In addition to VEGF-A, PlGF induces angiogenesis and affects proliferation and migration of endothelial cells (11). PlGF belongs to VEGF family and is a pro- angiogenic factor which is closely related to VEGF-A (12). Despite existence of some angiogenic growth factors in placenta, PlGF expression has a great importance (13). In human PlGF gene is mapped to chromosome 14q24 (14). PlGF protein which shows a main homology with VEGF, is predominantly expressed in trophoblast cells of placenta and its aberrant expression could lead to insufficiency in placental vasculature (11).
expressions of VEGF in both level of mRNA and protein in placenta of preeclamptic patients compared with the normotensive controls (54). Andraweera et al reported mRNAplacentalexpression of VEGFA and PlGF were reduced in preeclamptic patients compared to normal control pregnancy (55). In contrast, three studies showed the increase in expression of angiogenic factors such as VEGF in preeclampsia (26- 57). This contrast is also observed in microarray studies. In Lee et al study with aim of investigating cytokine- and oxidation-related genes or preeclampsia using DNA microarray analysis they found up- regulation of VEGFA mRNA that were confirmed using quantitative real time- polymerase chain reaction (QRT-PCR) (56). But Jarvenpaa et al showed down-regulation of VEGF in both early and late onset PE by microarray (58). Ranheim et al reported that there were no statistically significant differences in expression of VEGF in mRNA levels between the preeclampsia and the control group for either the decidual or placental tissues (59). Sgambati et al reported that in the cases of preeclampsia, the levels of VEGF mRNA were the same as the control group (60).
Oxygen is the key substrate for normal fetal develop- ment and growth therefore hypoxia is a leading cause of fetal growth restriction. After oxygen, glucose is the most important substrate for fetal growth and the only one that can be metabolized anaerobically . The second impor- tant cause of IUGR reduces glucose transfer to the fetus. Placenta is a source of alterations that lead to the reduced maternal-fetal glucose transfer. At least partially this could be due to the decreased placental glucose transporters (GLUT) expression, since previous data have suggested that transport across the basal membrane is the rate-limi- ting step in transplacental glucose transport . GLUTs are the members of sodium-independent transmembrane proteins that provide intracellular glucose transport . These molecules could play an important role in the de- velopment of fetal growth restriction in preeclampsia but its importance is not established yet. The aim of this study is to analyze glucose transporters GLUT-1 and GLUT-3 expression patterns in the terminal villi of the placentas from PE and IUGR cases.
invasive cytotrophoblasts. In the pregnancy disorder preeclampsia, cytotrophoblast invasion is limited to the superficial decidua, and few arterioles are breached. The purpose of this study was to determine whether cytotrophoblast expression of adhesion molecules in this disorder is also abnormal. Placental bed biopsy specimens from normal pregnancies and those complicated by preeclampsia were stained with anti-integrin antibodies. The results showed that adhesion molecule switching by invasive cytotrophoblasts is abnormal in preeclampsia, which suggests that this subpopulation of trophoblast cells fails to
The technique or sampling method in this study were made preeclampsia mice models by giving injection of 10ng iv anti-Qa-2 (ho- molog to human HLA-G) on days 1-4 of preg- nancy. Then divided into 2 groups, first with- out treatment or administration of L-Argi- nin(control), the second group was adminis- trated L-Arginin 200 mg/kgBW/ day on days 7-15 of pregnancy. On day 16 it was termi- nated, and took the placental sample then examined with immunohistochemical of HIF- 1-A expression. Results are assessed semi quantitatively according to the H-Score met- hod.
trations in the fetal blood and amniotic fluid of murine TRPV6 knockout (KO) fetuses are significantly lower than those in wild type fetus- es; however, the physiological role of placental TRPV6 remains unknown. A recent study sh- owed that samples of placental tissue obtained from women with preeclampsia contained lower levels of TRPV6 protein when compared with samples of healthy placental tissue . Histopathological examinations of placental tis- sue obtained from women with pre-eclampsia have revealed different morphological charac- teristics depending on the timing of disease onset. However, it is unknown whether such dif- ferences reflect differential placental gene expression. Therefore, we conducted the cur- rent study to examine TRPV6 expression in the placental tissue of women with early-onset PE and late-onset PE, and examine the role played by TRPV6 in the proliferation of trophoblast cells.
