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This study investigates the hyaloid vascular regression and its relationship to the retinal and choroidal vascular developments using optical coherence tomography angiography (OCTA). Normal and oxygen-induced retinopathy (OIR) rat eyes at postnatal day 15, 18, 21, and 24 were longitudinally imaged using OCTA. At each day, two consecutive imaging for visualizing the hyaloid vasculature and the retinal and choroidal vasculatures were conducted. The hyaloid vessel volume and the retinal and choroidal vessel densities were measured. The hyaloid vessel volumes gradually decreased during the regression, although the OIR eyes exhibited large vessel volumes at all time points. A spatial relationship between persistent hyaloid vasculature and retardation of underlying retinal vascular development was observed in the OIR eyes. Furthermore, anti-vascular endothelial growth factor (VEGF) was administered intravitreally to additional OIR eyes to observe its effect on the vascular regression and development. The VEGF injection to OIR eyes showed reduced persistent hyaloid vessels in the injected eyes as well as in the non-injected fellow eyes. This study presents longitudinal imaging of intraocular vasculatures in the developing eye and shows the utility of OCTA that can be widely used in studies of vascular development and regression and preclinical evaluation of new anti-angiogenic drugs. [ABSTRACT FROM AUTHOR]

To quantitatively understand biological processes that occur over many hours or days, it is desirable to image multiple samples simultaneously and automatically process and analyze the resulting datasets. Here, we present a complete multi-sample preparation, imaging, processing, and analysis workflow to determine the development of the vascular volume in zebrafish. Up to five live embryos were mounted and imaged simultaneously over several days using selective plane illumination microscopy (SPIM). The resulting large imagery dataset of several terabytes was processed in an automated manner on a high-performance computer cluster and segmented with a novel segmentation approach that uses images of red blood cells as training data. This analysis yielded a precise quantification of growth characteristics of the whole vascular network, head vasculature, and tail vasculature over development. Our multi-sample platform demonstrates effective upgrades to conventional single-sample imaging platforms and paves the way for diverse quantitative long-term imaging studies. [ABSTRACT FROM AUTHOR]

Migraine is a severe neurological disorder in which calcitonin gene-related peptide (CGRP) is a key molecule in pathophysiology. Neuronal system-derived CGRP enhances neovascularization in several important pathological conditions and sends a cue to the vascular system. In 2018, the FDA approved erenumab and fremanezumab, antibodies against CGRP receptor and CGRP, as the first new class of drugs for migraine. Treatment of migraine with these antibodies requires great care because neovascularization-related adverse effects may be induced in some patients. Here, we focus on enhancement of neovascularization by CGRP and discuss possible adverse effects resulting from blocking neovascularization. We also suggest that CGRP antibodies may also be used as novel antitumor agents by suppressing tumor-associated angiogenesis. Highlights Vasodilating calcitonin gene-related peptide (CGRP), a key neuropeptide in migraine pathophysiology, exhibits proangiogenic and prolymphangiogenic activities. It also sends a cue for neovascularization to modulate recovery from ischemia, healing ulcers and wounds, and lymph edema, and to enhance tumor-associated angiogenesis and tumor growth. In 2018, the FDA approved CGRP/CGRP receptor antibodies that prevent migraine, representing progress over simple relief therapeutics. Long-term administration of CGRP/CGRP receptor antibodies could possibly induce adverse effects related to suppression of neovascularization. CGRP/CGRP receptor antibodies could also suppress tumor-associated angiogenesis. Therapeutic benefits versus neovascularization-related adverse effects from CGRP antibodies should be carefully evaluated over a long-term clinical trial. [ABSTRACT FROM AUTHOR]

Abstract Therapeutic modulation of angiogenesis is believed to be a prospective powerful treatment strategy to modulate the microcirculation and therefore help millions of patients with cardiovascular and cancer diseases. The often-frustrating results from late-stage clinical studies indicate an urgent need for improved assessment of the pro- and anti-angiogenic compounds in preclinical stage of investigation. For such a proper assessment, detailed vascular visualization and adequate quantification are essential. Nowadays, there are few imaging modalities available, but none of them provides non-destructive 3D-visualization of the vasculature down to the capillary level. In many instances, the approaches cannot be combined with the subsequent histological or ultrastructural analysis. In this review, we address the latest developments in the microvascular imaging, namely, the microangioCT approach with a polymer-based contrast agent (μAngiofil). This approach allows time-efficient non-destructive 3D-imaging of the organ and its vasculature including the finest capillaries. Besides the superior visualization, the obtained detailed 3D information on the organ vasculature enables its 3D-skeletonization and further quantitative analysis. Probably the only significant limitation of the described approach is that it can be used only ex vivo, i.e., no longitudinal studies. In spite of this drawback, microangioCT with μAngiofil is a relatively simple and straightforward tool with a broad application range for studying physiological and pathological alterations in the microvasculature of any organ. It provides microvascular imaging at unprecedented level and enables correlative microscopy. [ABSTRACT FROM AUTHOR]

Abnormal metabolism and uncontrolled angiogenesis are two important characteristics of malignant tumors. The occurrence of both events involves many key molecular changes including miRNA. However, EBV encoded miRNAs are rarely mentioned as capable of regulating tumor metabolism and tumor angiogenesis. Here, we reported that one of the key miRNAs encoded by EBV, EBV-miR-Bart1-5P, can significantly promote nasopharyngeal carcinoma (NPC) cell glycolysis and induces angiogenesis in vitro and in vivo. Mechanistically, EBV-miR-Bart1-5P directly targets the α1 catalytic subunit of AMP-activated protein kinase (AMPKα1) and consequently regulates the AMPK/mTOR/HIF1 pathway which impelled NPC cell anomalous aerobic glycolysis and angiogenesis, ultimately leads to uncontrolled growth of NPC. Our findings provide new insights into metabolism and angiogenesis of NPC and new opportunities for the development of targeted NPC therapy in the future. [ABSTRACT FROM AUTHOR]

Objective: Neovascularization of the aortic wall may be associated with aortic dissection (AD). Aortic wall endothelial CD31 deposition together with chronic inflammation indicates angiogenesis that may lead to tissue disruption. We studied the presence of neovascularization of the ascending aortic wall by characterizing CD31 positive endothelial cells. Methods: Aortic wall routine histology and immunohistochemistry for CD31, T- and B-lymphocytes, plasma cells, macrophages, endothelial cells, smooth muscle cells, and cell proliferation were performed on 35 selected patients who underwent surgery for the ascending aorta, and the samples were grouped according to the presence of AD. Results: Three subjects with Marfan syndrome were excluded from the study. A total of 14 out of 32 patients had AD. A total of 18 patients were operated on due to dilatation only. Chronic inflammation of the adventitia (p=0.003), media (p=0.001), and intima (p=0.005) was increased in AD. Neovascularization was predominant in the outer third medial layer in AD (p=0.037), corresponding to the site of aortic wall disruption. A receiver operating characteristic curve analysis showed that neovascularization was associated with AD (AUC 0.750; SE 0.092; p=0.022; 95% CI 0.570-0.930). Conclusion: Endothelial immunohistochemistry confirms neovascularization of the outer third medial layer during AD. Aortic wall remodeling including neovascularization characterizes AD. Chronic inflammation and neovascularization of the dilated ascending aorta suggest susceptibility for AD. [ABSTRACT FROM AUTHOR]

