Hypoxia Alters the Expression of Dipeptidyl Peptidase 4 and Induces Developmental Remodeling of Human Preadipocytes

Figure 5

The effect of insulin on DPP4 expression and activity in human preadipocytes. (a) Human preadipocytes cultured for 2 days under normoxic (18% pO₂) and hypoxic (1% pO₂) conditions were treated for 30 min with 100 nM insulin (black bars). Control cells were treated with vehicle only for 30 min (white bars). Subsequently, the cells were immunolabeled with an antibody against DPP4 and imaged on a confocal microscope. The expression density of immunolabeled DPP4 was analyzed. Data are presented as means ± SE. Numbers denote the number of cells analyzed. The conditioned media were collected from cells treated for 30 min with insulin (Ins) and the protein concentration (b) and protease activity (c) of DPP4 were analyzed. Data are normalized to the number of cells in the sample and presented as means ± SE. Asterisks denote statistically significant differences compared with controls treated with vehicle only, as denoted (; ; ; ANOVA).

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