Immunohistochemistry (IHC)
The human and rat placental tissue sections were deparaffinized in xylene and rehydrated through a graded series of ethanol solutions. Antigen retrieval was performed by immersing the sections in 10 mM citrate buffer (pH 6.0) and heating them in a pressure cooker for 15 min. Endogenous peroxidase activity was quenched by incubating the sections in 3% hydrogen peroxide solution for 10 min. Subsequently, the sections were blocked with 5% inactivated goat serum for 1 h at room temperature. The sections were then incubated overnight at 4°C with the following primary antibodies: TP53BP2 (1:5 00, Abcam, Cambridge, USA), LC3B (1:200, Abcam, Cambridge, USA), and p62 (1:200, Abcam, Cambridge, USA). After being washed with PBS, the sections were incubated with the secondary antibody for 2 h at room temperature. Immunoreactivity was visualized by the addition of 3,3’-diaminobenzidine (DAB) substrate solution. The sections were counterstained with Harris hematoxylin for 30 s to visualize the cell nuclei. Finally, the sections were dehydrated through ethanol and xylene, and images were captured via an optical microscope.