Effects of vascular endothelial growth factor on hemodynamics and cardiac performance

Influence of genetic polymorphisms in vascular endothelial-related genes on the clinical outcome of axitinib in patients with metastatic renal cell carcinoma

OBJECTIVE

Axitinib is an oral multi-target tyrosine kinase inhibitor used for the treatment of renal cell carcinoma (RCC). Because of the severe adverse events (AEs) associated with axitinib, patients often need dose reductions or discontinue its use, highlighting the need for effective biomarkers to assess efficacy and/or AEs. The aim of this study was to investigate the relationship between single nucleotide polymorphisms (SNPs) in genes involved in the pharmacodynamic action of axitinib and clinical prognosis and AEs in metastatic RCC (mRCC) patients.

METHODS

This study included 80 mRCC patients treated with first-, second-, or third-line axitinib (5 mg orally twice daily). Clinical parameters and genetic polymorphisms were examined in 75 cases (53 males and 22 females). We assessed three SNPs in each of three candidate genes namely, angiotensin-converting enzyme (ACE), nitric oxide synthase 3 (NOS3), and angiotensin II receptor type 1 (AT1R), all of which are involved in axitinib effects on vascular endothelial function.

RESULTS

Axitinib-treated patients carrying the ACE deletion allele suffered more frequently from hand-foot syndrome and a deterioration in kidney function (p  = .045 and p =  0.005, respectively) whereas those carrying the NOS3 G allele suffered more frequently from proteinuria and multiple AEs (p  = .025 and p =  0.036, respectively).

CONCLUSIONS

Our study found that the ACE deletion allele and the NOS3 G allele are associated with increased AEs.

Macrophage IL-1β promotes arteriogenesis by autocrine STAT3- and NF-κB-mediated transcription of pro-angiogenic VEGF-A

Peripheral artery disease (PAD) leads to considerable morbidity, yet strategies for therapeutic angiogenesis fall short of being impactful. Inflammatory macrophage subsets play an important role in orchestrating post-developmental angiogenesis, but the underlying mechanisms are unclear. Here, we find that macrophage VEGF-A expression is dependent upon the potent inflammatory cytokine, IL-1β. IL-1β promotes pro-angiogenic VEGF-A₁₆₅a isoform transcription via activation and promoter binding of STAT3 and NF-κB, as demonstrated by gene-deletion, gain-of-function, inhibition, and chromatin immunoprecipitation assays. Conversely, IL-1β-deletion or inhibition of STAT3 or NF-κB increases anti-angiogenic VEGF-A₁₆₅b isoform expression, indicating IL-1β signaling may also direct splice variant selection. In an experimental PAD model of acute limb ischemia, macrophage IL-1β expression is required for pro-angiogenic VEGF-A expression and for VEGF-A-induced blood flow recovery via angio- or arteriogenesis. Though further study is needed, macrophage IL-1β-dependent transcription of VEGF-A via STAT3 and NF-κB may have potential to therapeutically promote angiogenesis in the setting of PAD.

Mantsounga et al. show inflammatory macrophage IL-1β expression to be required for pro-angiogenic VEGF-A expression and consequent post-developmental angio- or arteriogenesis in an experimental model of peripheral artery disease. Autocrine IL-1β signaling promotes transcription of pro-angiogenic VEGF-A₁₆₅a isoform expression relative to anti-angiogenic isoform, VEGF-A₁₆₅b, through activation of STAT3 and NF-κB.

VEGFR2 in vascular smooth muscle cells mediates H2S-induced dilation of the rat cerebral basilar artery

INTRODUCTION

The aim of present study was to study whether the vascular endothelial growth factor receptor 2 (VEGFR₂) mediates hydrogen sulfide (H₂S)-induced relaxation of the rat cerebral vasculature.

METHODS

Relaxation of cerebral basilar artery (CBA) and vascular smooth muscle cells (VSMCs) was measured by using a pressure myograph system and image analysis system, respectively. The intracellular calcium concentration ([Ca²⁺]_i) in VSMCs was detected using fluorescence imaging analysis.

