Figure 2.

Insulin-like growth factor 1 receptor (IGF1R) glycosylation in the human placenta is reduced by 3-hydroxy-3-methylglutaryl co-enzyme A [HMG-CoA] reductase inhibitors. First trimester placental explants were incubated in the absence or presence of pravastatin (250 nM), cerivastatin (50 nM), tunicamycin (1 μg/ml), castanospermine (5 μg/ml) or deoxymannojirimycin (DMJ; 0.5 mM) for 24 h. IGF1R was immunoprecipitated from the samples using IGF1R specific antibodies (or mouse IgG as a negative control) (A) and its glycosylation status analysed by lectin dot blot (B) using lectins that recognize different glycosylation sites: Phaseolus vulgaris lectin (ePHA) and l-phytohaemagglutinin (lPHA). Both statin treatment and glycosylation inhibitors reduced the levels of IGF1R glycosylation detected by both ePHA and lPHA. Human serum was used as a positive control and specificity of the detection method was confirmed by the absence of positive signal when no lectins were used (streptavidin-horse radish peroxidase [HRP] only). Each image is representative of experiments performed on three individual placentas.