Expression of intercellular adhesion molecule-1 on the surface of peripheral blood and decidual lymphocytes of women with pregnancy-induced hypertension

Characterizing the immune cell population in the human fetal membrane

PROBLEM

This study localized CD45⁺ immune cells and compared changes in their numbers between term, not in labor (TNIL) and term, labor (TL) human fetal membranes.

METHOD OF STUDY

Fetal membranes (amniochorion) from normal TNIL and TL subjects were analyzed by immunohistochemistry (IHC), immunofluorescence (IF), and flow cytometry for evidence of total (CD45⁺ ) immune cells as well as innate immune cells (neutrophils, macrophages and NK cells) using specific markers. Fetal origin of immune cells was determined using polymerase chain reaction (PCR) for SRY gene in Y chromosome.

RESULTS

CD45⁺ cells were localized in human fetal membranes for both TNIL and TL. A threefold increase in CD45⁺ cells was seen in TL fetal membranes of (7.73% ± 2.35) compared to TNIL (2.36% ± 0.78). This increase is primarily contributed by neutrophils. Macrophages and NK cells did not change in the membranes between TNIL and TL. Leukocytes of fetal origin are present in the fetal membranes.

CONCLUSION

The fetal membranes without decidua contain a small proportion of immune cells. Some of these immune cells in the fetal membrane are fetal in origin. There is a moderate increase of immune cells in the fetal membranes at term labor; however, it is unclear whether this is a cause or consequence of labor. Further functional studies are needed to determine their contribution to membrane inflammation associated with parturition.

Significance of platelet endothelial cell adhesion molecule-1 (PECAM-1) and intercellular adhesion molecule-1 (ICAM-1) expressions in preeclamptic placentae

Although preeclampsia (PE) is one of the most important problems affecting pregnant women, etiologic factors in its development are still unclear. We aimed to investigate the expression levels of platelet endothelial cell adhesion molecule-1 (PECAM-1) and intercellular adhesion molecule-1 (ICAM-1) in preeclamptic and control healthy placentas. Placental tissue samples were obtained after delivery from patients diagnosed with PE, and from normal term pregnants and analyzed by immunohistochemistry for the expression levels of the two adhesion molecules PECAM-1 and ICAM-1. A strong expression of PECAM-1 in endothelial cells lining the vessel walls of placental villi in placentas of control group was found, but the intensity of PECAM-1 expression was highly reduced in placentas of PE group (p = 0.017). Conversely, a strong expression of ICAM-1 was observed in placental villi in PE, significantly higher than that of normal placentas (p = 0.005). The findings of a decrease of PECAM-1 expression and an increase of ICAM-1 expression in preeclamptic placenta suggest the existence of functional roles of these adhesion molecules in the pathophysiology of PE, probably by contributing to the reduced trophoblast invasion and the increased vascular damage, respectively. Inhibiting ICAM-1 (i.e., with ICAM-1 monoclonal antibody) and promoting PECAM-1 expression may be good therapeutic approaches to prevent PE symptoms in the future.

Placental apoptosis and adhesion molecules expression in the placenta and the maternal placental bed of pregnancies complicated by fetal growth restriction with and without pre-eclampsia

The aim of the study was to examine the expression of adhesion molecules VCAM-1 and ICAM-3 in placental tissue samples and placental bed (maternal decidual tissue) biopsies of pregnancies complicated by pre-eclampsia (PE) and fetal growth restriction (FGR), and to determine whether PE and FGR are associated with an increase in placental apoptosis. We studied placentas and placental bed samples of 49 third trimester pregnancies complicated by FGR (26 with associated PE, 23 without PE) and 25 normotensive healthy pregnant women. Placental apoptosis was assessed by the TUNEL method. Immunohistochemistry was used to assess expression of the VCAM-1 and ICAM-3. There was no significant difference in the staining intensity of VCAM-1 in placentas (p=0.472) and placental bed biopsies (p=0.754) of women delivering appropriate for gestational age and growth restricted fetuses (with and without associated PE). The amount of lymphocytes staining positively with ICAM-3 was significantly higher in both placental and placental bed biopsies of women delivering growth restricted fetuses compared with control pregnancies (p<0.001). Fetal growth restricted pregnancies with associated PE showed higher staining of ICAM-3 in placental compared with placental bed samples (p=0.049). In fetal growth restricted placentas, apoptotic nuclei were more abundant compared with control placentas (p<0.001). Increased expression of ICAM-3 on lymphocyte surface of both maternal and fetal side, suggests lymphocyte overactivation in PE and FGR. Increased placental apoptosis may play an important role in the pathogenesis or sequelae of PE.

The immune system in the oxidative stress conditions of aging and hypertension: favorable effects of antioxidants and physical exercise

Several studies have shown that both oxidative stress and inflammation are linked to the process of hypertension and that the immune system is also involved in this age-related process. More specifically, the oxygen stress related to immune system dysfunction seems to have a key role in senescence, in agreement with the oxidation/ inflammation theory of aging. From a practical point of view, and according to our own research, the immune functions change in a similar fashion in hypertension and aging. As antioxidant diet supplementation decreases oxidative stress, it may be useful to treat hypertension and increase longevity. Probably, these favorable effects are mediated by an antioxidant-induced improvement of the immune function. The practice of moderate physical exercise shows similar favorable effects, and indeed our studies on exercising hypertensive women demonstrate an improved immune function, probably linked to raised levels of intracellular antioxidant defenses. The present review summarizes a selection of data related to the above from other authors as well as some findings from our own work.