The bone morphogenetic protein (BMP) signaling pathway plays a central role during vasculature development. Mutations or dysregulation of the BMP pathway members have been linked to arteriovenous malformations. In the present study, we investigated the effect of the BMP modulators bone morphogenetic protein endothelial precursor‐derived regulator (BMPER) and twisted gastrulation protein homolog 1 (TWSG1) on arteriovenous specification during zebrafish development and analyzed downstream Notch signaling pathway in human endothelial cells. Silencing of bmper and twsg1b in zebrafish embryos by morpholinos resulted in a pronounced enhancement of venous ephrinB4a marker expression and concomitant dysregulated arterial ephrinb2a marker expression detected by in situ hybridization. As arteriovenous specification was disturbed, we assessed the impact of BMPER and TWSG1 protein stimulation on the Notch signaling pathway on endothelial cells from different origin. Quantitative real‐time PCR (qRT‐PCR) and western blot analysis showed increased expression of Notch target gene hairy and enhancer of split, HEY1/2 and EPHRINB2. Consistently, silencing of BMPER in endothelial cells by siRNAs decreased Notch signaling and downstream effectors. BMP receptor antagonist DMH1 abolished BMPER and BMP4 induced Notch signaling pathway activation. In conclusion, we found that in endothelial cells, BMPER and TWSG1 are necessary for regular Notch signaling activity and in zebrafish embryos BMPER and TWSG1 preserve arteriovenous specification to prevent malformations. [ABSTRACT FROM AUTHOR]

Objective: The study aimed to systematically review the association between angiogenesis and clinicopathological characteristics and its prognostic value in patients with endometrial cancer.Methods: Eligible studies were searched in PubMed, Embase, China National Knowledge Infrastructure, and Wanfang database. Studies that assessed blood microvessel density (BMVD) and correlated with clinicopathological features and/or overall survival (OS) were included. Geometric mean values and hazard ratio with 95% confidence interval were pooled to examine the risk or hazard association. Subgroup analyses were conducted based on populations, BMVD criteria, BMVD markers, and type of survival analysis.Results: A total of 29 studies of 2517 patients were included. BMVD was associated with depth of myometrial invasion (MI) [standard mean difference (SMD) 1.24; 95% CI 0.53-1.95; P = 0.0006], lymphovascular space invasion (LVSI) (SMD 0.75; 95% CI 0.3-1.21; P = 0.001), and lymph node metastasis (LNM) (SMD 0.99; 95% CI 0.46-1.52; P = 0.0003). BMVD was also significantly associated with poor OS (HR 2.65; 95% CI 1.86-3.77; P < 0.00001). The association remained significant in the subgroups Asian population, BMVD criteria using Weidner method, BMVD marker CD34 for MI, LVSI, and LNM, CD105 for MI, and factor VIII for MI and LNM, respectively. For OS, either Asian or non-Asian population, BMVD criteria using Weidner or non-Weidner method, BMVD marker CD31, or factor VIII antibody and analysis using univariate or multivariate were all significantly associated.Conclusions: BMVD was associated with deeper MI, positive LVSI, positive LNM, and poor OS in patients with endometrial cancer. Therefore, angiogenesis is a useful measure for poor clinicopathological outcomes and prognosis in patients with endometrial cancer. [ABSTRACT FROM AUTHOR]

We derive a Cahn-Hilliard-Darcy model to describe multiphase tumour growth taking interactions with multiple chemical species into account as well as the simultaneous occurrence of proliferating, quiescent and necrotic regions. A multitude of phenomena such as nutrient diffusion and consumption, angiogenesis, hypoxia, blood vessel growth, and inhibition by toxic agents, which are released for example by the necrotic cells, are included. A new feature of the modelling approach is that a volume-averaged velocity is used, which dramatically simplifies the resulting equations. With the help of formally matched asymptotic analysis we develop new sharp interface models. Finite element numerical computations are performed and in particular the effects of necrosis on tumour growth are investigated numerically. In particular, for certain modelling choices, we obtain some form of focal and patchy necrotic growth that have been observed in experiments. [ABSTRACT FROM AUTHOR]

Formation of blood vessel networks by sprouting angiogenesis is critical for tissue growth, homeostasis and regeneration. How endothelial cells arise in adequate numbers and arrange suitably to shape functional vascular networks is poorly understood. Here we show that YAP/TAZ promote stretch-induced proliferation and rearrangements of endothelial cells whilst preventing bleeding in developing vessels. Mechanistically, YAP/TAZ increase the turnover of VE- Cadherin and the formation of junction associated intermediate lamellipodia, promoting both cell migration and barrier function maintenance. This is achieved in part by lowering BMP signalling. Consequently, the loss of YAP/TAZ in the mouse leads to stunted sprouting with local aggregation as well as scarcity of endothelial cells, branching irregularities and junction defects. Forced nuclear activity of TAZ instead drives hypersprouting and vascular hyperplasia. We propose a new model in which YAP/TAZ integrate mechanical signals with BMP signaling to maintain junctional compliance and integrity whilst balancing endothelial cell rearrangements in angiogenic vessels. [ABSTRACT FROM AUTHOR]

The prolactin/vasoinhibin axis defines an endocrine system, in which prolactin (PRL) and vasoinhibins regulate blood vessel growth and function, the secretion of other hormones, inflammatory and immune processes, coagulation, and behavior. The core element of the PRL/vasoinhibin axis is the generation of vasoinhibins, which consists in the proteolytic cleavage of their precursor molecule PRL. Vasoinhibins can interact with multiple different partners to mediate their effects in various tissues and anatomical compartments, indicating their pleiotropic nature. Based on accumulating knowledge about the PRL/vasoinhibin axis, two clinical trials were initiated, in which vasoinhibin levels are the target of therapeutic interventions. One trial investigates the effect of levosulpiride, a selective dopamine D2-receptor antagonist, on retinal alterations in patients with diabetic macular edema and retinopathy. The rationale of this trial is that the levosulpiride-induced hyperprolactinemia resulting in increased retinal vasoinhibins could lead to beneficiary outcomes in terms of a vasoinhibin-mediated antagonization of diabetes-induced retinal alterations. Another trial investigated the effect of bromocriptine, a dopamine D2-receptor agonist, for the treatment of peripartum cardiomyopathy. The rationale of treatment with bromocriptine is the inhibition of vasoinhibin generation by substrate depletion to prevent detrimental effects on the myocardial microvascularization. The trial demonstrated that bromocriptine treatment was associated with a high rate of left ventricular recovery and low morbidity and mortality. Therapeutic interventions into the PRL/vasoinhibin axis bear the risk of side effects in the areas of blood coagulation, blood pressure, and alterations of the mental state. [ABSTRACT FROM AUTHOR]

Recent approaches in tissue regeneration focus on combining innovative achievements of stem cell biology and biomaterial sciences to develop novel therapeutic strategies for patients. Growing recent evidence indicates that mesenchymal stem cells harvested from human umbilical cord Wharton's jelly (hUC-MSCs) are a new valuable source of cells for autologous as well as allogeneic therapies in humans. hUC-MSCs are multipotent, highly proliferating cells with prominent immunoregulatory activity. In this study, we evaluated the impact of widely used FDA approved poly(α-esters) including polylactide (PLA) and polycaprolactone (PCL) on selected biological properties of hUC-MSCs in vitro . We found that both polymers can be used as non-toxic substrates for ex vivo propagation of hUC-MSCs as shown by no major impact on cell proliferation or viability. Moreover, PCL significantly enhanced the migratory capacity of hUC-MSCs. Importantly, genetic analysis indicated that both polymers promoted the angiogenic differentiation potential of hUC-MSCs with no additional chemical stimulation. These results indicate that PLA and PCL enhance selected biological properties of hUC-MSCs essential for their regenerative capacity including migratory and proangiogenic potential, which are required for effective vascular repair in vivo . Thus, PLA and PCL-based scaffolds combined with hUC-MSCs may be potentially employed as future novel grafts in tissue regeneration such as blood vessel reconstruction. [ABSTRACT FROM AUTHOR]