RESULTS

We found that H₂S donor NaHS induced significant relaxation of VSMCs from the CBA of wild type rat, but in VEGFR₂ knockdown VSMCs, NaHS-induced relaxation reduced markedly. In addition, NaHS-induced vasodilation of rat CBA also attenuated obviously when the expression of VEGFR₂ was knocked down in vivo. In addition, pretreatment with the VEGFR₂ blocker SU5416 likewise lowered the NaHS-induced relaxation of rat CBA. Nevertheless, the VEGFR₂ agonist, vascular endothelial growth factor 164 (VEGF164), induced a concentration-dependent relaxation of CBA, which is similar to the effect of NaHS. Furthermore, we found that both NaHS and VEGF164 significantly inhibited the U₄₆₆₁₉-induced increase of [Ca²⁺]_i fluorescence intensity in the VSMCs. However, the inhibitory effect of NaHS on the [Ca²⁺]_i fluorescence intensity in VSMCs was markedly inhibited by pretreatment with SU5416 or VEGFR₂ knockdown.

CONCLUSION

These findings indicated that H₂S-induced CBA dilation and reduction of [Ca²⁺]_i in VSMCs occur by acting on VEGFR₂.

Snake venom vascular endothelial growth factors (svVEGFs): Unravelling their molecular structure, functions, and research potential

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis, a physiological process characterized by the formation of new vessels from a preexisting endothelium. VEGF has also been implicated in pathologic states, such as neoplasias, intraocular neovascular disorders, among other conditions. VEGFs are distributed in seven different families: VEGF-A, B, C, D, and PIGF (placental growth factor), which are identified in mammals; VEGF-E, which are encountered in viruses; and VEGF-F or svVEGF (snake venom VEGF) described in snake venoms. This is the pioneer review of svVEGF family, exploring its distribution among the snake venoms, molecular structure, main functions, and potential applications.

Hypertension and Prohypertensive Antineoplastic Therapies in Cancer Patients

The development of a wide range of novel antineoplastic therapies has improved the prognosis for patients with a wide range of malignancies, which has increased the number of cancer survivors substantially. Despite the oncological benefit, cancer survivors are exposed to short- and long-term adverse cardiovascular toxicities associated with anticancer therapies. Systemic hypertension, the most common comorbidity among cancer patients, is a major contributor to the increased risk for developing these adverse cardiovascular events. Cancer and hypertension have common risk factors, have overlapping pathophysiological mechanisms and hypertension may also be a risk factor for some tumor types. Many cancer therapies have prohypertensive effects. Although some of the mechanisms by which these antineoplastic agents lead to hypertension have been characterized, further preclinical and clinical studies are required to investigate the exact pathophysiology and the optimal management of hypertension associated with anticancer therapy. In this way, monitoring and management of hypertension before, during, and after cancer treatment can be improved to minimize cardiovascular risks. This is vital to optimize cardiovascular health in patients with cancer and survivors, and to ensure that advances in terms of cancer survivorship do not come at the expense of increased cardiovascular toxicities.

PI3K/AKT signaling drives titanium-induced angiogenic stimulus

Although osseointegration and clinical success of titanium (Ti)-implanted materials depend on neovascularization in the reactional peri-implant tissue, very little has been achieved considering the Ti-molecules release on the behavior of endothelial cells. To address this issue, we challenged endothelial cells (HUVECs) with Ti-enriched medium obtained from two types of commercial titanium surfaces [presenting or not dual-acid etching (DAE)] up to 72 h to allow molecular machinery analysis. Our data show that the Ti-enriched medium provokes significant stimulus of angiogenesis-related machinery in endothelial cells by upexpressing VEGFR1, VEGFR2, VEGF, eNOS, and iNOS genes, while the PI3K/Akt signaling pathway was also significantly enhanced. As PI3K/AKT signaling was related to angiogenesis in response to vascular endothelial growth factor (VEGF), we addressed the importance of PI3K/Akt upon Ti-enriched medium responses by concomitantly treating the cells with wortmannin, a well-known PI3K inhibitor. Wortmannin suppressed the angiogenic factors, because VEGF, VEGFR1, and eNOS genes were downregulated in those cells, highlighting the importance of PI3K/AKT signaling on driving angiogenic phenotype and angiogenesis performance within the peri-implant tissue reaction. In conjunction, these data reinforce that titanium-implantable devices modify the metabolism of surrounding cells, such as endothelial cells, probably coupling osteogenesis and angiogenesis processes in peri-implant tissue and then contributing to successfully osseointegration of biomedical titanium-based devices.

