FTIR microscopic study on biomolecular alterations in placental tissues of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder that typically leads to severe pregnancy outcomes. Although genetic, endocrine, and environmental factors are involved in the etiology of ICP, the role of metabolic disorders remains unclear. Here we report an examination of the biomolecular alterations in placental tissues of women with ICP and healthy pregnant women at a molecular level. By integrating FTIR microspectroscopy with advanced multivariate statistical analysis and semiquantitative methods, including PCA, OPLS-DA and peak area ratio calculations, the biomolecular alterations were revealed. Specifically, alterations in lipid conformations and increased lipid acyl chain unsaturation in the ICP group were associated with bile acids participating in the regulation of lipid metabolism. Additionally, a reduction in the relative α-helix content of proteins compared to β-sheet structures was associated with changes in apoptosis-related proteins. Furthermore, the nucleic acid content relative to lipids and proteins was elevated in the ICP group. Our study underscores the potential of FTIR microspectroscopy as a powerful tool for investigating the underlying biochemical mechanisms related to ICP.