The lymphatic vascular system is a hierarchically organized complex network essential for tissue fluid homeostasis, immune trafficking and absorption of dietary fats in the human body. Despite its importance, the assembly of the lymphatic network is still not fully understood. The zebrafish is a powerful model organism that enables study of lymphatic vessel development using high-resolution imaging and sophisticated genetic and experimental manipulation. Although several studies have described early lymphatic development in the fish, lymphatic development at later stages has not been completely elucidated. In this study, we generated a new Tg(mrc1a:egfp)y251 transgenic zebrafish that uses a mannose receptor, C type 1 (mrc1a) promoter to drive strong EGFP expression in lymphatic vessels at all stages of development and in adult zebrafish. We used this line to describe the assembly of the major vessels of the trunk lymphatic vascular network, including the later-developing collateral cardinal, spinal, superficial lateral and superficial intersegmental lymphatics. Our results show that major trunk lymphatic vessels are conserved in the zebrafish, and provide a thorough and complete description of trunk lymphatic vessel assembly. [ABSTRACT FROM AUTHOR]

Aims Angiogenesis is a physiological process that has important impacts on the pathology and healing of various diseases, and its induction or inhibition by bioactive actinobacterial metabolites can help the treatment of some diseases. In this study, the effects of actinobacterial extract in the process of angiogenesis have been explored. Methods and Results In this research, proangiogenic and antiangiogenic metabolites producing actinobacteria were isolated from soil samples and their fermentation broth were extracted and after evaluation of their toxicity by MTT assay, antiangiogenic and proangiogenic activities were screened against human umbilical vein endothelial cells ( HUVECs) by in vitro tube formation and migration assay. Isolated strains were identified through molecular techniques. The results showed that Nocardiopsis arvandica UTMC 103 and Nonomuraea sp. UTMC 2180 extracts had a high potential of anti-angiogenic activity on HUVECs. Conclusions For the first time proangiogenic potency of a rare actinobacterium, Kribbella sp. UTMC 522, was reported, and N. arvandica UTMC 103 and Nonomuraea sp. UTMC 2180 extracts inhibits the proliferation, migration and angiogenesis activity of HUVECs with reasonable potency. Significance and Impact of the Study Metabolites of the introduced rare actinobacteria are potent proangiogenic and angiogenic inhibitors. Identification of angiogenic-antiangiogenic mechanisms and purification of the extracts would be useful in therapeutic angiogenesis. [ABSTRACT FROM AUTHOR]

The Notch pathway is a contact-dependent, or juxtacrine, signaling system that is conserved in metazoan organisms and is important in many developmental processes. Recent investigations have demonstrated that the Notch pathway is active in both the embryonic and postnatal ovary and plays important roles in events including follicle assembly and growth, meiotic maturation, ovarian vasculogenesis and steroid hormone production. In mice, disruption of the Notch pathway results in ovarian pathologies affecting meiotic spindle assembly, follicle histogenesis, granulosa cell proliferation and survival, corpora luteal function and ovarian neovascularization. These aberrations result in abnormal folliculogenesis and reduced fertility. The knowledge of the cellular interactions facilitated by the Notch pathway is an important area for continuing research, and future studies are expected to enhance our understanding of ovarian function and provide critical insights for improving reproductive health. This review focuses on the expression of Notch pathway components in the ovary, and on the multiple functions of Notch signaling in follicle assembly, maturation and development. We focus on the mouse, where genetic investigations are possible, and relate this information to the human ovary. [ABSTRACT FROM AUTHOR]

Background There is increasing interest in the development of vessel substitutes, and many studies are currently focusing on the development of biodegradable scaffolds capable of fostering vascular regeneration. We tested a new biocompatible and biodegradable material with mechanical properties similar to those of blood vessels. Methods The material used comprises a mixture of α,β-poly( N -2-hydroxyethyl)- d,l -aspartamide (PHEA) and polylactic acid (PLA), combined with polycaprolactone (PCL) by means of electrospinning technique. Low-molecular-weight heparin was also linked to the copolymer. A tubular PHEA-PLA/PCL sample was used to create an arteriovenous fistula in a pig model with the use of the external iliac vessels. The flow was assessed by means of Doppler ultrasound examination weekly, and 1 month after the implantation we removed the scaffold for histopathologic evaluation. Results The implants showed a perfect leak-proof seal and adequate elastic tension to blood pressure. About ∼3 weeks after the implantation, Doppler examination revealed thrombosis of the graft, so we proceeded to its removal. Histologic examination showed chronic inflammation, with the presence of foreign body cells and marked neovascularization. The material had been largely absorbed, leaving some isolated spot residues. Conclusions The biocompatibility of PHEA-PLA/PCL and its physical properties make it suitable for the replacement of vessels. In the future, the possibility of functionalizing the material with a variety of molecules, to modulate the inflammatory and coagulative responses, will allow obtaining devices suitable for the replacement of native vessels. [ABSTRACT FROM AUTHOR]

The inhibition of inflammation-associated angiogenesis ameliorates inflammatory diseases by reducing the recruitment of tissue infiltrating leukocytes. However, it is not known if angiogenesis has an active role during the initiation of inflammation or if it is merely a secondary effect occurring in response to stimuli by tissue infiltrating leukocytes. Here we show that angiogenesis precedes leukocyte infiltration in experimental models of inflammatory bowel disease and acute graft-versus-host disease (GVHD). We found that angiogenesis occurred as early as day+2 after allogeneic transplantation mainly in GVHD typical target organs skin, liver and intestines whereas no angiogenic changes appeared due to conditioning or syngeneic transplantation. The initiation phase of angiogenesis was not associated to classical endothelial cell (EC) activation signs, such as Vegfa/VEGFR1+2 upregulation or increased adhesion molecule expression. During early GVHD at day+2, we found significant metabolic and cytoskeleton changes in target organ ECs in gene array- and proteomic analyses. These modifications have significant functional consequences as indicated by profoundly higher deformation in Real-time deformability cytometry. Our results demonstrate that metabolic changes trigger alterations in cell mechanics leading to enhanced migratory and proliferative potential of ECs during the initiation of inflammation. Our study adds evidence to the hypothesis that angiogenesis is involved in the initiation of tissue inflammation during GVHD. [ABSTRACT FROM AUTHOR]

Kokartus honorariusfrom the Middle Jurassic (Bathonian) of Kyrgyzstan is one of the oldest and basalmost salamanders in the fossil record, and this taxon is useful for documenting a primitive caudate condition and patterns of character state transformations within Caudata. Here, we provide a histological analysis of its dermal bones based on two thin sections of a fragment of a sculptured dermal skull roof bone (squamosal?). The dermal bone histology ofKokartusis similar to that of basal crown-group tetrapods (e.g. temnospondyls, lepospondyls and seymouriamorphs) in the following features: the presence of basic pattern of organisation of dermal bones (diploë structure); the cancellous middle region occupies larger space than the compact cortices; active remodelling with the formation of numerous erosion bays and secondary osteons; high number of vascular canals with the formation a dense vascular network (= ‘rete vasculosum’); and parallel-fibred bone is a dominant type of primary bone matrix. Crown-group salamanders retained the diploë structure, but demonstrate features of simplification (in comparison withKokartus): absence of pronounced sculpture, lower degree of vascularisation and lower degree of remodelling. The simplification of the histological structure is a derived feature for the Caudata which appeared during the transition from stem-group to crown-group salamanders. [ABSTRACT FROM PUBLISHER]

