Lectin Binding in the Human Umbilical Cord from Normally Grown Pregnancies and from Pregnancies Complicated by Intra-Uterine Growth Retardation with Absent or Reversed Diastolic Flow

Abstract

The content and the distribution of the glycoconjugate sugar residues were investigated in the human umbilical cord from normally grown pregnancies and from pregnancies complicated by intra-uterine growth retardation with absent or reversed flow in the umbilical artery. The gestational age range was 29–41 weeks. For this purpose, a battery of eight horseradish peroxidase conjugated lectins was used (ConA, WGA, PNA, SBA, DBA, LTA, UEA I, and OOA; see text). Our data showed that in both study groups ConA, WGA and PNA (after neuraminidase digestion) and LTA, UEA I, and OOA reacted with Wharton’s jelly and vessels of the umbilical cord from the first weeks of gestation considered. SBA reactivity was observed only in the amniotic epithelial cells of the jelly and in the endothelial cells of the vessels. The reactivity with the most part of the lectins decreased or was lacking in the various components of the umbilical cord between 39 and 41 weeks of gestation in the normal group and between 36 and 37 weeks of gestation in the pathological one. Moreover, the intensity of reactivity with ConA, WGA and PNA (after neuraminidase digestion) and LTA, UEA I, and OOA in the normal group and with PNA (before and after neuraminidase digestion) and LTA and OOA in the pathological one was stronger in the peripheral portion of the jelly with respect to the adventitial one. The reactivity with ConA and UEA I was stronger in the vein than in the arteries in both study groups. Some hypotheses are reported on the role played by the sugar residues in the normal and pathological umbilical cords.

Lectin binding in the umbilical cord in altered glycemia

“…3)-N-acetyl-D-galactosamine and a-Lfucose (LTA and UEA I) were more abundant in the peripheral portion of the jelly with respect to the adventitial one in according to the data observed in a previous study [7]. Even in the groups 2 and 3 N-acetyl-D-glucosamine, D-galactose-(b1 !…”

“…3)-N-acetyl-D-galactosamine and a-Lfucose (UEA I) had the same distribution in the two portions; in the group 3 also sialic acid showed this distribution, while in the group 2 it was present only in the adventitial portion. As suggested by a previous study [7], the different amount of carbohydrates in the two portions might contribute to exert their different functions: protection of the vessels by the peripheral portion and diffusion of substances between the vessels by the adventitial one. In the pathological groups, in particular in the minor degree of glucose intolerance, the lacking of some carbohydrates in both the portions might contribute to impair their functions.…”

“…Scanty data are available in the literature concerning the glycoconjugates oligosaccharides in the umbilical cord from physiological pregnancies and from those complicated by various types of pathologies [4][5][6][7].…”

Endothelial heterogeneity and adhesion molecules N-glycosylation: Implications in leukocyte trafficking in inflammation

“…Importantly, this conclusion is also supported from studies comparing patterns of lectin binding in human tissues under healthy and diseased states. Examination of lectin binding to umbilical cords demonstrated increased ConA and UEA binding to the vein compared with the artery and lectinbinding patterns during pregnancy complications are altered in both pattern and intensity within the vasculature (Sgambati et al 2003(Sgambati et al , 2007. Our own studies have shown that there Scott et al (2012).…”