Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(726)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: BMC Systems Biology
February/19/2013
Abstract
BACKGROUND
In this study we explored preeclampsia through a bioinformatics approach. We create a comprehensive genes/proteins dataset by the analysis of both public proteomic data and text mining of public scientific literature. From this dataset the associated protein-protein interaction network has been obtained. Several indexes of centrality have been explored for hubs detection as well as the enrichment statistical analysis of metabolic pathway and disease.
RESULTS
We confirmed the well known relationship between preeclampsia and cardiovascular diseases but also identified statistically significant relationships with respect to cancer and aging. Moreover, significant metabolic pathways such as apoptosis, cancer and cytokine-cytokine receptor interaction have also been identified by enrichment analysis. We obtained FLT1, VEGFA, FN1, F2 and PGF genes with the highest scores by hubs analysis; however, we also found other genes as PDIA3, LYN, SH2B2 and NDRG1 with high scores.
CONCLUSIONS
The applied methodology not only led to the identification of well known genes related to preeclampsia but also to propose new candidates poorly explored or completely unknown in the pathogenesis of preeclampsia, which eventually need to be validated experimentally. Moreover, new possible connections were detected between preeclampsia and other diseases that could open new areas of research. More must be done in this area to resolve the identification of unknown interactions of proteins/genes and also for a better integration of metabolic pathways and diseases.
Publication
Journal: Cancer genetics and cytogenetics
April/20/2005
Abstract
Analysis of gene expression pattern is a useful approach to evaluating the biological behavior and clinical outcome of several human malignancies. Differentially expressed genes in malignant squamous cervical cells and the feasibility of gene expression profiling on squamous cervical cells obtained from cervical swabs were investigated. Cervical squamous cells from three women with high-risk human papilloma virus (HR-HPV) positive invasive squamous cervical carcinoma and from three HPV-negative women with normal ectocervical smears were analyzed with cDNA array. Immunoblot analysis was performed to detect the proteins corresponding to the highest upregulated genes with cDNA array. mRNA expression of ERBB2, KIT, FLT1, MYCN, RAS, CDKN2A, CCND1, NME1, NME2, MET, FGF7, FGFR2, and STAT1 was increased in malignant samples. Several expressed genes associated with antiapoptosis (such as BCL2), cell structuring, or cell attachment were also upregulated in carcinoma cells. Decreased gene expression was observed for members of the transforming growth factor receptor superfamily (TGF) and integrin family, interleukin 1 (IL1), and insulin-like growth factor binding proteins (IGFBPs). This study shows the feasibility of gene expression profiling of cervical squamous cells obtained with cytobrushes by identifying a characteristic gene expression pattern that clearly distinguishes between malignant and normal cervical epithelia of squamous type. We hypothesize that this noninvasive technique could be used in the evaluation of ambiguous Papanicolaou (PAP) smears.
Publication
Journal: Journal of the National Cancer Institute
October/11/2015
Abstract
BACKGROUND
Genetic association studies have traditionally focused on associations between individual single nucleotide polymorphisms (SNPs) and disease. Standard analysis ignores interactions between multiple SNPs and environmental exposures explaining a small portion of disease heritability: the often-cited issue of "missing heritability."
METHODS
We present a novel three-step analytic framework for modeling gene-environment interactions (GEIs) between an angiogenesis candidate-gene pathway and three lifestyle exposures (dietary protein, smoking, and alcohol consumption) on colon cancer risk and survival. Logic regression was used to summarize the gene-pathway effects, and GEIs were modeled using logistic regression and Cox proportional hazards models. We analyzed data from 1541 colon cancer case patients and 1934 control subjects in the Diet, Activity and Lifestyle as a Risk Factor for Colon Cancer Study.
RESULTS
We identified five statistically significant GEIs for colon cancer risk. For risk interaction, odds ratios (ORINT) and 95% confidence intervals (CIs) were FLT1(rs678714) and BMP4(rs17563) and smoking (ORINT = 1.64, 95% CI = 1.11 to 2.41 and ORINT = 1.60, 95% CI = 1.10 to 2.32, respectively); FLT1(rs2387632 OR rs9513070) and protein intake (ORINT = 1.69, 95% CI = 1.03 to 2.77); KDR(rs6838752) and TLR2(rs3804099) and alcohol (ORINT = 1.53, 95% CI = 1.10 to 2.13 and ORINT = 1.59, 95% CI = 1.05 to 2.38, respectively). Three GEIs between TNF, BMP1, and BMPR2 genes and the three exposures were statistically significant at the 5% level in relation to colon cancer survival but not after multiple-testing adjustment.
