Perinatal Endotoxemia Induces Sustained Hepatic COX-2 Expression through an NFκB-Dependent Mechanism

Sarah McKenna1, Molly Eckman, Andrew Parker

  • 1Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colo., USA.

Insights

Neonatal exposure to endotoxemia causes sustained hepatic macrophage cyclooxygenase-2 (COX-2) expression and NFκB activity, unlike in adults. This robust innate immune response may link to preterm birth complications.

Area of Science:

  • Immunology
  • Neonatal research
  • Infectious disease

Background:

  • Perinatal infections are linked to preterm birth complications.
  • The role of the immature neonatal innate immune response is unclear.

Purpose of the Study:

  • To investigate if the perinatal innate immune response to endotoxemia uniquely patterns cyclooxygenase-2 (COX-2) expression.
  • To determine if this pattern is NFκB-dependent.

Main Methods:

  • Assessed hepatic and pulmonary COX-2 mRNA in perinatal and adult mice after endotoxemia.
  • Measured hepatic NFκB activity via protein degradation and nuclear translocation.
  • Determined hepatic macrophage COX-2 expression and tested NFκB inhibition.

Main Results:

  • Perinatal endotoxemia induced sustained hepatic macrophage COX-2 expression and NFκB activity compared to adults.
  • COX-2 expression in isolated macrophages was sensitive to NFκB inhibition.
  • Inhibition of NFκB in neonatal mice reduced hepatic NFκB activity and COX-2 expression.

Conclusions:

  • Neonatal endotoxemia triggers a sustained hepatic NFκB and COX-2 response, indicating a robust perinatal innate immunity.
  • This sustained response may connect innate immunity to diseases complicating preterm birth.
Abstract