Purpose: The aim of this study was to determine the correlation between the duration of myopic choroidal neovascularization (CNV) and treatment outcome after anti-vascular endothelial growth factor (VEGF) injections. Methods: We performed a retrospective review of treatment-naïve myopic CNV patients who were treated with anti-VEGF and followed for at least 24 months to identify factors predicting final outcome and recurrence. Results: Among 106 eyes, a shorter duration of CNV was a significant predictor of a better final bestcorrected visual acuity, even after controlling for other factors (p = 0.042). When divided into 3 groups according to CNV duration before treatment (<2, 2-8, and 8-24 weeks), the recurrence rate (19, 25, and 52%, respectively; p = 0.006) and number of injections (3.5, 4.0, and 5.5, respectively; p = 0.021) were significantly lower in eyes with a shorter duration of CNV. Conclusions: Early anti-VEGF treatment of myopic CNV decreased the recurrence rate and number of injections and improved visual outcome. [ABSTRACT FROM AUTHOR]

Genetic signaling and redox homeostasis are required for proper growth of blood vessels. Here, we report a novel function of peroxiredoxin1 (Prdx1) in vascular development in zebrafish. Knockdown of prdx1 impairs the growth of intersegmental vessel and caudal vein plexus (CVP), and reduces the expression of vascular markers, thus suggesting a role for prdx1 in vasculature and indicating that the antioxidant function of prdx1 is important. We found that H2O2-treated embryos also have CVP defects and observed synergistic effects when prdx1 knockdown was combined with H2O2 treatment. Moreover, N-acetyl-cysteine treatment rescues the vascular defects in prdx1 morphants. These results suggest that oxidative stress disturbs vascularization. Furthermore, we show that the regulation of prdx1 is mediated by Notch and BMP signals. [ABSTRACT FROM AUTHOR]

Background/aim: The role of angiogenic factors in gastric cancer is not clear. We aimed to assess the role of vascular endothelial growth factor A (VEGFA), angiopoietin 1 (Ang-1), and placental growth factor (PlGF) in the prognosis of patients with advanced gastric cancer. Materials and methods: Thirty consecutive patients treated with a modified DCF (docetaxel, cisplatin, and fluorouracil) regimen were included in the study. The plasma VEGFA, Ang-1, and PlGF levels of the patients before treatment and following two cycles of chemotherapy were measured and evaluated as prognostic factors. Results: Poor performance status and lower Ang-1 levels were correlated with poor overall survival (OS). No significant correlation between VEGFA or PlGF and OS was found. An angiogenesis prognostic index (API) based on the levels of VEGFA, Ang-1, and PlGF was found to be highly correlated with OS. Performance status and API were found as independent prognostic factors for OS. Furthermore, a decrease in VEGFA by 25% from the pretreatment level was also found as a prognostic factor for OS independent of response to DCF regimen. Conclusion: Our results support the use of the new API including VEGFA, Ang-1, and PlGF levels in patients with advanced gastric cancer as a predictor of survival. [ABSTRACT FROM AUTHOR]

Purpose To study visual outcome and number of annual injections in treatment-naïve patients with neovascular age-related macular degeneration ( nAMD) before and after a change in first-line therapy from ranibizumab to aflibercept in a high-volume clinical practice. Methods This was a retrospective chart review of routine clinical practice. The study included 1027 treatment-naïve patients, 559 of whom started intravitreal ranibizumab therapy in 2011-2012 and 468 of whom started intravitreal aflibercept therapy in 2013-2014, a fixed loading dose of three injections followed by a pro re nata treatment regimen used in both periods. Results Snellen best-corrected visual acuity ( BCVA) at baseline and after one year was 0.23 and 0.31 (p < 0.0001), respectively, for patients treated with ranibizumab and 0.25 and 0.33 (p < 0.0001) for patients treated with aflibercept, last observation carried forward. The share of patients (73%) still in treatment with ranibizumab at year 1 had a baseline BCVA of 0.26 but 0.40 at year 1 (p < 0.0001), and the patients (75%) still in treatment with aflibercept at year 1 had a baseline BCVA of 0.28 but 0.42 at year 1 (p < 0.0001). Proportional visual gains for both cohorts were comparable for one year (p = 0.14). The number of injections given within year 1 including first injection was 6.9 for ranibizumab and 5.9 for aflibercept (p < 0.0001). In patients continuing treatment through year 1, the number of injections was 8.0 for ranibizumab and 6.6 for aflibercept (p < 0.0001). The two cohorts had similar cause-of-discontinuation profiles. Conclusion Treatment of nAMD at a single centre in two sequential cohorts yielded comparable BCVA outcomes with 15% fewer injections of aflibercept compared to ranibizumab. [ABSTRACT FROM AUTHOR]

Maternal vascular adaptation to pregnancy is critically important to expand the capacity for blood flow through the uteroplacental unit to meet the needs of the developing fetus. Failure of the maternal vasculature to properly adapt can result in hypertensive disorders of pregnancy such as preeclampsia (PE). Herein, we review the endocrinology of maternal adaptation to pregnancy and contrast this with that of PE. Our focus is specifically on those hormones that directly influence endothelial cell function and dysfunction, as endothelial cell dysfunction is a hallmark of PE. A variety of growth factors and cytokines are present in normal vascular adaptation to pregnancy. However, they have also been shown to be circulating at abnormal levels in PE pregnancies. Many of these factors promote endothelial dysfunction when present at abnormal levels by acutely inhibiting key Ca2+ signaling events and chronically promoting the breakdown of endothelial cell-cell contacts. Increasingly, our understanding of how the contributions of the placenta, immune cells, and the endothelium itself promote the endocrine milieu of PE is becoming clearer. We then describe in detail how the complex endocrine environment of PE affects endothelial cell function, why this has contributed to the difficulty in fully understanding and treating this disorder, and how a focus on signaling convergence points of many hormones may be a more successful treatment strategy. [ABSTRACT FROM AUTHOR]