CONCLUSIONS
Adopting a comprehensive biologically informed candidate-pathway approach identified GEI effects on colon cancer. Findings may have important implications for public health and personalized medicine targeting prevention and therapeutic strategies. Findings from this study need to be validated in other studies.
Publication
Journal: Human Gene Therapy
December/3/2014
Abstract
Fetal growth restriction (FGR) occurs in ∼8% of pregnancies and is a major cause of perinatal mortality and morbidity. There is no effective treatment. FGR is characterized by reduced uterine blood flow (UBF). In normal sheep pregnancies, local uterine artery (UtA) adenovirus (Ad)-mediated overexpression of vascular endothelial growth factor (VEGF) increases UBF. Herein we evaluated Ad.VEGF therapy in the overnourished adolescent ewe, an experimental paradigm in which reduced UBF from midgestation correlates with reduced lamb birthweight near term. Singleton pregnancies were established using embryo transfer in adolescent ewes subsequently offered a high intake (n=45) or control intake (n=12) of a complete diet to generate FGR or normal fetoplacental growth, respectively. High-intake ewes were randomized midgestation to receive bilateral UtA injections of 5×10¹¹ particles Ad.VEGF-A165 (n=18), control vector Ad.LacZ (n=14), or control saline (n=13). Fetal growth/well-being were evaluated using serial ultrasound. UBF was monitored using indwelling flowprobes until necropsy at 0.9 gestation. Vasorelaxation, neovascularization within the perivascular adventitia, and placental mRNA expression of angiogenic factors/receptors were examined using organ bath analysis, anti-vWF immunohistochemistry, and qRT-PCR, respectively. Ad.VEGF significantly increased ultrasonographic fetal growth velocity at 3-4 weeks postinjection (p=0.016-0.047). At 0.9 gestation fewer fetuses were markedly growth-restricted (birthweight >2SD below contemporaneous control-intake mean) after Ad.VEGF therapy. There was also evidence of mitigated fetal brain sparing (lower biparietal diameter-to-abdominal circumference and brain-to-liver weight ratios). No effects were observed on UBF or neovascularization; however, Ad.VEGF-transduced vessels demonstrated strikingly enhanced vasorelaxation. Placental efficiency (fetal-to-placental weight ratio) and FLT1/KDR mRNA expression were increased in the maternal but not fetal placental compartments, suggesting downstream effects on placental function. Ad.VEGF gene therapy improves fetal growth in a sheep model of FGR, although the precise mechanism of action remains unclear.
Publication
Journal: Epigenetics
June/1/2016
Abstract
Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children under the age of 15. In addition to genetic aberrations, epigenetic modifications such as DNA methylation are altered in cancer and impact gene expression. To identify epigenetic alterations in ALL, genome-wide methylation profiles were generated using the methylated CpG island recovery assay followed by next-generation sequencing. More than 25,000 differentially methylated regions (DMR) were observed in ALL patients with ∼ 90% present within intronic or intergenic regions. To determine the regulatory potential of the DMR, whole-transcriptome analysis was performed and integrated with methylation data. Aberrant promoter methylation was associated with the altered expression of genes involved in transcriptional regulation, apoptosis, and proliferation. Novel enhancer-like sequences were identified within intronic and intergenic DMR. Aberrant methylation in these regions was associated with the altered expression of neighboring genes involved in cell cycle processes, lymphocyte activation and apoptosis. These genes include potential epi-driver genes, such as SYNE1, PTPRS, PAWR, HDAC9, RGCC, MCOLN2, LYN, TRAF3, FLT1, and MELK, which may provide a selective advantage to leukemic cells. In addition, the differential expression of epigenetic modifier genes, pseudogenes, and non-coding RNAs was also observed accentuating the role of erroneous epigenetic gene regulation in ALL.
Publication
Journal: Investigative Ophthalmology and Visual Science
September/17/2009
Abstract
OBJECTIVE
To determine the expression of blood coagulation factors and thrombin receptors in retinal pigment epithelial (RPE) cells and whether the effects of thrombin on the chemotaxis and the secretion of VEGF are mediated by transactivation of growth factor receptors.
METHODS
Gene expression in acutely isolated and cultured human RPE cells was evaluated by RT-PCR. Alterations in gene expression and secretion of VEGF were determined by real-time RT-PCR and ELISA, respectively. Chemotaxis was examined with a Boyden chamber assay.
