Ivabradine inhibits SDF-1-induced PI 3-kinase activity and phosphorylation of AKT. (a) Human CD4-positive cells were pretreated with ivabradine in different concentrations for 15 minutes before cells were stimulated with SDF-1 (100 ng/mL). After 5 minutes, PI 3-kinase activity assay was performed. Specific dots are labelled with an arrow (PIP). Three independent experiments showed similar results. (b) SDF-1 leads to phosphorylation of AKT. Isolated CD4-positive lymphocytes were pretreated with ivabradine in different concentrations indicated before stimulation with 100 ng/mL SDF-1 for 10 min. Total lysates were analyzed by immunoblotting employing antibodies against phospho-AKT. Equal loading of intact protein was confirmed by staining for GAPDH. Densitometric analysis were performed of 3 independent experiments. Data are expressed as p-AKT normalized to GAPDH. Bars represent mean ± SD. * compared with SDF-1-stimulated cells; .
