Elevated Placental Adenosine Signaling Contributes to the Pathogenesis of Preeclampsia
Background—Preeclampsia (PE) is a prevalent hypertensive disorder of pregnancy and a leading cause of maternal and neonatal morbidity and mortality worldwide. This pathogenic condition is speculated to be due to placental abnormalities that contribute to the maternal syndrome. However, the specific factors and signaling pathways leading to impaired placentas and maternal disease development remain elusive.
Methods and Results—By using two independent animal models of PE—1) genetically-engineered pregnant mice with elevated adenosine exclusively in placentas, and 2) a pathogenic autoantibody-induced PE mouse model—we demonstrated here that chronically elevated placental adenosine was sufficient to induce hallmark features of PE including hypertension, proteinuria, small fetuses, and impaired placental vasculature. Genetic and pharmacologic approaches revealed that elevated placental adenosine coupled with excessive A2B adenosine receptor (ADORA2B) signaling contributed to the development of these features of PE. Mechanistically, we provided both human and mouse evidence that elevated placental CD73 is a key enzyme causing increased placental adenosine, thereby contributing to PE.
Conclusions—We determined that elevated placental adenosine signaling is a previously unrecognized pathogenic factor for PE. Moreover, our findings revealed the molecular basis underlying the elevation of placental adenosine and the detrimental role of excess placental adenosine in the pathophysiology of PE, and, thereby highlight novel therapeutic targets.
- Received October 10, 2014.
- Revision received November 20, 2014.
- Accepted December 4, 2014.