RESULTS
RPE cells expressed the mRNA of the protease-activated receptors PAR1 and -3 and of various coagulation factors (III, V, VII, VIII, and X). Thrombin stimulated the expression and secretion of VEGF-A from RPE cells, decreased the expression of VEGFD, and increased the gene expression of VEGFR-1 (FLT1). The effects on the secretion of VEGF-A and the increase in FLT1 expression were mediated by stimulation of the secretion of TGF-beta1 and activation of the TGF-beta activin receptor-like kinase. Thrombin stimulated the chemotaxis of RPE cells, and this effect was mediated by transactivation of the PDGF receptor tyrosine kinase.
CONCLUSIONS
The expression of different coagulation factors suggests that RPE cells provide a procoagulant surface for the formation of thrombin from prothrombin via the extrinsic coagulation pathway. Thrombin stimulates the secretion of VEGF-A, the expression of FLT1, and the chemotaxis of RPE cells via transactivation of TGF-beta and PDGF receptors, respectively.
Publication
Journal: Nature Communications
February/19/2017
Abstract
Formation of organ-specific vasculatures requires cross-talk between developing tissue and specialized endothelial cells. Here we show how developing zebrafish spinal cord neurons coordinate vessel growth through balancing of neuron-derived Vegfaa, with neuronal sFlt1 restricting Vegfaa-Kdrl mediated angiogenesis at the neurovascular interface. Neuron-specific loss of flt1 or increased neuronal vegfaa expression promotes angiogenesis and peri-neural tube vascular network formation. Combining loss of neuronal flt1 with gain of vegfaa promotes sprout invasion into the neural tube. On loss of neuronal flt1, ectopic sprouts emanate from veins involving special angiogenic cell behaviours including nuclear positioning and a molecular signature distinct from primary arterial or secondary venous sprouting. Manipulation of arteriovenous identity or Notch signalling established that ectopic sprouting in flt1 mutants requires venous endothelium. Conceptually, our data suggest that spinal cord vascularization proceeds from veins involving two-tiered regulation of neuronal sFlt1 and Vegfaa via a novel sprouting mode.
Publication
Journal: Reproductive Biology and Endocrinology
July/15/2008
Abstract
BACKGROUND
The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs.
METHODS
Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test.
RESULTS
In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy - and replacing the smooth muscle at term - displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy.
CONCLUSIONS
The demonstration of different angiogenic, hyperpermeability and vasodilator factors in the same cellular protagonists of angiogenesis and invasion in the pregnant guinea-pig, supports the presence of a functional network, and strengthens the argument that this species provides an adequate model to understand human pregnancy.
Publication
Journal: Pharmacogenomics
July/6/2014
Abstract
OBJECTIVE
Besides correlating with prognosis, tumor-driven angiogenesis also seemed able to influence response/resistance to chemotherapy in preclinical models. We examined the role of tumor angiogenesis genotyping in determining clinical outcome in metastatic gastric cancer patients receiving first-line chemotherapy.
METHODS
VEGF-A, VEGF-C, FLT1, KDR and FLT4 genotyping was analyzed in gastric tumors from patients receiving platinum-based first-line chemotherapy.
RESULTS
VEGF-A rs25648 correlated with response rate (partial response: 18% among patients showing the VEGF-A rs25648 CT or TT genotype vs 44% among patients showing the VEGF-A rs25648 C genotype; p = 0.04). At multivariate analysis only VEGF-A rs25648 maintained an independent role in determining median progression-free survival (hazard ratio: 1.65 95% CI: 1.12-2.78) and overall survival (hazard ratio: 1.58, 95% CI: 1.17-2.65).
CONCLUSIONS
VEGF-A rs25648 genotyping may help identify a patient subgroup unlikely to benefit from a first-line, platinum-based combination and potential candidates for alternative therapy choices.
Publication
Journal: Biochemical Journal
February/28/2001
Abstract
Despite much progress in recent years, the precise signalling events triggered by the vascular-endothelial-growth-factor (VEGF) receptors, fms-like tyrosine kinase (Flt1) and kinase insert domain-containing receptor (KDR), are incompletely defined. Results obtained when Flt1 and KDR are individually expressed in fibroblasts or porcine aortic endothelial cells have not been entirely consistent with those observed in other endothelial cells expressing both receptors endogenously. It has also been difficult to demonstrate VEGF-induced phosphorylation of Flt1, which has led to speculation that KDR may be the more important receptor for the mitogenic action of VEGF on endothelial cells. In an attempt to identify physiologically important effectors which bind to KDR, we have screened a yeast two-hybrid mouse embryo library with the cytoplasmic domain of KDR. Here we describe the identification of the adaptor protein, Shc-like protein (Sck), as a binding partner for KDR. We demonstrate that this interaction requires phosphorylation of KDR, and identify the binding site for the Src-homology 2 (SH2) domain as tyrosine-1175 of KDR. We have also shown that the SH2 domain of Sck, but not that of Src-homology collagen protein (Shc), can precipitate phosphorylated KDR from VEGF-stimulated porcine aortic endothelial cells expressing KDR, and that an N-terminally truncated Sck protein can associate with KDR, in a phosphorylation-dependent fashion, when co-expressed in human embryonic kidney 293 cells. Furthermore, we demonstrate that in the two-hybrid assay, both Shc and Sck SH2 domains can associate with the related receptor Flt1.