A limitation of our study is the lack of measurement of placental anandamide levels and NAPE-PLD expres- sion. Furthermore, our study had a case–control design, thus direct causation cannot be determined. Neverthe- less, abnormal placentation occurs in the first half of pregnancy, while the clinical syndrome only appears in the second, which rules out prospective studies on the placenta. It is also possible that increased CB1 expression is rather a consequence than a cause of preeclampsia, however there are no data in the literature demonstrating association between placental CB1 expression levels and PE risk factors or pathophysiological signals. Experimental studies are required to determine the causative role of in- creased placentalexpression of cannabinoid receptor 1 in preeclampsia.
In cluster 3 samples, integrated alterations were identified involving antigen presentation, allograft rejection, cytokine- cytokine receptor interaction, Jak-STAT and TGF-beta signaling, glycosaminoglycan biosynthesis, and metabolism. These are also in line with our prior transcriptional results in this “immunological” PE group , in which we charac- terized this cluster of patients as demonstrating evidence of maternal anti-fetal/placental rejection. While not as widely discussed in the literature, the primary involvement of heightened immune activation has been described in several previous studies of PE pathophysiology, along with these other metabolic pathways [60 – 66]. Interestingly, one of the most significant methylation and expression relation- ships observed in this cluster involved DNMT3A (one of the DNA methyltransferase enzymes responsible for de novo methylation): a CpG island site (cg05544807) was hypermethylated in the DNMT3A gene body, compared to cluster 1, and demonstrated a negative relationship to expression. While this likely has global implications for the DNA methylation pattern observed in these cluster 3 placentas, decreased expression of DNMT3A has been specifically implicated in immunological-associated disor- ders [67, 68] and abnormal placentation in preeclampsia . Therefore, this CpG site may serve as a potential target for the epigenetic modulation of pathological gene expression in this PE subtype.
conducted unsupervised clustering analysis . The study identified three main subclasses of PE based on gene expression - late-onset PE, which is mostly associated with term deliveries and maternal risk factors (“maternal PE”); early-onset PE, which is likely placental in origin and is more frequently associated with IUGR (“canonical PE”); and a third subclass of PE that is also severe and can co- occur with IUGR but is likely due to poor maternal-fetal compatibility (“immunologic PE”) . Interestingly, cluster analysis based on DNA methylation data in PE placentae revealed a similar clustering pattern into the three subclasses of PE . In this study, 8763 and 340 differentially methylated sites were found in the “canon- ical” and “immunologic” subclasses respectively . Wilson et al. also showed differentially methylated sites, as many as 599 sites, in EO-PE and only 5 in late-onset PE . These studies show differences in gene expression and in epigenetic mechanisms between subclasses of PE, emphasizing that each subclass has a unique underlying pathophysiology. In addition, these studies demonstrate the benefits of combining epigenetic and gene expression data to improve our understanding of molecular mecha- nisms in the placenta.
most lipids require active placental transport through the activity of lipoprotein receptors, lipases and fatty acid binding proteins [16, 17]. Abnormal maternal lipids or altered placental lipid processing could contribute to the altered infant growth and change in cord lipopro- teins seen in PE. The expression and activity of lipopro- tein lipase (LPL) has been variably found to be higher, lower or unchanged in placentae from women with PE or IUGR compared to uncomplicated pregnancy [18–26]. Endothelial lipase (EL) gene expression has been reported to be decreased in IUGR  but has not been analysed in PE. The expression and localization of the intracellular lipases adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) have not previously been examined in placentae from women with pregnancies complicated by PE or IUGR.
