Angiogenesis In Placenta Research Articles

617: The association of VDR and angiogenic potential in early onset severe preeclampsia (EOSPE)

early onset severe preeclampsia (EOSPE) Angela Hawk, Satomi Kohno, Donna Johnson, Christopher Robinson Medical University of South Carolina, Obstetrics and Gynecology, Charleston, SC, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC OBJECTIVE: Both pro and antiangiogenic factors are essential for normal placentation. Recent cardiovascular literature has revealed the important role of vitamin D in angiogenesis. Vitamin D deficiency has been linked with both increased risk for preeclampsia and intrauterine growth restriction (IUGR) in patients with EOSPE. Our goals were to identify the association between vitamin D signal, angiogenesis, IUGR and EOSPE. mRNA expression in EOSPE placenta was compared by race and IUGR. Vitamin D receptor(VDR), vascular endothelial growth factor (VEGF), placental growth factor(PlGF), retinoid X receptor(RXR), and soluble fms-like tyrosine kinase(sFlt-1) mRNA were quantified by real-time PCR(Q-PCR). STUDY DESIGN: RNA was extracted from placental samples (n 32) and quality/quantity verified via gel electrophoresis; non-contamination of genomic DNA was validated by Q-PCR. Primers were chosen via a literature/database search for genes of interest and housekeeping genes. RNA samples were reverse-transcribed, and expression levels quantified by comparison with serially diluted standard samples with known concentrations of target cDNA. Statistical analysis was performed with Wilcoxon Rank Sum tests and simple linear regression. RESULTS: African Americans (AA) showed significantly lower expression levels of sFlt-1 than Caucasians(C). VEGF expression level was lower in AA than in C, although it was not statistically significant (p 0.09). Presence of IUGR did not show any effects on mRNA expression. VDR expression was positively correlated with PlGF, sFlt-1, RXR-A and RXR-B, but not with VEGF. CONCLUSION: These associations suggest that Vitamin D signal could be responsible for an increase in both proand antiangiogenic factors. mRNA expression levels do not simply equate to amount of translated protein, indicating that the relationship of VDR to race and IUGR in EOSPE patients represents a more complex pathway. More investigation on vitamin D and angiogenesis in placenta is required to better understand its relationship with EOSPE. 618 Persistent urinary podocyte loss after preeclamptic pregnancies may be a possible mechanism of chronic renal injury Angelica Garrett, Iasmina Craici, Wendy White, Carl Rose, Brian Brost, Steven Wagner, Joseph Grande, Vesna Garovic Mayo Clinic College of Medicine, Maternal Fetal Medicine, Rochester, MN, Mayo Clinic College of Medicine, Hypertension and Nephrology, Rochester, MN OBJECTIVE: Studies show that proteinuria in preeclampsia is associated with podocyturia. Epidemiological studies have shown that preeclampsia is associated with future proteinuria and renal disease. Little is known about the resolution of podocyturia from time of delivery to 6wks postpartum. We postulate that persistent urinary podocyte loss after preeclamptic pregnancies may lead to proteinuria and chronic renal injury. STUDY DESIGN: The diagnoses of preeclampsia and HELLP were confirmed using standard clinical criteria. Random urine samples were obtained within 24hrs prior to delivery and 5-8wks postpartum (on average, 44 7d and 43 4d after delivery for cases and controls, respectively). Urine sediments were cultured for 24hrs to select for viable cells. Podocin staining was used to identify podocytes and podocyturia was expressed as a ratio of the number of podocytes to the creatinine (Cr) content of the respective urine sample. RESULTS: Delivery samples were obtained from 15 patients in the PE/ HELLP group and 23 normotensive controls. Postpartum samples were available for 10 of 15 cases and 18 of 23 controls. At delivery, patients with PE/HELLP had significantly higher proteinuria, (median 0.78g/24hrs; IQR 0.16-1.21) than normotensive controls (median 0.09g/24hrs; IQR 0.07-0.2). Podocyturia was present in all patients with PE/HELLP (median 0.77 podocytes/mg Cr; IQR 0.28-1.78) and in one patient (0.06 podocytes/mg Cr) from the control group. Postpartum proteinuria was similar between women with PE/HELLP (median 0.03g/24hrs; IQR 0.02-0.04) and those with normotensive pregnancies (median 0.03g/24hrs; IQR 0.02-0.05). Podocyturia was present in 3 of 10 women with PE/HELLP (median 0.63 podocytes/mg Cr; IQR 0.43-1.14) and in none of the normotensive controls. CONCLUSION: Persistent urinary podocyte loss after preeclamptic pregnancies may constitute a marker of ongoing renal injury. Longitudinal studies of the time course alteration of urinary podocyte loss after the affected pregnancies are needed. VDR and angiogenic factors

In vivo and in vitro research study of the influence on placenta angiogenesis by gene silencing of netrin-1

To study influence on angiogenesis of placenta by gene silencing of netrin-1. Netrin-1 gene in human umbilical vein endothelial cells (HUVEC) and placenta of pregnant rats were silenced by RNA interference. The following methods were used in this study, including the phenytetrazoliumromide (MTT) for viability, clone formation for proliferation, transwell for migration, and tube formation for angiogenesis in vitro. The change of fetal growth was recorded. Placental microvessel density in pregnant rats was measured by immunohistochemical CD(34) staining in vivo. (1) HUVEC: viability and proliferation of HUVEC were remarkably inhibited by gene silencing of netrin-1, which number of clone formation, migration cell, tube formation were from (69 ± 6)%, 86 ± 17, 37 ± 9 decreased to (46 ± 5)%, 46 ± 13 and 17 ± 5 (P < 0.05) respectively. (2) Placenta of pregnant rats: after netrin-1 gene silenced, fetal weight were decreased from (2.39 ± 0.17) g to (2.12 ± 0.10) g (P < 0.05). Placental microvessel density was decreased from (258 ± 38)/mm(2) to (197 ± 32)/mm(2) in vivo (P < 0.05). Gene silencing of netrin-1 could inhibit viability, proliferation, migration, tubal formation of HUVEC and angiogenesis of placenta. Netrin-1 plays an important role in regulating angiogenesis in placenta.

Lack of evidence for inhibition of angiogenesis as a central mechanism of the antiarthritic effect of methotrexate.

The aim of this study was to investigate whether methotrexate (MTX) has an antiangiogenic effect and whether this property plays a role in the control of rheumatoid arthritis (RA). A human placenta angiogenesis assay was used to examine the antiangiogenic effects of MTX in vitro. In addition, DBA/1 mice were used to compare the antiarthritic effect of MTX in collagen-induced arthritis (CIA) and its antiangiogenic effect in a murine in vivo matrigel model for angiogenesis. The spreading of microvessels from placental vessel fragments was not significantly inhibited by MTX. Treatment with MTX reduced significantly the incidence of CIA in DBA/1 mice in a dose-dependent manner. However, treatment with the same doses of MTX did not significantly reduce vessel growth in subcutaneous depots of bFGF-enriched matrigel. These data support the hypothesis that inhibition of angiogenesis does not significantly contribute to the antiarthritic effect of MTX seen in patients and animal models for RA. Therefore, the combination of MTX with antiangiogenic drugs appears to be a rational strategy in the treatment of RA.