Publication
Journal: Biochemical and Biophysical Research Communications
August/15/2006
Abstract
Vascular endothelial growth factor-A (VEGF), which binds to both VEGF receptor-1 (Flt1) and VEGFR-2 (KDR/Flk-1), requires nitric oxide (NO) to induce angiogenesis in a cGMP-dependent manner. Here we show that VEGF-E, a VEGFR-2-selective ligand stimulates NO release and tube formation in human umbilical vein endothelial cells (HUVEC). Inhibition of phospholipase Cgamma (PLCgamma) with U73122 abrogated VEGF-E induced endothelial cell migration, tube formation and NO release. Inhibition of endothelial nitric oxide synthase (eNOS) using l-NNA blocked VEGF-E-induced NO release and angiogenesis. Pre-incubation of HUVEC with the soluble guanylate cyclase inhibitor, ODQ, or the protein kinase G (PKG) inhibitor, KT-5823, had no effect on angiogenesis suggesting that the action of VEGF-E is cGMP-independent. Our data provide the first demonstration that VEGFR-2-mediated NO signaling and subsequent angiogenesis is through a mechanism that is dependent on PLCgamma but independent of cGMP and PKG.
Publication
Journal: Journal of Immunology
November/11/2010
Abstract
Vascular endothelial growth factor (VEGF) is a key mediator in the development of airway immune dysfunction to inhaled allergens. However, the exact role of its receptors-mediated signaling is controversial. In this study, we evaluated the role of VEGF receptor (VEGFR)-1- and VEGFR-2-mediated signaling in T cell priming and polarization in the context of inhalation of LPS-containing allergens. A murine asthma model of mixed Th1 and Th17 cell responses was generated using intranasal sensitization with LPS-containing allergens. Pharmacologic intervention was performed during sensitization. In vivo production of VEGF and Th1- and Th17-polarizing cytokines (IL-12p70 and IL-6, respectively) were upregulated by airway exposure to LPS. Pharmacological intervention with a VEGFR-2-neutralizing Ab (anti-Flk1 mAb) abolished the production of IL-6 (but not IL-12p70) and the subsequent development of allergen-specific Th17 cell response. On the other hand, blocking VEGFR-1 signaling with a VEGFR-1 antagonist (anti-Flt1 hexapeptide) did not affect the production of IL-12p70 and IL-6. However, blocking VEGFR-1 signaling resulted in T cell tolerance rather than priming, mainly by inhibiting the maturation of lung dendritic cells, and their migration into lung-draining lymph nodes. These results suggest that T cell priming to LPS-containing allergens depends on VEGFR-1-mediated signaling, and the subsequent Th17 polarization depends on VEGFR-2 signaling.
Publication
Journal: BJOG: An International Journal of Obstetrics and Gynaecology
November/13/2013
Abstract
OBJECTIVE
To analyse the economic and resource implications of using plasma soluble fms-like tyrosine kinase-1 s(Flt1) and placenta growth factor (PlGF) measurements in pre-eclampsia evaluation and management.
METHODS
Retrospective cost analysis of our prospective cohort study.
METHODS
Boston, Massachusetts (USA).
METHODS
Women (n = 176) presenting to the hospital at <34 weeks of gestation for evaluation of possible pre-eclampsia during 2009-10. Cases without complete cost or outcome data (n = 9) and re-enrolments (n = 18) were excluded.
METHODS
Modelled comparisons between the standard approach (combination of blood pressure, urinary protein excretion, alanine aminotransferase and platelet counts) and a novel approach (ratio of plasma sFlt1 and PlGF) using actual hospital data converted to 2012 US dollars in accordance with the Centers for Medicare and Medicaid Services.
METHODS
Direct 2-week costs and resource use by groups having true or false positive and negative test results for adverse outcomes according to approach.