the best of knowledge, PIGF can induce the pro- liferation, migration and activation of vascular endothelial cells, especially the microvascular endothelial cells, and can also act as chemo- tactic factor of endothelial cell growthfactor to regulate the growth of endothelial cells . The same as VEGF, PIGF was also demonstrat- ed can form heterodimers that show only weak biological activity, suggesting that PIGF may negatively regulate VEGF-induced angiogenesis via formation of biologically inactive heterodi- mers . In addition, PIGF can promote migra- tion of monocytes and endothelial cells, and increase the permeability of endothelial cells, suggesting that PIGF plays a prominent role in inducing angiogenesis and maintaining the nor- mal structure and function of blood vessel . In conclusion, we show that, among the study we conducted, a negative correlation between decreased PIGF expression and increased BP, and a positive correlation between birth weight and MVD were found. These findings suggest- ing that the expression level of PIGF can be the detection index of PE, which severs as a detec- tion index for diagnosis and treatment of PE. Nevertheless, the specific functions of PIGF expression in symptoms of PE were not revealed in our study, which need further investigation. Acknowledgements
proteinuria. The causes of preeclampsia are complex and beyond the scope of this review. It has been shown that plasma TGFB1 [100-104] and TGFB2  levels are ele- vated in patients with preeclampsia. Experimental evidence also suggests that failure to downregulate the expression of TGFB3 during early gestation may cause trophoblast hypo- invasion and preeclampsia . Interestingly, the levels of soluble endoglin, a transmembrane TGFβ co-receptor, are elevated in sera of women with preeclampsia, which may be associated with vascular complications and hyperten- sion in these patients [107,108]. Based on these findings, TGFB proteins may serve as potential biomarkers for pre- eclampsia . It is thus plausible that optimal TGFβ sig- naling activity is required to keep preeclampsia in check by maintaining normal trophoblast invasion during implant- ation and placentation. However, another study showed that TGFBs1-3 are not expressed in villous trophoblasts, and TGFB1 and TGFB3 are not expressed in the extravil- lous trophoblast either. The expression of TGFBs1-3 in the placenta is not altered in patients with preeclampsia . Moreover, there are also reports indicating that concen- trations of TGFB1 in serum are indistinguishable be- tween patients with preeclampsia and normal controls [110-112]. In addition, the levels of activin A and in- hibin A, but not inhibin B, are increased in patients with preeclampsia [113-116]. Thus, the role of TGFβ signal- ing in the pathophysiological events of preeclampsia awaits further elucidation.
Female-biased expression of X chromosome genes is commonly due to escape from X-chromosome inactivation (XCI) (19). Of the 47 female-biased genes in the placenta, only 19 had previously reported to escape from XCI (14, 15), and the other 28 were classified either as inactivated, variable, or unknown (Figure 2C and Supplemental Table 3). Unlike in the mouse, XCI in the human placenta is not par- ent-of-origin specific (20), and direct assessment of biallelic expression of X chromosome genes is not possible using analysis of mRNA from whole tissue biopsies. However, identifying genes that escape XCI is also informed by analysis of DNA methylation (19); escaped genes do not exhibit sex-related differences in promoter methylation, whereas the promoter regions of genes subject to XCI are generally hypermethylated in females. Therefore, we compared promoter methylation in healthy male and female placental samples using whole genome oxidative bisulphite DNA-seq (Figure 3A). Both the known and potentially novel placenta-specific escaped genes had similar levels of promoter methylation in male and female tissues, whereas genes without sex-biased expression demonstrated promoter hypermethylation in females. An analogous pattern was also observed in male-biased X chromosome genes, which exhib- ited promoter hypermethylation in females. We replicated these results in a further group of male and female samples using SureSelectXT Methyl-Seq (Agilent) (Figure 3, B and C, and Supplemental Tables 5 and 6). These findings indicated that the placenta had a unique profile of genes escaping XCI compared with other human tissues.
