Membrane serotonin transporter as a Biomarker of Pulmonary arterial hypertension in children with Congenital Heart Defect

Abstract

18 young children (aged from 1 month old to 2 years old) with congenital heart disease were observed. During observation they were divided into 2 groups. Group I-8 children with CHD, not complicated by PAH. Group II 11 children with CHD, complicated by PAH. The content of serotonin and its transporter in platelets, the amount of serotonin in serum were determined. Serotonin content was determined by enzyme-linked immunosorbent assay. The study was performed using the Serotonin ELISA diagnostic kit, IBL Hamburg on the Evolis automated robotic station (BioRad). To determine the Sodium-Dependent serotonin transporter (SLC6A4) there was used the method of quantitative sandwich ELISA of Cusabio production. The main initiator of the development of PAH is development of endothelial dysfunction of the pulmonary vessels. Since the cause of this dysfunction is associated with functional disorders of the serotonergic system, our task was to determine the content of SERT and serotonin in platelets in the studied groups. We suggest that the serotonin transporter (SERT), which is responsible for the proliferation of the pulmonary artery smooth-muscle cells (PASMC), can be used as a biomarker for predicting and diagnosing PAH in children with CHD. The need for early biomarkers in the diagnosis of PAH in children is claimed by scientists from many countries of the world [1, 2]. The results of our studies showed a significant increase in the concentration of SERT in platelets in group II, compared with group I more than several times. The serotonin content in platelets in children of group II tended to decrease as compared with group I. Perhaps, an excessive increase in transporters in platelets is sufficient in itself for the induction of PASMC hyperplasia and the subsequent development of PAH. It is necessary to continue research in this direction, which will help to reveal and understand the molecular mechanisms by which SERT regulates the proliferation of PASMC and the role of serotonin and its transporter in the development of PAH in children.