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Peptide ligands consisting of l -amino acids are subject to proteolysis in vivo . When modified on the surface of nanocarriers, those peptide ligands would readily degrade and the targeting efficacy is significantly attenuated. It has received increasing scrutiny to design stable peptide ligands for targeted drug delivery. Here, we present the design of a stable peptide ligand by the formation of a head-to-tail amide bond as an example. Even though the linear l -peptide A7R (termed L A7R) can bind specifically to vascular endothelial growth factor receptor 2 (VEGFR2) and neuropilin-1 (NRP-1) that are overexpressed on glioma cells, neovasculature and glioma vasculogenic mimicry (VM), the tumor-homing capacity of L A7R is greatly impaired in vivo due to proteolysis ( e.g. in the serum). A cyclic A7R (cA7R) peptide was identified by computer-aided peptide design and synthesized with high yield by combining solid phase peptide synthesis and native chemical ligation. The binding of cA7R to both receptors was theoretically and experimentally assessed. In our simulated model hydrophobic and ionic interactions dominated the binding of L A7R to receptors. It is very interesting that cA7R adopting a different structure from L A7R retained high binding affinities to receptors without affecting the hydrophobic and ionic interactions. After head-to-tail cyclization by the formation of an amide bond, cA7R exhibited exceptional stability in mouse serum. Either cA7R or L A7R was conjugated on the surface of doxorubicin (DOX) loaded liposomes (cA7R-LS/DOX or L A7R-LS/DOX). The results of in vitro cellular assays indicated that cA7R-LS/DOX not only displayed stronger anti-proliferative effect against glioma cells, but also demonstrated to be more efficient in destruction of VM and HUVEC tubes in comparison to L A7R-LS/DOX and plain liposomes (LS/DOX, without peptide conjugation). cA7R conjugation could achieve significantly higher accumulation of liposomes in glioma than did L A7R conjugation, which in turn, cA7R-LS/DOX could substantially suppress subcutaneous tumor growth when compared with other DOX formulations (free DOX, LS/DOX and L A7R-LS/DOX). The designed cyclic A7R exhibited the capability of targeting glioma cells, neovasculature and VM simultaneously in vivo . Considering the ease of synthesis, high binding affinity to receptors and increased stability of cA7R peptide in the present study, the design of head-to-tail cyclized peptides by the formation of amide bond based on computer-aided peptide design presents an alternative method to identify proteolytically stable peptide ligands. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether common genetic variants in the endothelial nitric oxide synthase gene (eNOS) are associated with neovascular age-related macular degeneration (nAMD) and polypoidal choroidalvasculopathy (PCV) in a Chinese Han population. Methods: DNA samples were obtained from 157 nAMD patients, 250 PCV patients and 204 healthy control subjects. Tag single nucleotide polymorphisms (SNPs) across the extendedeNOSregion were selected using data derived from the HapMap project. Genotyping of each tag SNP was performed by Multiplex SNaPshot system and direct DNA sequencing techniques. Genotypes and allele frequencies were evaluated with PLINK software for each group. Results: Seven SNPs foreNOS, rs1799983, rs1800783, rs3918186, rs3800787, rs3918188, rs7830, and rs3918227, were chosen as tag SNPs. Among these tag SNPs, rs1800783, rs3918186, rs3918188, and rs3918227 were not associated with nAMD or PCV. Rs1799983, rs3800787, and rs7830 was significantly associated with nAMD (p= 0.0192, 0.0170, and 0.0164, respectively), but not associated with PCV (p= 0.4852, 0.4568, and 0.4014, respectively). The discovered associations were no longer significant after Bonferroni correction. Conclusions: We found no sufficient evidence to support the role of any commoneNOSvariants in the susceptibility to nAMD or PCV in a Chinese Han population. [ABSTRACT FROM AUTHOR]

Background Vascular modifications occur early in the development of psoriasis, and angiogenesis is one of the key features in the pathogenesis of the disease. Objectives To identify the role of the S100 protein psoriasin in psoriasis-associated angiogenesis. Methods The role of psoriasin in mediating angiogenesis was investigated by silencing psoriasin with small interfering RNA (si RNA) and measuring psoriasis-associated angiogenic factors in human epidermal keratinocytes. The secretion of psoriasin and the effect of psoriasin on general regulators of angiogenesis in keratinocytes, and on endothelial cell migration, proliferation, tube formation and production of angiogenic mediators, was evaluated. Results Reactive oxygen species ( ROS) and hypoxia induced the expression of psoriasin. Downregulation of psoriasin in keratinocytes using si RNA altered the ROS-induced expression of the psoriasis-associated angiogenic factors vascular endothelial growth factor ( VEGF), heparin-binding epidermal growth factor-like growth factor, matrix metalloproteinase 1 and thrombospondin 1. Overexpression of psoriasin altered several regulators of angiogenesis and led to the secretion of psoriasin. Treatment with extracellular psoriasin induced proliferation, migration and tube formation in dermal-derived endothelial cells to a similar extent as VEGF and interleukin-17, and induced the expression and release of proangiogenic mediators. These effects were suggested to be mediated by the PI3K and nuclear factor kappa B pathways. Conclusions These findings suggest that psoriasin expression is promoted by oxidative stress in keratinocytes and amplifies the ROS-induced expression of angiogenic factors relevant to psoriasis. Moreover, extracellularly secreted psoriasin may act on dermal endothelial cells to contribute to key features angiogenesis. [ABSTRACT FROM AUTHOR]

Transient receptor potential vanilloid type 1 (TRPV1) is a major nociceptive ion channel implicated in bladder physiology and/or pathophysiology. However, the precise expression of TRPV1 in neuronal vs. nonneuronal bladder cells is uncertain. Here we used reporter mouse lines (TRPV1-Cre: tdTomato and TRPV1PLAP-nlacZ) to map expression of TRPV1 in postnatal bladder. TRPV1 was not detected in the urothelium, however, we found marked expression of TRPV1 lineage in sensory nerves, and surprisingly, in arterial/arteriolar smooth muscle (ASM) cells. Tomato fluorescence was prominent in the vesical arteries and in small-diameter (15-40 µm) arterioles located in the suburothelial layer with a near equal distribution in bladder dome and base. Notably, arteriolar TRPV1 expression was greater in females than in males and increased in both sexes after 90 days of age, suggesting sex hormone and age dependency. Analysis of whole bladder and vesical artery TRPV1 mRNA revealed a similar sex and developmental dependence. Pharmacological experiments confirmed functional TRPV1 protein expression; capsaicin increased intracellular Ca2+ in ~15% of ASM cells from wild-type female bladders, but we observed no responses to capsaicin in bladder arterioles isolated from TRPV1- null mice. Furthermore, capsaicin triggered arteriole constriction that was rapidly reversed by the TRPV1 antagonist, BCTC. These data show that predominantly in postpubertal female mice, bladder ASM cells express functional TRPV1 channels that may act to constrict arterioles. TRPV1 may therefore play an important role in regulating the microcirculation of the female bladder, and this effect may be of significance during inflammatory conditions. [ABSTRACT FROM AUTHOR]

Background Betalains, which are red-purple and yellow pigments, are ideal alternatives to synthetic colorants as they possess strong coloring potential and excellent health-contributing properties. However, the instability of betalains toward normal storage and biological conditions, in addition to the limited number of betalain sources, impedes their food application and diminishes their bioactivities. This study aimed to evaluate the health-promoting bioactivities of betalains from red dragon fruit ( Hylocereus polyrhizus (Weber) Britton and Rose) peels as affected by encapsulation in maltodextrin-gum Arabic and maltodextrin-pectin matrices. Results Encapsulation in maltodextrin-gum Arabic and maltodextrin-pectin matrices afforded dry betalain powders after lyophilization. Optical microscopy imaging showed that the betalain powders consisted of matrix-type and shard-like microparticles. ABTS antioxidant assay revealed that maltodextrin-gum Arabic-betalain ( MGB) and maltodextrin-pectin-betalain ( MPB) microparticles possessed higher antioxidant capacities (195.39 ± 8.63 and 201.76 ± 4.06 µmol Trolox g−1 microparticles respectively) than the non-encapsulated betalain extract (151.07 ± 2.57 µmol Trolox g−1 extract). Duck embryo chorioallantoic membrane ( CAM) vascular irritation assay showed that the anti-inflammatory activity of encapsulated betalains was five- to six-fold higher than that of non-encapsulated betalains ( P ≤ 0.05). Antiangiogenic activity, as evaluated by duck embryo CAM assay, was enhanced two- to four-fold by carbohydrate encapsulation. Glutathione S-transferase ( GST)-inducing activity of betalains was likewise improved four- to five-fold. Conclusion The study showed that the antioxidant, anti-inflammatory, antiangiogenic and GST-inducing activities of betalains from red dragon fruit peels were enhanced through carbohydrate encapsulation. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

cAMP-dependent protein kinase A (PKA) is a ubiquitously expressed serine/threonine kinase that regulates a variety of cellular functions. Here, we demonstrate that endothelial PKA activity is essential for vascular development, specifically regulating the transition from sprouting to stabilization of nascent vessels. Inhibition of endothelial PKA by endothelial cell-specific expression of dominant-negative PKA in mice led to perturbed vascular development, hemorrhage and embryonic lethality at mid-gestation. During perinatal retinal angiogenesis, inhibition of PKA resulted in hypersprouting as a result of increased numbers of tip cells. In zebrafish, cell autonomous PKA inhibition also increased and sustained endothelial cell motility, driving cells to become tip cells. Although these effects of PKA inhibition were highly reminiscent of Notch inhibition effects, our data demonstrate that PKA and Notch independently regulate tip and stalk cell formation and behavior. [ABSTRACT FROM AUTHOR]

