Predictive Value of Serum Cholic Acid and Lithocholic Acid for the Diagnosis in an Intrahepatic Cholestasis of Pregnancy Population with High Levels of Total Bile Acids and the Correlation with Placental Hypoxia-Inducible Factor-1α

Serum placental growth factor, total cholesterol, and triglycerides for prediction of intrahepatic cholestasis of pregnancy

This study aims to investigate the predictive values of serum placental growth factor (PIGF), total cholesterol (TC), and triglycerides (TG) in the context of intrahepatic cholestasis of pregnancy (ICP). This retrospective case control study recruited pregnant women from January 2021 to December 2021 at the Maternal and Child Health Hospital of Hunan Province, encompassing pregnant women diagnosed with ICP and those with unremarkable prenatal examinations. A total of 433 pregnant women were included, among whom 167 were diagnosed with ICP after 24 weeks of pregnancy. Patients with ICP exhibited an average age of 31.30 ± 4.54 years and an average pregnancy week at delivery of 37.63 ± 1.45 weeks. Multivariable regression analysis showed that the pregnancy week at delivery (OR = 0.823, 95% CI: 0.769-0.879, P < .001), PIGF (OR = 0.994, 95% CI: 0.992-0.996, P < .001), TC (OR = 1.955, 95% CI: 1.586-2.409, P < .001), and TG (OR = 3.786, 95% CI: 2.655-5.399, P < .001) were independent risk factors for ICP. The area under the curve values for PIGF, TC, and TG in predicting ICP were 0.858 (95% CI: 0.822-0.893), 0.721 (95% CI: 0.670-0.772), and 0.830 (95% CI: 0.788-0.871), respectively. However, their combination yielded an area under the curve value of 0.922 (95% CI: 0.898-0.946). The composite assessment of PIGF, TC, and TG demonstrates potential efficacy in predicting ICP among pregnant women.

Cholic acid exposure during late pregnancy causes placental dysfunction and fetal growth restriction by reactive oxygen species-mediated activation of placental GCN2/eIF2α pathway

Epidemiological studies suggest that fetal growth restriction (FGR) caused by gestational cholestasis is associated with elevated serum cholic acid (CA). Here, we explore the mechanism by which CA induces FGR. Pregnant mice except controls were orally administered with CA daily from gestational day 13 (GD13) to GD17. Results found that CA exposure decreased fetal weight and crown-rump length, and increased the incidence of FGR in a dose-dependent manner. Furthermore, CA caused placental glucocorticoid (GC) barrier dysfunction via down-regulating the protein but not the mRNA level of placental 11β-Hydroxysteroid dehydrogenase-2 (11β-HSD2). Additionally, CA activated placental GCN2/eIF2α pathway. GCN2iB, an inhibitor of GCN2, significantly inhibited CA-induced down-regulation of 11β-HSD2 protein. We further found that CA caused excessive reactive oxygen species (ROS) production and oxidative stress in mouse placentas and human trophoblasts. NAC significantly rescued CA-induced placental barrier dysfunction by inhibiting activation of GCN2/eIF2α pathway and subsequent down-regulation of 11β-HSD2 protein in placental trophoblasts. Importantly, NAC rescued CA-induced FGR in mice. Overall, our results suggest that CA exposure during late pregnancy induces placental GC barrier dysfunction and subsequent FGR may be via ROS-mediated placental GCN2/eIF2α activation. This study provides valuable insight for understanding the mechanism of cholestasis-induced placental dysfunction and subsequent FGR.