Expression of peroxisome proliferator activation receptors (PPARs) and TNFα in placenta tissues in unexplained recurrent pregnancy loss: An immunohistochemical study

Abstract

Introduction. PPAR expression in placenta tissues regulates proinflammatory cytokine production and preserves the quiescence of the uterus during pregnancy. PPAR-γ regulates inflammatory response during gestation while PPAR-δ and TNFα play a central role at implantation, decidualization and placentation. However, their expression levels affect normal pregnancy and may cause gestational complications and miscarriage. The aim of this report is to investigate the relationship of these molecules with unexplained recurrent miscarriage. Materials-methods. The miscarriage group was obtained from 12 women, between the ages of 35 to 42 years, who miscarried during the 1st trimester of gestation and controls consisted of 12 healthy women, between the ages of 27 to 39 years, who had electively terminated their pregnancies, during the 1st trimester of gestation. The abortion material was processed and specimens taken were studied using immunohistochemical methods. Specimens were taken from decidua basalis and decidua parietalis. Monoclonal antibodies were used against PPAR-γ (Peroxisome Proliferator Activation Receptor γ), PPAR-δ and TNFα (Tumor Necrosis Factor alpha). The results were statistically analyzed with Mann-Whitney test. Results. Our research identified PPAR-γ expression in decidua basalis and decidua parietalis from control group and decidua basalis from miscarriage group. PPAR-δ expression was also identified in both deciduas from both groups. Statistically, no significant change in PPAR-γ and PPAR-δ expression was observed between recurrent miscarriage group and controls. On the contrary, a statistically significant upregulation of TNFα was identified in both deciduas between miscarriage group and controls (p<0.05). Conclusions. Our evidence did not support a possible role of PPARs expression in recurrent pregnancy loss. However, a potential involvement of TNFα in the syndrome was reported. Further research should be performed due to insufficient bibliographic data.