Hypoxia-inducible factor alpha (HIF-1α) translocation after differentiation of monocytes to macrophages and co-culture with endothelial cells. (A, B) Detection of HIF-1α, Lamin B and β-actin in monocyte or hMDM nuclear (NF+) and cytosolic (NF-) cell fractions using immunoblot. (A) Protein lysates were acquired after incubation of human monocytes and hMDM for 5 h under hypoxia. Differentiation of monocytes to macrophages leads to HIF-1α translocation into the nucleus. (B) Monocyte protein lysates were acquired after incubation of human monocytes on human endothelial cells (HMEC-1, human microvascular endothelial cells) coated well plates for 5 h under normoxia and under hypoxia. Co-culture of monocytes with endothelial cells is not sufficient for the translocation of HIF-1α.