Investigation of expression levels of endoplasmic reticulum stress proteins in unexplained recurrent pregnancy loss

Objective: Recurrent pregnancy losses (RPL) are cytogenetic abnormalities that affect 2-5% of pregnancies. The endoplasmic reticulum (ER) is an important organelle for the maintenance of normal cellular functions and cell survival, responsible for protein and lipid production in the cell. ER stress (ERS) occurs related to the accumulation of misfolded or unfolded proteins in the ER under various conditions. The expression levels of ERS proteins in decidua and chorionic villus during pregnancy and RPL were not known. There was no literature information on the role of ERS proteins in the Unexplained RPL (URPL). We established the hypothesis that "in (URPL), the expression levels of ERS proteins differ in chorionic villi and decidua compared to normal pregnancies". We aimed to determine the localization and expressions of ERS proteins, GRP78 and CHOP, in the decidua and chorion villus samples of the patient with URPL, and to have an idea about the etiology of the disease. Method: Three groups were formed as control endometrium (KE) (n = 6), optional terminated pregnancy (TP) (n = 6) and URPL (n = 6). The decidua and chorion areas of the pregnancy groups were separated under a stereomicroscope. After Tissue follow-up, 5-micron sections were taken. Morphology with HE histological staining and also localization of GRP78 and CHOP proteins with immunohistochemical staining methods were evaluated. Results : CHOP expression was higher in the maternal part of the URPL group compared to the control. Increased GRP78 expression in stromal cells was higher in the URPL group than in the non-pregnant group in a healthy pregnancy. Severe CHOP nuclear staining was also observed in decidual cells in URPL. Both cytoplasmic and nuclear GRP78 and CHOP staining were observed in cytotrophoblast and syncytiotrophoblast cells in chorion samples of TP and URPL patients. Conclusion:As a result of our immunohistochemical evaluation, pregnancy caused ERS in maternal and fetal extraembryonic cells, higher levels of ERS protein compared to normal pregnancy samples in URPL patients, increased severity of CHOP expression than normal pregnancy group, increased apoptosis, and pathology. suggests that migration-related pregnancy losses may improve. Key words: ERS, Unexplained Recurrent Pregnancy Loss, Human