RESULTS
The improved specificity of the novel approach decreased the proportion of women falsely labelled as test-positive from 42.3% (34.4-50.2%) to 4.0% (0.85-7.15%) and increased the proportion correctly labelled as test-negative from 23.5% (16.7-30.3%) to 61.7% (53.9-69.5%). This could potentially reduce average per-patient costs by $1215. Substantial quantities of resources [47.2% (35.7-58.7%) of antenatal admissions and 72.5% (68.0-77.0%) of tests for fetal wellbeing] were unnecessarily used for women who were truly negative. A proportion of iatrogenic preterm deliveries among women with negative results was potentially avoidable representing further cost and resource savings.
CONCLUSIONS
Clinical use of the plasma sFlt1 and PlGF ratio improves risk stratification among women presenting for pre-eclampsia evaluation and has the potential to reduce costs and resource use.
Publication
Journal: Annals of the New York Academy of Sciences
July/11/1999
Abstract
The purpose of this report is to demonstrate the expression of very recently identified surface antigens on CD34+ and AC133+ bone marrow (BM) cells. Coexpression analysis of AC133 and defined antigens on CD34+ BM cells revealed that the majority of the CD164+, CD135+, CD117+, CD38low, CD33+, and CD71low cells resides in the AC133+ population. In contrast, most of the CD10+ and CD19+ B cell progenitors and a fraction of the CD71high population are AC133-, indicating that CD34+AC133+ cells are enriched in primitive and myeloid progenitor cells, whereas CD34+AC133- cells mainly consist of B cell and late erythroid progenitors. This corresponds to the highly reduced percentage of CD10+ B cells and the absence of CD71high erythroid progenitors on AC133+ selected BM cells. A portion of 0.2-0.7% of the AC133+ selected cells do not coexpress CD34. These cells are very small and define a uniform CD71-, CD117-, CD10-, CD38low, CD135+, HLA-DRhigh, CD45+ population with unknown delineation. Four color analysis on CD34+CD38- BM cells revealed that virtually all of these primitive cells express AC133. Using an improved liposome-enhanced labeling technique for the staining of weakly expressed antigens, subsets of this population could be identified which express the angiopoietin receptors TIE (67.6%) and TEK (36.8%), the vascular endothelial growth factor receptors FLT1 (7%), FLT4 (3.2%), and KDR (10.4%), or the receptor tyrosine kinases HER-2 (15.4%) and FLT3 (CD135; 77.6%). Our results suggest that the CD34+CD38- population is heterogeneous with respect to the expression of the analyzed receptor tyrosine kinases.
Publication
Journal: American Journal of Obstetrics and Gynecology
February/18/2010
Abstract
OBJECTIVE
Molar pregnancy is associated with very early-onset preeclampsia. Since excessive circulating antiangiogenic factors may play a pathogenic role in preeclampsia, we hypothesized that molar placentas produce more antiangiogenic proteins than normal placentas.
METHODS
This retrospective case-control study used a semiquantitative immunohistochemical technique to compare histologic sections of molar placentas to normal controls. Tissue slides were treated with 2 antisera: one recognized the antiangiogenic markers fms-like tyrosine kinase receptor 1 (Flt1) and its soluble form (sFlt1), while the other recognized vascular endothelial marker CD31. Stain intensity was graded from 1+ (strong focal staining) to 4+ (91-100% staining).
RESULTS
Molar placentas (n = 19) showed significantly more staining than controls (n = 16) for Flt/sFlt1 (P < .0001).
CONCLUSIONS
There was a significant difference in Flt1/sFlt1 immunostaining intensity when molar placentas were compared to controls. This supports a hypothesis that the phenotype of preeclampsia in molar pregnancy may result from trophoblasts overproducing at least 1 antiangiogenic protein.
Publication
Journal: American Journal of Physiology - Regulatory Integrative and Comparative Physiology
December/9/2013
Abstract
End-tidal breath carbon monoxide (CO) is abnormally low in women with preeclampsia (PE), while women smoking during pregnancy have shown an increase in CO levels and a 33% lower incidence of PE. This effect may be, in part, due to lowered sFLT1 plasma levels in smokers, and perhaps low-level CO inhalation can attenuate the development of PE in high-risk women. Our previous work showed maternal chronic CO exposure (<300 ppm) throughout gestation had no maternal or fetal deleterious effects in mice. Our current study evaluated the uteroplacental vascular effects in CD-1 maternal mice that inhaled CO (250 ppm) both chronically, gestation day (GD) 0.5 to 18.5, and acutely, 2.5 h on each of GD 10.5 and 14.5. We demonstrated, using microultrasound measurements of blood velocity and microcomputed tomography imaging of the uteroplacental vasculature, that chronic maternal exposure to CO doubled uterine artery blood flow and augmented uteroplacental vascular diameters and branching. This finding may be of benefit to women with PE, as they exhibit uteroplacental vascular compromise. The ratio of VEGF protein to its FLT1 receptor was increased in the placenta, suggesting a shift to a more angiogenic state; however, maternal circulating levels of VEGF, sFLT1, and their ratio were not significantly changed. Doppler blood velocities in the maternal uterine artery and fetal umbilical artery and vein were unaltered. This study provides in vivo evidence that chronic inhalation of 250 ppm CO throughout gestation augments uterine blood flow and uteroplacental vascular growth, changes that may protect against the subsequent development of preeclampsia.
