Fig. 3.

Effects of calcium channel blockers on cardiomyocyte TXNIP expression. H9C2 cardiomyocytes were incubated at 25 mM glucose and treated with the designated doses of verapamil for 24 h. A: dose-dependent decrease in TXNIP protein levels in response to verapamil as measured by immunoblotting. One representative of 2 independent experiments is shown. B: dose-dependent decrease in TXNIP transcription in response to verapamil as assessed by transfection studies using the human TXNIP reporter construct. Bars represent %transcriptional activity of the human TXNIP promoter as measured by luciferase activity. Means ± SE of 3 independent experiments performed in triplicates are shown. C: H9C2 cardiomyocytes were treated with diltiazem for 24 h and TXNIP protein levels assessed by immunoblotting. Means ± SE of 4 independent experiments are shown.