GLUT-9 EXPRESSION IN HUMAN TERM PLACENTAS OF DIET-REGULATED GESTATIONAL DIABETES PREGNANCIES

Abstract

Aim: Among the 14 identified GLUT isoforms, GLUT-1, GLUT-4 and GLUT-9 are considered crucial for placental glucose
transport. GLUT-9, one of the least investigated isoforms capable of transporting both glucose and fructose, is expressed in the syncytiotrophoblast and vascular endothelium. Since gestational diabetes mellitus (GDM) significantly affects both maternal and fetal health, this study aimed to analyse immunohistochemical expression of GLUT-9 in various placental compartments.

Methods: Placental samples were obtained from women with diet-regulated GDM (n=13) and healthy controls (n=11). To our
knowledge, this is the first study to assess GLUT-9 expression separately in decidual cells (DC), villous trophoblast (VTB), extravillous trophoblast (EVTB), and vasculosyncytial membranes (VSM). Immunohistochemistry was performed using an anti-GLUT-9 antibody, and expression was evaluated using the HSCORE method by two blinded perinatal pathologists.

Results: There were no statistically significant differences in maternal age, gestational age, fetal weight, neonatal sex, or
placental weight between the groups. Likewise, no significant differences were observed in GLUT-9 expression in DC (P=0.5620), EVTB (P=0.5620), VTB (P=0.1268), or VSM (P=0.2619).

Conclusions: The results of the study indicate that GLUT-9 expression does not differ between pregnant women with diet-controlled GDM and healthy pregnant women. Therefore, it can be concluded that GLUT-9 does not play a significant role in glucose transport in pregnancies that do not require insulin therapy; however, given the small sample size, further studies are needed.