Publication
Journal: Biochemical and Biophysical Research Communications
August/5/1996
Abstract
Vascular endothelial growth factor (VEGF) was identified as an endothelial cell specific mitogen that induces angiogenesis and vascular permeability in vivo. VEGF is a homodimeric protein which contains three intramolecular and two intermolecular disulfide bridges. Here, we report on an efficient procedure for recombinant production of VEGF isoforms VEGF121 and VEGF165 in Escherichia coli. The proteins were solubilized from inclusion bodies, refolded, and purified by chromatographic methods. The final protein products were almost completely in the dimeric conformation, bound to VEGF receptor FLT1 with a Kd of 30 pM, stimulated proliferation of human umbilical vein endothelial cells half-maximally at a concentration of 30 pM, and induced in vivo neovascularization and vascular permeability on the chicken chorioallantoic membrane.
Publication
Journal: Pathology and Oncology Research
March/2/2016
Abstract
Preterm preeclampsia is associated with the failure of trophoblast invasion, placental hypoxic/ischemic injury and the release of toxic substances, which promote the terminal pathway of preeclampsia. In term preeclampsia, factors yet unknown trigger the placenta to induce the terminal pathway. The contribution of the villous trophoblast to these pathologic events has not been fully elucidated. Here we aimed to study how stress and signaling pathways influence trophoblastic functions in various subforms of preeclampsia. Tissue microarrays (TMAs) were constructed from placentas obtained from pregnant women in the following groups: 1-2) preterm preeclampsia with (n = 8) or without (n = 7) HELLP syndrome; 3) late-onset preeclampsia (n = 8); 4-5) preterm (n = 5) and term (n = 9) controls. TMA slides were stained for phosphorylated Akt-1, ERK1/2, JNK, and p38 kinases, and trophoblastic immunostainings were semi-quantitatively evaluated. BeWo cells were kept in various stress conditions, and the expression of FLT1, GCM1, LEP, and PGF was profiled by qRT-PCR, while Akt-1, ERK1/2, JNK, and p38 kinase activities were measured with phospho-kinase immunoassays. We found that: 1) Placental LEP and FLT1 expression was up-regulated in preterm preeclampsia with or without HELLP syndrome compared to controls; 2) Mean pp38 immunoscore was higher in preterm preeclampsia, especially in cases with HELLP syndrome, than in controls. 3) Mean pERK1/2 immunoscore was higher in preterm preeclampsia with HELLP syndrome than in controls. 4) In BeWo cells, ischemia up-regulated LEP expression, and it increased JNK and decreased ERK1/2 activity. 5) Hypoxia up-regulated FLT1 and down-regulated PGF expression, and it increased ERK1/2, JNK and p38 activity. 6) IL-1β treatment down-regulated PGF expression, and it increased JNK and p38 activity. 7) The p38 signaling pathway had the most impact on LEP, FLT1 and PGF expression. In conclusion, hypoxic and ischemic stress, along with unknown factors, activates trophoblastic p38 signaling, which has a key role in villous trophoblastic functional changes in preterm preeclampsia. The activation of ERK1/2 signaling may induce additional trophoblastic functional changes in HELLP syndrome, while distinct mechanisms may promote late-onset preeclampsia.
Publication
Journal: Cancer Epidemiology Biomarkers and Prevention
November/6/2013
Abstract
BACKGROUND
Angiogenesis and lymphangiogenesis are important in the progression of melanoma. We investigated associations between genetic variants in these pathways with sentinel lymph node (SLN) metastasis and mortality in 2 independent series of patients with melanoma.
METHODS
Participants at Moffitt Cancer Center were 552 patients, all Caucasian, with primary cutaneous melanoma referred for SLN biopsy. A total of 177 patients had SLN metastasis, among whom 60 died from melanoma. Associations between 238 single-nucleotide polymorphisms (SNP) in 26 genes and SLN metastasis were estimated as ORs and 95% confidence intervals (CI) using logistic regression. Competing risk regression was used to estimate HRs and 95% CI for each SNP and melanoma-specific mortality. We attempted to replicate significant findings using data from a genome-wide association study comprising 1,115 patients with melanoma who were referred for SLN biopsy from MD Anderson Cancer Center (MDACC), among whom 189 patients had SLN metastasis and 92 patients died from melanoma.
