Placenta-Derived Secretions Promote Liver Dysfunction, and Hepatic Serum Amyloid A Mediates Kidney Inflammatory Response in a Preeclampsia-like Mouse Model

Preeclampsia (PE) is characterized by maternal hypertension accompanied with multi-organ dysfunction, such as maternal hepatic and renal dysfunction. Abnormal placental conditions may play a key role in regulating maternal organ function by promoting systemic inflammation. This study aimed to test the hypothesis that placenta-derived secretions contribute to hepatic and renal injury through interorgan communication using a PE-like mouse model. Pregnant mice were infused with angiotensin II (Ang II) from gestational day (GD) 12 (GD1 defined as the day of plug detection). Ang II infusion induced maternal hypertension, as well as liver injury (elevated serum amyloid A [SAA] secretion and alanine aminotransferase levels) and kidney injury (tubular damage with KIM-1 protein expression and immune cell infiltration). Treatment with placental-conditioned medium (CM) from Ang II-infused mice, but not from the control mice, stimulated SAA expression in liver cells. On the other hand, the effects of placental-CM from both the control and Ang II groups on kidney tubular cells were comparable. These findings suggest that placenta-derived secretions in the Ang II-induced PE-like phenotype specifically promote excessive SAA production in the liver. Furthermore, SAA administration in pregnant mice did not cause tubular injury but did promote renal immune cell infiltration, indicating that elevated hepatic SAA levels may contribute to maternal kidney inflammation. Taken together, these results suggest the presence of an in vivo organ network involving the placenta, liver, and kidneys during pregnancy, where dysfunction in one organ may exacerbate the pathogenesis of PE.