Lymphatic vessels have historically been viewed as passive conduits for fluid and immune cells, but this perspective is increasingly being revised as new functions of lymphatic vessels are revealed. Emerging evidence shows that lymphatic endothelium takes an active part in immune regulation both by antigen presentation and expression of immunomodulatory genes. In addition, lymphatic vessels play an important role in uptake of dietary fat and clearance of cholesterol from peripheral tissues, and they have been implicated in obesity and arteriosclerosis. Lymphatic vessels within different organs and in different physiological and pathological processes show a remarkable plasticity and heterogeneity, reflecting their functional specialization. In addition, lymphatic endothelial cells (LECs) of different organs were recently shown to have alternative developmental origins, which may contribute to the development of the diverse lymphatic vessel and endothelial functions seen in the adult. Here, we discuss recent developments in the understanding of heterogeneity within the lymphatic system considering the organ-specific functional and molecular specialization of LECs and their developmental origin. [ABSTRACT FROM AUTHOR]

Engineered tissues need a vascular network to supply cells with nutrients and oxygen after implantation. A network that can connect to the vasculature of the patient after implantation can be included during in vitro culture. For optimal integration, this network needs to be highly organized, including venules, capillaries, and arterioles, to supply all of the cells with sufficient nutrients. Owing to the importance of vascularization for the clinical applicability of tissue engineering, many approaches have been investigated to include an organized vascular network in tissue constructs. This review will give an overview of recent efforts, and will propose future perspectives to engineer the optimal, functional vascular network. [ABSTRACT FROM AUTHOR]

Angiogenesis, the formation of new blood-vessel, is crucial in the pathogenesis of several diseases, and thus represents a druggable target for the prevention and treatment of different disorders. It is nowadays well kwon how diet can control cancer development and progression, and how the use of certain diet components can prevent cancer development. Several studies, also from our lab, now indicate that natural plant products including nutraceuticals modulate tumor angiogenesis. In this review, it is reported how phytochemicals, comprising hydroxytyrosol, resveratrol, genistein, curcumin, and the green tea component epigallocatechin-3-gallate among the others, negatively regulate angiogenesis. A single plant-derived compound may affect both endothelial and tumor cells, with the common denominator of anti-inflammatory and radical scavenger activities. Beside these positive features, documented in cellular and animal models, a series of critical issues should be considered from a pharmacological point of view as: what is the best source of bioactive compounds: food and beverages, extracted phytocomplexes, isolated nutraceuticals or synthetic analogues? How is the bioavailability of the compounds of interest in relation to the above source? Is there any biological activity by circulating metabolic derivatives? What is the best formulation, administration route and posology? How safe are in humans? How strong and reliable are the clinical trials designed for their use alone or in combination with conventional chemotherapy? After a dissertation of these critical points, the conclusion can be drawn that novel and effective strategies should be optimized to improve their bioavailability and efficacy, considering their exploitation as chemopreventive and/or curative approaches. [ABSTRACT FROM AUTHOR]

Purpose: To survey the changes of promoter CpG methylation status and mRNA expression of IL17RC (interleukin 17 receptor C) gene in retinal pigment epithelium (RPE) cells under chemical hypoxia condition for choroidal neovascularization (CNV) modelingin vitro. Materials and Methods: RPE cells were cultured in both untreated as a control group and treated by cobalt chloride media as a hypoxia group for various concentrations (100–150μM) and times (24–36 hrs.) To confirm chemical hypoxia condition, mRNA expression of HIF (Hypoxia Inducible Factor) -1α, -2α, and Vascular Endothelial Growth Factor (VEGF) was compared between two groups by Real-time PCR. Also, in normoxia and hypoxia conditions, IL17RC expression changes and promoter CpG methylation status were evaluated by Real-time PCR and methylation-specific PCR (MSP) techniques, respectively. Results: Overexpression of HIF-1α, HIF-2α, and VEGF was significant in hypoxia versus normoxia conditions. Our data showed overexpression of IL17RC (2.1- to 6.3-fold) and decreasing of its promoter methylation in comparison with hypoxia and normoxia conditions. It was found that there are significant association between promoter methylation status and expression of IL17RC in chemical hypoxia condition. Conclusion: Therefore, methylation of IL17RC could play as a marker in CNV and degeneration of RPE cellsin vitro. Additionally, HIF-α and methylation phenomena may be considered as critical targets for blocking in angiogenesis of age-related degeneration in future studies. [ABSTRACT FROM AUTHOR]

This review intended to provide an overview of the effects of dental materials, used in dentin-pulp complex and dental pulp regeneration, on angiogenesis processes during regenerative endodontic procedures. An electronic search was performed in PubMed and MEDLINE databases via OVID using the keywords mentioned in the PubMed and MeSH headings for English language published articles from January 2005-April 2014 that evaluated the angiogenic properties of different dental materials used in regenerative endodontic procedures. Of the articles identified in an initial search, only 40 articles met the inclusion criteria set for this review. Vital pulp therapy materials might have positive effects on angiogenesis events, while most of the canal irrigating solutions and antibiotic pastes have anti-angiogenic activity except for EDTA. Future clinical studies will be helpful in defining the mechanisms of action for dental materials that promote or inhibit angiogenesis events at applied areas. [ABSTRACT FROM AUTHOR]

The role of hemodynamic forces within the embryo as biomechanical regulators for cardiovascular morphogenesis, growth, and remodeling is well supported through the experimental studies. Furthermore, clinical experience suggests that perturbed flow disrupts the normal vascular growth process as one etiology for congenital heart diseases (CHD) and for fetal adaptation to CHD. However, the relationships between hemodynamics, gene expression and embryonic vascular growth are poorly defined due to the lack of concurrent, sequential in vivo data. In this study, a long-term, time-lapse optical coherence tomography (OCT) imaging campaign was conducted to acquire simultaneous blood velocity, pulsatile micro-pressure and morphometric data for 3 consecutive early embryonic stages in the chick embryo. In conjunction with the in vivo growth and hemodynamics data, in vitro reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to track changes in transcript expression relevant to histogenesis and remodeling of the embryonic arterial wall. Our non-invasive extended OCT imaging technique for the microstructural data showed continuous vessel growth. OCT data coupled with the PIV technique revealed significant but intermitted increases in wall shear stress (WSS) between first and second assigned stages and a noticeable decrease afterwards. Growth rate, however, did not vary significantly throughout the embryonic period. Among all the genes studied, only the MMP-2 and CASP-3 expression levels remained unchanged during the time course. Concurrent relationships were obtained among the transcriptional modulation of the genes, vascular growth and hemodynamics-related changes. Further studies are indicated to determine cause and effect relationships and reversibility between mechanical and molecular regulation of vasculogenesis. [ABSTRACT FROM AUTHOR]