RESULTS
In the Moffitt dataset, we observed significant associations in 18 SNPs with SLN metastasis and 17 SNPs with mortality. Multiple SNPs in COL18A1, EGF receptor (EGFR), FLT1, interleukin (IL)-10, platelet-derived growth factor D (PDGFD), PIK3CA, and toll-like receptor (TLR)-3 were associated with the risk of SLN metastasis and/or patient mortality. The MDACC data set replicated an association between mortality and rs2220377 in PDGFD. Furthermore, in a meta-analysis, 3 additional SNPs were significantly associated with SLN metastasis (EGFR rs723526 and TLR3 rs3775292) and melanoma-specific death (TLR3 rs7668666).
CONCLUSIONS
These findings suggest that genetic variation in angiogenesis and lymphangiogenesis contributes to regional nodal metastasis and progression of melanoma.
CONCLUSIONS
Additional research attempting to replicate these results is warranted.
Publication
Journal: PLoS ONE
August/5/2013
Abstract
Chiari malformation type I (CMI) is a disorder characterized by hindbrain overcrowding into an underdeveloped posterior cranial fossa (PCF), often causing progressive neurological symptoms. The etiology of CMI remains unclear and is most likely multifactorial. A putative genetic contribution to CMI is suggested by familial aggregation and twin studies. Experimental models and human morphometric studies have suggested an underlying paraxial mesoderm insufficiency. We performed a case-control association study of 303 tag single nucleotide polymorphisms (SNP) across 58 candidate genes involved in early paraxial mesoderm development in a sample of 415 CMI patients and 524 sex-matched controls. A subgroup of patients diagnosed with classical, small-PCF CMI by means of MRI-based PCF morphometry (n = 186), underwent additional analysis. The genes selected are involved in signalling gradients occurring during segmental patterning of the occipital somites (FGF8, Wnt, and retinoic acid pathways and from bone morphogenetic proteins or BMP, Notch, Cdx and Hox pathways) or in placental angiogenesis, sclerotome development or CMI-associated syndromes. Single-marker analysis identified nominal associations with 18 SNPs in 14 genes (CDX1, FLT1, RARG, NKD2, MSGN1, RBPJ1, FGFR1, RDH10, NOG, RARA, LFNG, KDR, ALDH1A2, BMPR1A) considering the whole CMI sample. None of these overcame corrections for multiple comparisons, in contrast with four SNPs in CDX1, FLT1 and ALDH1A2 in the classical CMI group. Multiple marker analysis identified a risk haplotype for classical CMI in ALDH1A2 and CDX1. Furthermore, we analyzed the possible contributions of the most significantly associated SNPs to different PCF morphometric traits. These findings suggest that common variants in genes involved in somitogenesis and fetal vascular development may confer susceptibility to CMI.
Publication
Journal: Journal of Reproduction and Development
May/17/2017
Abstract
Follicle development is accompanied by proliferation of granulosa cells and increasing oocyte size. To obtain high-quality oocytes in vitro, it is important to understand the processes that occur in oocytes and granulosa cells during follicle development and the differences between in vivo and in vitro follicle development. In the present study, oocytes and granulosa cells were collected from early antral follicles (EAFs, 0.5-0.7 mm in diameter), small antral follicles (SAFs, 1-3 mm in diameter), large antral follicles (LAFs, 3-7 mm in diameter), and in vitro grown oocyte-and-granulosa cell complexes (OGCs), which were cultured for 14 days after collection from EAFs. Gene expression was analyzed comprehensively using the next-generation sequencing technology. We found top upstream regulators during the in vivo follicle development and compared them with those in in vitro developed OGCs. The comparison revealed that HIF1 is among the top regulators during both in vivo and in vitro development of OGCs. In addition, we found that HIF1-mediated upregulation of glycolysis in granulosa cells is important for the growth of OGCs, but the cellular metabolism differs between in vitro and in vivo grown OGCs. Furthermore, on the basis of comparison of upstream regulators between in vivo and in vitro development of OGCs, we believe that low expression levels of FLT1 (VEGFA receptor), SPP1, and PCSK6 can be considered causal factors of the suboptimal development under in vitro culture conditions.
