Expression of the serotonergic system components in the placenta in various types of preeclampsia

Abstract

BACKGROUND: The serotonergic system plays an important role in the formation and development of the feto-placental complex. The study of the expression of the serotonin system components, including placental 5-HT2A (serotonin receptor) and SERT (serotonin transporter), in preeclampsia will create prerequisites for discovering new ways to correct hypertensive pregnancy complications and methods of influencing pregnancy outcomes. AIM: The aim of this study was to compare the expressions of 5-HT2A and SERT in placental tissue in pure preeclampsia and its combinations with other complications of pregnancy. MATERIALS AND METHODS: A comparative cohort study was conducted among patients with different preeclampsia phenotypes: preeclampsia (n = 6), preeclampsia and gestational diabetes mellitus (n = 6), gestational diabetes mellitus and superimposed preeclampsia (preeclampsia + chronic arterial hypertension) (n = 6), and normal pregnancy without pregnancy complications (n = 6). The expression of 5-HT2A (Abcam, USA) and SERT (BiossAntibodies, USA) was studied in placenta samples from all study groups by immunohistochemical method. Morphometric analysis was performed using the VideoTest-Morphology 5.2 program (Videotest Ltd., Russia). The database was constructed and statistical processing was performed using Microsoft Excel 2007 (Microsoft Corporation, USA) and the StatTech program v. 2.6.4 (Stattech Ltd., Russia). RESULTS: The expression of SERT and 5-HT2A is higher in the studied pregnancy complications when compared to the normal one. The relative 5-HT2A expression area in the placenta among the studied nosologies is higher in preeclampsia without gestational diabetes mellitus or in superimposed preeclampsia in combination with chronic arterial hypertension compared to expression in placentas in preeclampsia in combination with gestational diabetes mellitus or in preeclampsia in combination with gestational diabetes mellitus and chronic arterial hypertension (p = 0.02 and p = 0.017, respectively). The relative area of SERT expression is higher in preeclampsia without gestational diabetes mellitus or chronic arterial hypertension and in preeclampsia in combination with gestational diabetes mellitus compared to preeclampsia in combination with gestational diabetes mellitus and chronic arterial hypertension (p = 0.002 and p = 0.012, respectively). CONCLUSIONS: The highest expressions of 5-HT2A and SERT among the studied preeclampsia phenotypes were found in placentas in preeclampsia without gestational diabetes mellitus or chronic arterial hypertension.