Berberine inhibits osteogenic differentiation of aortic valve interstitial cells by interfering Smad1/5/8 and NF-κB pathways

Aims: Calcified aortic valve disease (CAVD) is a cardiovascular disease with increasing morbidity and mortality. The pathogenetic cellular mechanism is the phenotypic transition of aortic valve interstitial cells (VICs). Here, we explored the effect of berberine (BBR) on the phenotypic transition of VICs and elucidated the underlying molecular mechanisms, providing a theoretical basis in finding novel clinical treatments for CAVD.Methods and results: Calcific aortic valves and normal controls were collected for western blot and the results demonstrated that osteogenic and inflammatory markers were significantly up-regulated in calcific aortic valves. BBR inhibited inflammation and osteogenic differentiation of VICs under osteogenic conditions, as well as alkaline phosphatase activity and calcified nodule formation. Mechanistically, BBR could inhibit the activation of Smad1/5/8 and NF-Kappa B pathways under OM conditions. LDN193189 and BAY11-7082, the inhibitor of Smad1/5/ 8 and NF-Kappa B respectively, were added for further verification. Similarly, the osteogenic and fibrotic markers of VICs induced by osteogenic induction medium were decreased by LDN193189 and BAY11-7082. Western blot was used to examine upstream receptors of Smad1/5/8, the results showed that BBR inhibited the activation of Smad1/5/8 by downregulating ALK2 and ALK3.Conclusion: BBR decreased the inflammatory factors and suppressed the osteogenic differentiation of VICs, which might be associated with the inhibition of Smad1/5/8 and NF-Kappa B signaling pathways.