Publication
Journal: Frontiers in Behavioral Neuroscience
April/24/2014
Abstract
The transition to motherhood involves CNS changes that modify sociability and affective state. However, these changes also put females at risk for post-partum depression and psychosis, which impairs parenting abilities and adversely affects children. Thus, changes in expression and interactions in a core subset of genes may be critical for emergence of a healthy maternal phenotype, but inappropriate changes of the same genes could put women at risk for post-partum disorders. This study evaluated microarray gene expression changes in medial prefrontal cortex (mPFC), a region implicated in both maternal behavior and psychiatric disorders. Post-partum mice were compared to virgin controls housed with females and isolated for identical durations. Using the Modular Single-set Enrichment Test (MSET), we found that the genetic landscape of maternal mPFC bears statistical similarity to gene databases associated with schizophrenia (5 of 5 sets) and bipolar disorder (BPD, 3 of 3 sets). In contrast to previous studies of maternal lateral septum (LS) and medial preoptic area (MPOA), enrichment of autism and depression-linked genes was not significant (2 of 9 sets, 0 of 4 sets). Among genes linked to multiple disorders were fatty acid binding protein 7 (Fabp7), glutamate metabotropic receptor 3 (Grm3), platelet derived growth factor, beta polypeptide (Pdgfrb), and nuclear receptor subfamily 1, group D, member 1 (Nr1d1). RT-qPCR confirmed these gene changes as well as FMS-like tyrosine kinase 1 (Flt1) and proenkephalin (Penk). Systems-level methods revealed involvement of developmental gene networks in establishing the maternal phenotype and indirectly suggested a role for numerous microRNAs and transcription factors in mediating expression changes. Together, this study suggests that a subset of genes involved in shaping the healthy maternal brain may also be dysregulated in mental health disorders and put females at risk for post-partum psychosis with aspects of schizophrenia and BPD.
Publication
Journal: Tumor Biology
June/23/2014
Abstract
Preoperative evaluation of the risk for metastases in endometrial carcinoma is challenging. The growth of new vessels, angiogenesis, is important for tumor growth and purported to be involved in the metastatic process. The aim of this study was to evaluate the significance of preoperative serum levels and immunohistochemical expression of angiogenic markers in predicting a metastasized disease. Preoperative sera from 98 consecutive women presenting with endometrial carcinoma were collected. Serum concentrations of VEGF, sFLT1, and CD105 were assessed by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry was used to assess the expression of CD105, VEGF, FLT1, and KDR. The results were correlated to the presence of metastases, presence of deep (≥50%) myometrial invasion, and the histological grade of the tumor. Tumors with other than endometrioid histology were excluded. Of the 80 evaluable patients, 11 had a metastasized disease. The serum concentration of VEGF was higher in the group with metastases than in the group without metastases (median [range], 743 pg/mL [546-1,183 pg/mL] vs. 383 pg/mL [31-1,524 pg/mL], p < 0.001, respectively). In the multivariable analysis, the concentration of VEGF was the sole independent, albeit weak predictive factor for the presence of metastases (odds ratio, 1.004, 95% confidence interval, 1.002-1.007; p = 0.001). The immunohistochemical expression of the markers was not associated with any of the clinicopathological features of the tumors. The results of the present study suggest that preoperative serum VEGF concentration correlates with the presence of metastases in endometrioid endometrial carcinoma.
Publication
Journal: Journal of Cancer
August/17/2015
Abstract
Tumor cells require angiogenesis to deliver nutrients and oxygen to support their fast growth and metabolism. The vascular endothelial growth factor (VEGF) pathway plays an important role in promoting angiogenesis, including tumor-induced angiogenesis. Recent clinical trials have demonstrated the benefit of targeting VEGF in the treatment of glioblastoma. However, the prognostic significance of the expression of VEGFA and its receptors VEGFR1 (FLT1) and VEGFR2 (KDR) are still largely elusive. In the present study, we aimed to investigate the prognostic significance of these three factors, alone or in combination, in glioma patients. Gene mRNA expression was extracted from three independent brain tumor cohorts totaling 242 patients and the association between gene expression and survival was tested. We found that when VEGFA, FLT1 and KDR expressions were considered alone, only VEGFA demonstrated a significant association with patient survival. Patients with high expression of both VEGFA and either receptor had significantly worse survival than patients expressing both factors at a low level. Importantly, we found that those patients whose tumors overexpressed all three genes had a significantly shorter survival compared to those patients with a low level expression of these genes. Our results suggest that a high level expression of VEGFA and its receptors, both FLT1 and KDR, may be required for brain tumor progression, and that these three factors should be considered together as a prognostic indicator for brain tumor patients.
load more...