SMA, TGF-ß1, Jagged1 and Notch1. Astragalus injection (AI, 8 g/kg) administration notably attenuated the degree of alveolitis and lung fibrosis, and markedly reduced the elevated levels of α-SMA, TGF-ß1, Jagged1 and Notch1 in lungs. CONCLUSIONS: Astragalus injection (AI, 8 g/kg) may exert protective effects on bleomycin-induced pulmonary fibrosis via downregulating Jagged1/Notch1 in lung.