We looked for correlation between high VEGFR- 1 expression (score +3) and complication (com- bined groups of eclampsia and HELLP syndrome). The percentage of sample with score +3 was higher in severe preeclampsia with complication (66.7%) than without complication (37.8%). There was sig- nificant difference (p=0.028) in the strength of VEGFR-1 expression between the group with com- plication of severe preeclampsia (3.3 times risk) and the group with no complication.
In the present study, a significant decrease in the concentrations of free PlGF was also found in the sera of women with preeclampsia compared to the sera of control women (Fig.2). PlGF also belongs to the VEGF family and shares 53% homology with VEGF (36). At physiological concentrations, it has been shown to be a very weak stimulator of endothelial cell proliferation (37). On the other hand, PlGF potentiates the action of low doses of VEGF on microvascular endothelial cells. PlGF also acts by binding with VEGFR- 1/Flt-1 and results in non- branching or least branching of blood vessels (38, 39). Thus PlGF and VEGF, together enhance the growth of new blood vessels (angiogenesis), and maintain the normal function of endothelial cells lining the blood vessels (39). Physiologically, the two growth factors, together with the oxygen diffusive placental tissue conductance, may promote remodeling of the materno-fetal interface. The decreased concentration of free PlGF and VEGF in the serum of preeclamptic patients may lead to endothelial cell dysfunction in maternal circulation (29). A significantly increased concentration of sFlt-1 in the sera of preeclamptic women was also observed in the present study when compared to control (Fig.3). One possible reason for this is the effect of inadequate perfusion on the growth of the feto- placental unit, which may lead to an increase in serum sFlt-1 values (40). sFlt-1 is a soluble receptor of VEGF (23,27) which is generated by a splice variant of the Flt-1 gene and contains the extracellular ligand-binding domain, and lacks the transmembrane and cytoplasmic domains (27). sFlt-1 may not primarily be a receptor transmitting a mitogenic signal, but may inhibit the activity of VEGF on the vascular endothelium by preventing the binding of VEGF to VEGFR-2 (41). Previous
. VEGF-A forms homodimer with itself and/ or heterodimers with PIGF, and acts by binding to its two cell surface tyrosine kinase recep- tors, VEGFR1 (FLT-1) and VEGF2 (KDR/FLK-1). PIGF binds only to VEGFR1 . Compelling evi- dence suggests that these potent angiogenic growth factors are involved in normal and abnormal implantation . For example, they participate in the regulation of early placental angiogenesis, maternal stromal changes and spiral artery remodeling . In the human Fallopian tube, VEGF is localized in the epithe- lial cells, smooth muscle cells, and blood ves- sel cells in a region-specific manner [11, 12], and significantly higher levels of tubal VEGF and VEGF receptor mRNAs are detected in women with a hydrosalpinx , which is defined as tubal dilation and abnormal fluid accumulation . Moreover, in vitro studies have shown an increase in VEGF and soluble VEGF receptor secretion in human tubal epithelial cells and stromal fibroblasts in response to hypoxic stim- ulation . It has been shown that VEGF-A and VEGF receptor mRNAs are significantly increased in the implantation site compared to non-implantation sites of human Fallopian tubes , and these are associated with tro- phoblastic invasion into the tubal wall in vivo . These results suggest that the develop- ment of tubal EP could contribute to the eleva- tion of circulating VEGF-A levels. In fact, circu- lating levels of VEGF-A have been shown to change in women with EP [17-23]. Moreover, ligation of the Fallopian tube, which mimics the tubal occlusion that likely induces an EP in women, increases VEGF protein expression in rat Fallopian tubes . Furthermore, in vitro experiments have shown that insulin-like growthfactor-1 and interleukin-1β directly regu- late VEGF and VEGFR expression in human tubal epithelial cells and stromal fibroblasts [25, 26]. Collectively, these observations show that different molecules contribute to the regu- lation of VEGF synthesis and secretion, but their precise roles in tubal EP are not clearly understood.
