IL-33 Signaling Inhibition Leads to a Preeclampsia-Like Phenotype in Pregnant Rats.

Area of Science:

• Immunology
• Reproductive Medicine
• Vascular Biology

Background:

• Preeclampsia (PE) is a pregnancy disorder causing maternal and fetal mortality, characterized by vascular dysfunction, oxidative stress, and inflammation.
• Aberrant immune responses are implicated in PE pathophysiology, with the IL-33 signaling pathway being a potential mediator.
• Current treatments for PE are limited to delivery, highlighting the need for understanding its underlying mechanisms.

Purpose of the Study:

• To investigate the impact of inhibiting IL-33 signaling on key immune cell populations (cytotoxic natural killer cells [cNK], T helper 17 cells [T_H17], and regulatory T cells [T_Reg]).
• To assess the effects of IL-33 inhibition on vascular function, specifically maternal blood pressure and uterine artery resistance.
• To examine the influence of IL-33 signaling on oxidative stress markers in the kidneys and placenta.

Main Methods:

• IL-33 signaling was inhibited using recombinant ST2 (a decoy receptor) and a neutralizing antibody.
• Maternal blood pressure and uterine artery resistance index were monitored.
• Levels of oxidative stress, cytokine profiles, and pre-proendothelin-1 were measured in renal and placental tissues.

Main Results:

• Inhibition of IL-33 signaling led to increased maternal blood pressure and uterine artery resistance.
• Placental and renal oxidative stress markers were elevated following IL-33 inhibition.
• Immune cell populations shifted, with increased cNK and T_H17 cells and decreased T_Reg cells in both placental and circulation.

Conclusions:

• IL-33 signaling plays a critical role in regulating vascular function and maternal blood pressure during pregnancy.
• The IL-33 pathway influences innate and adaptive immune responses relevant to PE pathophysiology.
• Targeting the IL-33 signaling pathway presents a potential therapeutic strategy for preeclampsia management.