We specifically measured hENT1 expression [mRNA, protein abundance, SLC29A1 (for hENT1) promoter activity] and activity (adenosine transport kinetics) and the role of IR-A/IR-B expression and signaling [total and phosphorylated 42 and 44 kDa mitogen-activated protein kinases (p44/42(mapk)) and Akt] in IR-A, IR-B, and IR-A/B knockdown HUVECs from normal (n = 33) or GDM (n = 33) pregnancies.
Cells from GDM exhibited increased insulin receptor A isoform expression in addition to the reported NO-dependent inhibition of hENT1-adenosine transport and SLC29A1 reporter repression, and increased extracellular concentration of adenosine and NO synthase activity.