The polarity and organization of radial glial cells (RGCs), which serve as both stem cells and scaffolds for neuronal migration, are crucial for cortical development. However, the cytoskeletal mechanisms that drive radial glial outgrowth and maintain RGC polarity remain poorly understood. Here, we show that the Arp2/3 complex -- the unique actin nucleator that produces branched actin networks -- plays essential roles in RGC polarity and morphogenesis. Disruption of the Arp2/3 complex in murine RGCs retards process outgrowth toward the basal surface and impairs apical polarity and adherens junctions. Whereas the former is correlated with an abnormal actin-based leading edge, the latter is consistent with blockage in membrane trafficking. These defects result in altered cell fate, disrupted cortical lamination and abnormal angiogenesis. In addition, we present evidence that the Arp2/3 complex is a cell-autonomous regulator of neuronal migration. Our data suggest that Arp2/3-mediated actin assembly might be particularly important for neuronal cell motility in a soft or poorly adhesive matrix environment. [ABSTRACT FROM AUTHOR]

Purpose To determine the prevalence of high myopia (HM), progressive high (degenerative) myopia (PHM), and myopic choroidal neovascularization (mCNV) in the United States. Design Cross-sectional study. Participants Individuals aged 18 years and older participating in the National Health and Nutrition Examination Survey (NHANES) and patients aged 18 years and older seen in clinics participating in the American Academy of Ophthalmology's Intelligent Research in Sight (IRIS ® ) Registry. Methods We analyzed NHANES data from 2005 to 2008 to determine the prevalence of HM in the United States. This prevalence was then applied to estimates from the US Population Census (2014) to arrive at a population burden of HM at the diopter level in the United States. Data from the IRIS Registry were used to calculate the real-world prevalence rates of PHM and mCNV among patients with HM at the diopter level. This was subsequently applied to this reference population with HM to calculate the diopter-adjusted prevalence and population burden of PHM and mCNV in the United States in 2014. Main Outcome Measures High myopia was defined as myopic refractive error of ≤6.0 diopters in the right eye. Progressive HM was defined as HM with the International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) code of “360.21: Progressive High (Degenerative) Myopia.” Myopic CNV was defined as HM with the presence of subretinal/choroidal neovascularization indicated by the ICD-9-CM diagnosis of “362.16: Retinal Neovascularization NOS.” Results The estimated diopter-adjusted prevalence of HM, PHM, and mCNV was 3.92% (95% confidence interval [CI], 2.82–5.60), 0.33% (95% CI, 0.21–0.55), and 0.017% (95% CI, 0.010–0.030), respectively, among adults in the United States aged 18 years and older in 2014. This translated into a population burden of approximately 9 614 719 adults with HM, 817 829 adults with PHM, and 41 111 adults with mCNV in the United States in 2014. Conclusions Although HM and PHM impose a relatively large burden among adults in the United States, mCNV seems to be a rare disease. Relating data from the IRIS Registry and NHANES could be a novel method for assessing ophthalmic disease prevalence in the United States. Future studies should aim to better assess current treatment patterns and optimal management strategies of this condition. [ABSTRACT FROM AUTHOR]

Veins are longitudinal cuticular structures that maintain shape of the wing. Drosophila melanogaster has six longitudinal veins (L1–L6) and two cross veins. The Zn-finger transcription factors of Spalt-complex (Sal) are required for positioning of the L2 and L5, and the homeodomain transcription factors of Iroquois complex (Iro-C) are required for formation of the L3 and L5 veins. The homeodomain transcriptional repressor Defective proventriculus (Dve) is uniformly expressed in the wing pouch of the larval imaginal disc. However, dve mutant wings showed loss of the L2 and L5, but not of the L3 and L4 veins. Temporal dve knockdown experiments indicate that the Dve activity is required for vein formation from late third larval instar to the prepupal stage. In the prepupal wing, Dve expression becomes nearly complementary to that of Sal through the Sal-mediated dve repression. Furthermore, coexpression of Dve and Iro-C relieved of Sal-mediated repression is required for the L5 formation in a dose-dependent manner. The relationship between Sal, Dve, and Iro-C in wing vein specification is quite similar to that in ommatidial cell-type specification. Our results provide information about the conserved function of dve regulatory motifs in cell differentiation. [ABSTRACT FROM AUTHOR]

Background: Type IV collagen is the main component of the basement membrane that gives strength to the blood-gas barrier (BGB). In mammals, the formation of a mature BGB occurs primarily after birth during alveologenesis and requires the formation of septa from the walls of the saccule. In contrast, in avians, the formation of the BGB occurs rapidly and prior to hatching. Mutation in basement membrane components results in an abnormal alveolar phenotype; however, the specific role of type IV collagen in regulating alveologenesis remains unknown. Results: We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian BGB. Using mouse models, we discovered that mutations in murine Col4a1 and Col4a2 genes affected the balance between lung epithelial progenitors and differentiated cells. Mutations in Col4a1 derived from the vascular component were sufficient to cause defects in vascular development and the BGB. We also show that Col4a1 and Col4a2 mutants displayed disrupted myofibroblast proliferation, differentiation and migration. Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer culture and increased the formation of mesenchymal-epithelial septal-like structures in co-culture. Conclusions: Our study showed that type IV collagen and, therefore the basement membrane, play fundamental roles in coordinating alveolar morphogenesis. In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar myofibroblast development by inducing their proliferation, differentiation and migration throughout the developing septum. [ABSTRACT FROM AUTHOR]

Angiogenesis, the formation of new blood vessels from preexisting ones, is critical to luteal structure and function. In addition, it is a complex and tightly regulated process. Not only does rapid and extensive angiogenesis occur to provide the corpus luteum with an unusually high blood flow and support its high metabolic rate, but in the absence of pregnancy, the luteal vasculature must rapidly regress to enable the next cycle of ovarian activity. This review describes a number of key endogenous stimulatory and inhibitory factors, which act in a delicate balance to regulate luteal angiogenesis and ultimately luteal function. In vitro luteal angiogenesis cultures have demonstrated critical roles for fibroblast growth factor 2 (FGF2) in endothelial cell proliferation and sprouting, although other factors such as vascular endothelial growth factor A (VEGFA) and platelet-derived growth factor were important modulators in the control of luteal angiogenesis. Post-transcriptional regulation by small non-coding microRNAs is also likely to play a central role in the regulation of luteal angiogenesis. Appropriate luteal angiogenesis requires the coordinated activity of numerous factors expressed by several cell types at different times, and this review will also describe the role of perivascular pericytes and the importance of vascular maturation and stability. It is hoped that a better understanding of the critical processes underlying the transition from follicle to corpus luteum and subsequent luteal development will benefit the management of luteal function in the future. [ABSTRACT FROM AUTHOR]

A major hindrance in islet transplantation as a feasible therapeutic approach for patients with type 1 diabetes is the insufficient oxygenation of the grafts, which results in cell death in portions of the implant. Here we address this limitation through the application of oxygen-generating microparticles (MP) and a fibrin-conjugated heparin/VEGF collagen scaffold to support cell survival by using a β cell line and pancreatic rat islets. MP are composed of a polyvinylpyrrolidone/hydrogen peroxide (PVP/H 2 O 2 ) core and poly( d , l -lactide-co-glycolide) (PLGA) shell, along with immobilized catalase on the shell. The presence of MP is sufficient to reduce hypoxia-induced cell dysfunction and death for both cell types, resulting in localization of hypoxia-inducible factor (HIF-1α) into the cytoplasm and enhanced metabolic function. After co-transplantation of MP and a reduced islet mass (250 islet equivalents) within an angiogenic scaffold in the omental pouch of streptozotocin-induced diabetic nude mice, we have observed significantly promoted graft function as evidenced by improved blood glucose levels, body weight, glucose tolerance, serum C-peptide, and graft revascularization. These results suggest that the developed platform has great potential to enhance the efficacy for implants in cases where the cell dosage is critical for efficacy, such as islet transplantation and ischemic tissues. [ABSTRACT FROM AUTHOR]

