SWATH Proteomics analysis of placental tissue with intrahepatic cholestasis of pregnancy_part2

Introduction: Intrahepatic cholestasis of pregnancy (ICP) usually occurs in the second and third trimesters. The disease's etiology and diagnostic criteria are currently unknown. Based on a sequence window to obtain all theoretical fragment ions (SWATH) proteomic approach, this study sought to identify potential proteins in placental tissue that may be involved in the pathogenesis of ICP and adverse fetal pregnancy outcomes.

Methods: The postpartum placental tissue of pregnant women with ICP were chosen as the case group (ICP group) (subdivided into mild ICP group (MICP group) and severe ICP group (SICP group)), and healthy pregnant women were chosen as the control group (CTR). The SWATH analysis combined with liquid chromatography-tandem mass spectrometry (LC-MS) was used to screen the differentially expressed proteins (DEPs) in ICP and CTR groups, and bioinformatics analysis was used to find out the biological process of these differential proteins. 

Results: Proteomic studies showed there were 126 DEPs from pregnant women with ICP and healthy pregnant women. Most of the identified proteins were functionally related to humoral immune response, cell response to lipopolysaccharide, antioxidant activity and heme metabolism. A subsequent examination of placentas from patients with mild and severe ICP revealed 48 proteins that were differentially expressed. Through death domain receptors and fibrinogen complexes, these DEPs primarily regulate extrinsic apoptotic signaling pathways, blood coagulation, and fibrin clot formation. 

Discussion: This preliminary study helps us to understand the changes in the placental proteome of ICP patients, and provides new insights into the pathophysiology of ICP.