Salvianolic acid B stimulates osteogenesis in dexamethasone-treated zebrafish larvae

Abstract

Aim: Our previous studies show that salvianolic acid B (Sal B) promotes osteoblast differentiation and matrix mineralization. In this study, we evaluated the protective effects of Sal B on the osteogenesis in dexamethasone (Dex)-treated larval zebrafish, and elucidated the underlying mechanisms. Methods: At 3 d post fertilization, wild-type AB zebrafish larvae or bone transgenic tg (sp7:egfp) zebrafish larvae were exposed to Sal B, Dex, or a mixture of Dex+Sal B for 6 d. Bone mineralization in AB strain larval zebrafish was assessed with alizarin red staining, and osteoblast differentiation in tg (sp7:egfp) larval zebrafish was examined with fluorescence scanning. The expression of osteoblastspecific genes in the larvae was detected using qRT-PCR assay. The levels of oxidative stress markers (ROS and MDA) in the larvae were also measured. Results: Exposure to Dex (5-20 μmol/L) dose-dependently decreased the bone mineralization area and integral optical density (IOD) in wild-type AB zebrafish larvae and the osteoblast fluorescence area and IOD in tg (sp7:egfp) zebrafish larvae. Exposure to Dex (10 μmol/L) significantly reduced the expression of osteoblast-specific genes, including runx2a, osteocalcin (OC), alkaline phosphatase (ALP) and osterix (sp7), and increased the accumulation of ROS and MDA in the larvae. Co-exposure to Sal B (0.2-2 μmol/L) dosedependently increased the bone mineralization area and IOD in AB zebafish larvae and osteoblast fluorescence in tg (sp7:egfp) zebrafish larvae. Co-exposure to Sal B (2 μmol/L) significantly attenuated deleterious alterations in bony tissue and oxidative stress in both Dex-treated AB zebafish larvae and tg (sp7:egfp) zebrafish larvae. Conclusion: Sal B stimulates bone formation and rescues GC-caused inhibition on osteogenesis in larval zebrafish by counteracting oxidative stress and increasing the expression of osteoblast-specific genes. Thus, Sal B may have protective effects on bone loss trigged by GC.

Immune Suppressive and Bone Inhibitory Effects of Prednisolone in Growing and Regenerating Zebrafish Tissues

“…C , D ; 63% ± 14% in prednisolone versus 100% ± 8% in DMSO). These results are in agreement with previous reports, and clearly indicate glucocorticoid‐induced inhibition of bone formation during ontogeny.…”

“…In growing larvae and homeostatic adult fins, prednisolone treatment reduced the presence of mineralized bone matrix. This is in line with reports in rodent in vivo and in vitro models of glucocorticoid action on bone, and corresponds to recently published results in zebrafish larvae and scales . However, as μCT analyses showed, bone volume of endoskeletal bones, in particular of the spine, is not affected by prednisolone treatment.…”

Resveratrol Ameliorates Glucocorticoid-Induced Bone Damage in a Zebrafish Model

“…A DFC 310 FX camera (Leica, Germany) was used to capture the fluorescent images (100×). All images were obtained using the same light intensity and exposure settings (Luo et al., 2016). The sample size of each group was n = 15.…”

Screening in larval zebrafish reveals tissue-specific distributions of fifteen fluorescent compounds

“…To test whether purpurin can be used to help identify developmental bone defects in zebrafish larvae, we treated 2–6 dpf larvae with 20 μM dexamethasone to interrupt bone calcification as previously reported ( Luo et al, 2016 ). Compared with the control group, dexamethasone-treated larvae displayed severe defects in bone development, with significantly delayed calcification in the anterior vertebral column, which can be clearly distinguished via either purpurin or calcein staining ( Fig.…”