Purpose: Fibrovascular scar formation related to subfoveal type 2 choroidal neovascularization (CNV) often causes severe vision loss in eyes with age-related macular degeneration. The authors assessed additional impacts of intravitreal tissue plasminogen activator (tPA), a fibrinolytic compound, combined with intravitreal ranibizumab (IVR) on subfoveal type 2 CNV. Methods: Eight eyes of eight patients with type 2 CNV underwent intravitreal injections of ranibizumab and tPA (IVR/tPA) (40 kIU). Twelve eyes of 12 patients with type 2 CNV were treated with only IVR injections, as the control group. For retreatment, IVR was performed as needed. The best-corrected visual acuity (BCVA) and the central retinal thickness (CRT) and macular volume (MV) on optical coherence tomography were recorded periodically for 6 months. Results: The subretinal fibrinous and fibrovascular tissue complex regressed or contracted immediately after administration of IVR/tPA in contrast to IVR monotherapy. The total numbers of IVR injections did not differ significantly between the two groups. The mean logarithm of the minimum angle of resolution BCVA in the combination therapy group improved significantly from 0.72 at baseline to 0.51 at month 6 and was superior to that in the monotherapy group (0.70-0.79). The improvements of the mean CRT and MV in the combination therapy group were superior to the monotherapy group. No tPA-related complications developed. Conclusions: tPA may have a specific ability to regress already formed subretinal fibrinous and fibrovascular tissue complexes in eyes with type 2 CNV, potentially increasing the chances of visual improvement through a synergistic relationship with anti-VEGF therapies. [ABSTRACT FROM AUTHOR]

As a form of therapeutic angiogenesis, we sought to investigate the safety and efficacy of a sustained-release system of basic fibroblast growth factor (bFGF) using biodegradable gelatin hydrogel in patients with critical limb ischemia (CLI). We conducted a phase I-IIa study that analyzed 10 CLI patients following a 200-μg intramuscular injection of bFGF-incorporated gelatin hydrogel microspheres into the ischemic limb. Primary endpoints were safety and transcutaneous oxygen pressure (TcO) at 4 and 24 weeks after treatment. During the follow-up, there was no death or serious procedure-related adverse event. After 24 weeks, TcO (28.4 ± 8.4 vs. 46.2 ± 13.0 mmHg for pretreatment vs after 24 weeks, p < 0.01) showed significant improvement. Regarding secondary endpoints, the distance walked in 6 min (255 ± 105 vs. 318 ± 127 m, p = 0.02), the Rutherford classification (4.4 ± 0.5 vs. 3.1 ± 1.4, p = 0.02), the rest pain scale (1.7 ± 1.0 vs. 1.2 ± 1.3, p = 0.03), and the cyanotic scale (2.0 ± 1.1 vs. 0.9 ± 0.9, p < 0.01) also showed improvement. The blood levels of bFGF were within the normal range in all patients. A subanalysis of patients with arteriosclerosis obliterans ( n = 7) or thromboangiitis obliterans (Buerger's disease) ( n = 3) revealed that TcO had significantly improved in both subgroups. TcO did not differ between patients with or without chronic kidney disease. The sustained release of bFGF from biodegradable gelatin hydrogel may offer a safe and effective form of angiogenesis for patients with CLI. [ABSTRACT FROM AUTHOR]

Formation of new blood vessels in tumors, a process termed tumor angiogenesis, is a crucial step during oncogenic progression. Blocking tumor angiogenesis is therefore expected to have a profound impact on tumor growth. It took several decades of collective efforts to translate this intriguing idea into tangible clinical benefit. Today, anti-angiogenesis agents represent standard-of-care therapies for multiple types of cancers, and the clinical experience has taught us many lessons about the concept and application of anti-angiogenesis. This Perspective is an attempt to summarize these lessons and how they can be leveraged to improve anti-angiogenesis therapy. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to determine risk factors associated with delayed regression of retinopathy of prematurity and prolonged vascular completion in patients not requiring treatment. Material and Methods: Patients with acute retinopathy of prematurity not requiring treatment were grouped as control and delayed vascularization groups, on condition that retinal vascularization had completed before postconceptional age of 50 weeks or not. Patients with retinopathy of prematurity requiring treatment constituted treatment group. A total of 17 possible risk factors that may affect the time course of retinal vascularization in patients with acute retinopathy of prematurity were evaluated. Results: Multivariate regression analysis showed that low Apgar score at fifth minute and blood transfusion were associated with an increased risk of delayed vascularization when compared with controls. Low gestational age and presence of patent ductus arteriosus were risk factors for retinopathy of prematurity that require treatment when compared with delayed vascularization group. Conclusion: Low Apgar score and blood transfusion might be predictive factors for prolonged retinal vascularization in patients with retinopathy of prematurity not requiring treatment. Having a higher gestational age and absence of patent ductus arteriosus, appeared as reducing the risk of progressing to serious disease requiring treatment for an infant with retinopathy of prematurity that undergo regression slowly. [ABSTRACT FROM AUTHOR]

Cardiovascular function depends on patent, continuous and stable blood vessel formation by endothelial cells (ECs). Blood vessel development initiates by vasculogenesis, as ECs coalesce into linear aggregates and organize to form central lumens that allow blood flow. Molecular mechanisms underlying in vivo vascular 'tubulogenesis' are only beginning to be unraveled. We previously showed that the GTPase-interacting protein called Rasip1 is required for the formation of continuous vascular lumens in the early embryo. Rasip1 ECs exhibit loss of proper cell polarity and cell shape, disrupted localization of EC-EC junctions and defects in adhesion of ECs to extracellular matrix. In vitro studies showed that Rasip1 depletion in cultured ECs blocked tubulogenesis. Whether Rasip1 is required in blood vessels after their initial formation remained unclear. Here, we show that Rasip1 is essential for vessel formation and maintenance in the embryo, but not in quiescent adult vessels. Rasip1 is also required for angiogenesis in three models of blood vessel growth: in vitro matrix invasion, retinal blood vessel growth and directed in vivo angiogenesis assays. Rasip1 is thus necessary in growing embryonic blood vessels, postnatal angiogenic sprouting and remodeling, but is dispensable for maintenance of established blood vessels, making it a potential anti-angiogenic therapeutic target. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The mechanisms underlying organ vascularization are not well understood. The zebrafish intestinal vasculature forms early, is easily imaged using transgenic lines and in-situ hybridization, and develops in a stereotypical pattern thus making it an excellent model for investigating mechanisms of organ specific vascularization. Here, we demonstrate that the sub-intestinal vein (SIV) and supra-intestinal artery (SIA) form by a novel mechanism from angioblasts that migrate out of the posterior cardinal vein and coalesce to form the intestinal vasculature in an anterior to posterior wave with the SIA forming after the SIV. We show that vascular endothelial growth factor aa (vegfaa) is expressed in the endoderm at the site where intestinal vessels form and therefore likely provides a guidance signal. Vegfa/Vegfr2 signaling is required for early intestinal vasculature development with mutation in vegfaa or loss of Vegfr2 homologs causing nearly complete inhibition of the formation of the intestinal vasculature. Vegfc and Vegfr3 function, however, are dispensable for intestinal vascularization. Interestingly, ubiquitous overexpression of Vegfc resulted in an overgrowth of the SIV, suggesting that Vegfc is sufficient to induce SIV development. These results argue that Vegfa signaling directs endothelial cells to migrate out of existing vasculature and coalesce to form the intestinal vessels. It is likely that a similar mechanism is utilized during vascularization of other organs. [ABSTRACT FROM AUTHOR]