Effects and Mechanism of Berberine on the Dexamethasone-Induced Injury of Human Tendon Cells.

OBJECTIVE

To investigate the effects of berberine (Berb) on dexamethasone- (Dex-) induced injury of human tendon cells and its potential mechanism.

METHODS

CCK-8 assay was used to explore the appropriate concentration of Dex-induced injury of tendon cells and the doses of Berb attenuates Dex cytotoxicity; cell wound healing assay was used to detect the effects ( < 0.05) of Berb and Dex on the migration ability of tendon cells; flow cytometry was used to measure cell apoptosis; DCF DA fluorescent probe was used to measure the ROS activity of cells. Western blotting was used to detect the expression of phenotype related factors including smooth muscle actin (SMA-), type I collagen (Col I), col III, apoptosis-related factors, caspase-3, cleaved caspase-3, caspase-9, cleaved caspase-9, and PI3K/AKT.

RESULTS

CCK-8 assay showed that 1-100 M Dex significantly inhibited the proliferation of tendon cells in a concentration-dependent manner ( < 0.05), where the inhibitory effect of 100 M Dex was most significant ( < 0.005), and the pretreatment of 150, 200 M Berb could reverse those inhibitions (all < 0.05). Compared with the control group, Dex significantly inhibited cell migration ( < 0.05), while Berb pretreatment could enhance cell migration ( < 0.05). Flow cytometry and ROS assay showed that Dex could induce apoptosis and oxidative stress response of tendon cells (all < 0.05), while Berb could reverse those responses ( < 0.05). Western blot showed that Dex could inhibit the expression of the col I and III as well as -SMA (all < 0.05) and enhance the expression of apoptosis-related factors including cleaved caspase-3 and cleaved caspase-9 (all < 0.05). Besides, Dex could also inhibit the activation of the PI3K/AKT signaling pathway (all < 0.05), thus affecting cell function, while Berb treatment significantly reversed the expression of those above proteins (all < 0.05).

CONCLUSION

Berb attenuated DEX induced reduction of proliferation and migration, oxidative stress, and apoptosis of tendon cells by activating the PI3K/AKT signaling pathway and regulated the expression of phenotype related biomarkers in tendon cells. However, further studies are still needed to clarify the protective effects of Berb in vivo.