McCusker et ai. 1 99 1 ; Owens et al. 199 1 ). For example, in sheep, plasma levels of IGFBP-2 and IGFBP-2 mRNA in the liver are high in the fetus in mid to late gestation and decrease towards adult levels near term, whereas the reverse is true for IGFBP-3 over the same period (Carr et ai. 1 995). In ruminants such as sheep and cattle, a major increase in plasma IGFBP-3 concentrations in postnatal life coincides with the appearance of the hepatic GHR (Butler & Gluckman, 1 986), suggesting that hepatic GHR may be involved in regulating plasma IGFBP-2 and -3 concentrations. This suggestion is consistent with the abovementioned reports that circulating concentrations of plasma IGFBP-2 and -3 are sensitive to nutritional and GH status, which are important components in up-regUlating hepatic GHR in ruminants. However, an increase in plasma IGFBP-3 occurs even in GH-deficient humans (Kanety et al. 1 993) and rats (Clemmons et al. 1 989; Zapf et ai. 1 989), when they are treated with IGF-I. For example, in patients with Laron-type dwarfism (LTD) which are characterized by the absence of GH receptor activity, chronic treatment with IGF-I increases serum IGFBP-3 up to 1 9-fold after six months of therapy (Kanety et al. 1 993). These data indicate that GHR may not be an essential component in regulating plasma IGFBP-3 levels and further suggest that plasma IGF-I may be crucial in regulating IGFBP-3 . Further support is given in recent reports with sheep (Carr et al. 1 995) and cattle (Skaar et ai. 1 994), where developmental changes in plasma IGFBP-3 were studied, and in which its concentration was correlated positively with circulating concentrations of IGF-I. In one of these studies, where circulating concentrations of IGFBP-2 and IGF-II were measured simultaneously (Carr et ai. 1 995), a developmental change in plasma IGFBP-2 was correlated positively with changes in plasma IGF-II, indicating a similar mechanism is operating between IGF-II and IGFBP-2.
In this study, we show the folate supplementa- tion might improve the growth of the placenta and fetus exposed to Dex. In vitro, folate might ameliorate the Dex-induced supress of migra- tion and improve the expression/activity of MMP2 and 9 in HTR8/SVneo cells. Our study Figure 2. Effects of prenatal dexamethasone and/or folic acid on the migration and the MMPs expression in HTR-8/ SVneo cells. A. HTR-8/SVneo cells migrating from the upper chamber (green), magnification ×100, Bar = 100 μm. B. Cell density of migrated HTR-8/SVneo cells. Each chamber, cells were calculated from five randomly collected visions under ﬂuorescence microscopy. C. The MMP9 mRNA level of HTR-8/SVneo cells. Data represents mean ± S.E.M from three assays, * P < 0.05, ** P < 0.01, *** P < 0.001. NN, control; ND, Dex treatment; FN, folate treatment;
postnatal platelet counts (n = 202). Any episode of thrombocytopenia (<100 × 10 9 /l) at ≥30 weeks postmenstrual age (at onset of ROP) was independently associated with severe ROP, requiring treatment. Infants with severe ROP also had a lower weekly median platelet count compared with infants with less severe ROP. In a mouse oxygen-induced retinopathy model of ROP, platelet counts were lower at P17 (peak neovascularization) versus controls. Platelet transfusions at P15 and P16 suppressed neovascularization, and platelet depletion increased neovascularization. Platelet transfusion decreased retinal of vascular endothelial growthfactor A (VEGFA) mRNA and protein expression; platelet depletion increased retinal VEGFA mRNA and protein expression. Resting platelets with intact granules reduced neovascularization, while thrombin-activated degranulated platelets did not. These data suggest that platelet releasate has a local antiangiogenic effect on endothelial cells to exert a downstream suppression of VEGFA in neural retina. Low platelet counts during the