G.D. Zappoli Thyrion

Expression of vascular endothelial growth factor receptor types 1, 2 and 3 in placenta from pregnancies complicated by hypertensive disorders

The aim of the present study was to determine the expression of vascular endothelial growth factor (VEGF) family receptors (VEGFR) in placentas from pregnancies complicated by hypertensive disorders of different clinical severity. Placental tissue from women with gestational hypertension, pre-eclampsia, pre-eclampsia with haemolysis, elevated liver enzymes and low platelets (HELLP syndrome) and normotensive women, as a control group, was examined. Immunohistochemical techniques, reverse transcription-polymerase chain reaction and western blot were used to evaluate receptor expression. In cases with gestational hypertension, as well as in control cases, VEGFR-1 and VEGFR-3 immunoreactivity was detected in all placental components, whereas in placentas from the pre-eclampsia and pre-eclampsia with HELLP syndrome groups, VEGFR-1 and VEGFR-3 immunoreactivity was detected only in some portions of trophoblast and/or some vessels and/or clusters of stromal cells. In the control group, VEGFR-2 immunoreactivity was observed only in the vessels, whereas the hypertensive groups showed VEGF-2 immunoreactivity also in trophoblast and stromal cells. The mRNA levels of the three receptors in the group with gestational hypertension were higher with respect to those in the control group. Placentas from pregnancies with pre-eclampsia showed lowest mRNA expression levels, whereas placentas from women with pre-eclampsia plus HELLP syndrome showed higher mRNA expression levels with respect to the three other groups. Receptor protein levels were lower in pathological cases compared with levels in the control group. These findings demonstrate a dysregulation of placental expression of VEGF family receptors related to the degree of clinical severity of the hypertensive disorder.

Sialic acid in human testis and changes with aging

The aim of the present study was to investigate the distribution of the glycoconjugates sialoderivatives in the human testis. Orchidectomy specimens from men aged 18-30 years (Group 1) and from men aged 70-93 years (Group 2) were obtained at autopsy. The study was performed using digoxigenin-labelled lectins, namely Maackia amurensis II lectin (MAA), Sambucus nigra agglutinin (SNA) and Arachis hypogaea lectin (PNA), in addition to enzymatic and chemical treatments (neuraminidase, KOH-neuraminidase, mild oxidation-neuraminidase, mild oxidation-KOH-neuraminidase, strong oxidation-neuraminidase, strong oxidation-KOH-neuraminidase), to characterise the different glycosidic linkages of the sialoderivatives and to obtain information regarding their structure. In all Group 2 samples, sialic acids linked alpha-2,3 to galactose and alpha-2,6 to galactose/N-acetyl-D-galactosamine (Gal/GalNAc), revealed by MAA and SNA, respectively, were observed in testicular interstitial tissue and in the lamina propria. Sialic acid linked alpha-2,6 to Gal/GalNAc was detected in only some samples from Group 1. After treatment, PNA showed structural changes and/or the gradual disappearance of sialic acid linked to D-galactose-beta(1-3)-N-acetyl-D-galactosamine in testicular components with aging. These findings indicate that changes in the metabolism of sialoderivatives in the testis could be related to morphofunctional changes in various testicular components typical of this organ during aging. This suggests that sialoderivatives are important in the functionality of the mature testis in men, as well as its involution.

Effect of impaired glucose tolerance during pregnancy on the expression of VEGF receptors in human placenta

The aim of the present study was to determine the expression of vascular endothelial growth factor (VEGF) receptors VEGFR-1, VEGFR-2 and VEGFR-3 in placentas from pregnancies complicated by altered glycaemia. Placentas from women with physiological pregnancies (Group 1), pregnancies complicated by minor degree of glucose intolerance (MDGI, Group 2) and by gestational diabetes mellitus (GDM) treated with insulin (Group 3) were collected. Immunohistochemistry, RT-PCR and western blot were employed to evaluate receptor expression. In the three study groups, VEGFR-1 immunoreactivity was detected in all the placental components. VEGFR-2 immunoreactivity was observed in the vessels of all the placentas from Groups 1 and 2, but only in some placentas of Group 3. VEGFR-3 reactivity was observed in all the components of Group 1; in Groups 2 and 3 reactivity was observed in some portions of the trophoblast or the whole trophoblast, and in the stroma. VEGFR-1 and VEGFR-2 mRNA levels in Groups 2 and 3 were significantly higher compared with Group 1, whereas those of VEGFR-3 were significantly lower. Receptor protein levels were significantly lower in Groups 2 and 3 compared with Group 1. These findings demonstrated dysregulation of expression of the three placental receptors, both in GDM and in MDGI.