Figure 1
Exposure of term cytotrophoblast cells to low oxygen increases steady state levels of HLA-G mRNAs. Cytotrophoblast cells harvested from a term placenta using gradient centrifugation and purified by magnetic bead technology were >98% cytokeratin-7 positive. The cells were cultured for 72 hr under ambient (20% O2) and two hypoxic (8%, 2%) conditions. RT-PCR experiments were conducted using mRNA-specific primers. The results were analyzed using scanning densitometer against a stable message (β2m). Note that the abundance of transcripts encoding HLA-G1, -G2, -G5 (sHLA-G1), and -G6 (sHLA-G2) were inversely related to levels of O2. Under 2% O2, mRNAs encoding HLA-G1 and -G5 were more profoundly enhanced (×7, ×4, respectively) than those encoding HLA-G2 and -G6 (×2, ×2, respectively).