[Upregulated Notch1 expression promotes bone morphogenetic protein-2/4 expression of calcified human heart valve...

To observe the protein expression of Notch1 in the cultured calcified human heart valve interstitial cells (hVICs) in vitro and related mechanisms.

hVICs were divided into two groups: control hVICs were cultured in conventional media for 14 days and calcified hVICs were cultured with calcification inducers: β-glycerophosphate (500 μl), ascorbic acid (200 μl), dexamethasone(100 μl) for 7 days. The calcified hVICs were further divided into calcified hVICs group and inhibited calcified hVICs by adding specific Notch1 inhibitor DAPT (50 μmol/L(4 μl/hole))groups and cultured for another 7 days. Inflammatory response of all groups were induced by lipopolysaccharide (LPS) for 8 to 12 hours. Western blot was used to detect the protein expression of Notch1, phosphorylation nuclear transcription factor κB (p-NF-κB), bone morphogenetic protein-2/4(BMP-2/4). ELISA was applied to detect the content of BMP-2 secretion of the groups. Von Kossa staining was used to observe of cellular calcification.

(1)Von Kossa staining is positive in the induced calcification group, the expression of Notch1, p-NF-κB, BMP-2 and BMP-4 is significantly higher in the induced calcification group than in the control group (all P<0.05). The expression of BMP-2 is significantly higher in the induced calcification group than in control group ((88.23±3.28) pg/ml vs. (25.41±3.68) pg/ml, P=0.02). (2) After treatment with DAPT, the calcification and the expression of Notch1, p-NF-κB, BMP-2 and BMP-4 were significantly decreased compared to calcification group (all P<0.05). The expression of BMP-2 is (26.74±4.62) pg/ml in the calcification inhibition group and (80.41±2.96) pg/ml in calcified control group (P=0.02).

Upregulated Notch 1 expression promotes BMP-2/4 secretion in LPS stimulated hVICs, and contributes to osteogenic changes in hVICs. Inhibiting Notch1 can decrease the BMP-2/4 secretion and calcification in hVICs, which may serve as a novel therapeutic option for treating calcific valve disease.