Collagen/heparin scaffold combined with vascular endothelial growth factor promotes the repair of neurological function in rats with traumatic brain injury

The objective of this study was to evaluate the therapy effects of a novel biological scaffold containing heparin, collagen and vascular endothelial growth factor (VEGF) in treating traumatic brain injury (TBI).

Hypotheses about sub-optimal hydration in the weeks before coronavirus disease (COVID-19) as a risk factor for dying from COVID-19

To address urgent need for strategies to limit mortality from coronavirus disease 2019 (COVID-19), this review describes experimental, clinical and epidemiological evidence that suggests that chronic sub-optimal hydration in the weeks before infection might increase risk of COVID-19 mortality in multiple ways. Sub-optimal hydration is associated with key risk factors for COVID-19 mortality, including older age, male sex, race-ethnicity and chronic disease. Chronic hypertonicity, total body water deficit and/or hypovolemia cause multiple intracellular and/or physiologic adaptations that preferentially retain body water and favor positive total body water balance when challenged by infection. Via effects on serum/glucocorticoid-regulated kinase 1 (SGK1) signaling, aldosterone, tumor necrosis factor-alpha (TNF-alpha), vascular endothelial growth factor (VEGF), aquaporin 5 (AQP5) and/or Na⁺/K⁺-ATPase, chronic sub-optimal hydration in the weeks before exposure to COVID-19 may conceivably result in: greater abundance of angiotensin converting enzyme 2 (ACE2) receptors in the lung, which increases likelihood of COVID-19 infection, lung epithelial cells which are pre-set for exaggerated immune response, increased capacity for capillary leakage of fluid into the airway space, and/or reduced capacity for both passive and active transport of fluid out of the airways. The hypothesized hydration effects suggest hypotheses regarding strategies for COVID-19 risk reduction, such as public health recommendations to increase intake of drinking water, hydration screening alongside COVID-19 testing, and treatment tailored to the pre-infection hydration condition. Hydration may link risk factors and pathways in a unified mechanism for COVID-19 mortality. Attention to hydration holds potential to reduce COVID-19 mortality and disparities via at least 5 pathways simultaneously.

Hyperviscosity-related splenic infarction, gastrointestinal ischaemia-reperfusion injury and transient dysarthria in a patient with distributive shock due to idiopathic systemic capillary leak syndrome (Clarkson's syndrome)

Clarkson's syndrome, also known as idiopathic systemic capillary leak syndrome, is characterised by vascular hyperpermeability resulting in intravascular hypovolaemia and shock. A clinician should consider the diagnosis if other causes of shock, for example, sepsis and anaphylaxis, are ruled out and concomitant hyperviscosity is not caused by a myeloproliferative disease. Here, we describe a patient presenting with severe plasma leakage and assumable blood hyperviscosity leading to splenic infarction, gastrointestinal ischaemia-reperfusion syndrome and transient dysarthria. Our patient was first suspected of polycythaemia vera and phlebotomies were performed. Awareness of this syndrome and subsequent correct treatment is essential to prevent complications and to reduce mortality. As in our patient, most patients with Clarkson's syndrome have a monoclonal gammopathy, light-chain-type kappa. Prophylactic treatment with intravenous immunoglobulin (IVIg) is advised to prevent recurrence of capillary leak. Our patient did not suffer from another symptomatic episode after starting IVIg.

Is there truly an increase in risk of cardiovascular and hematological adverse events with vascular endothelial growth factor receptor tyrosine kinase inhibitors?

Objectives: Recent studies have shown an increase risk of cardiovascular and hematological adverse events associated with vascular endothelial growth factor tyrosine kinase inhibitors (VEGF-TKIs). The authors hypothesize that the original studies may have produced exaggerated results because of the small baseline risks involved.Methods: A meta-analysis that included 71 trials, 8 different VEGFR-TKIs, and 11 adverse events were re-analyzed. The outcome of interest was re-defined as the complementary outcome (i.e. remaining free of an adverse event). The inverse variance heterogeneity model was used to pool the effect size.Results: VEGFR-TKIs decreased the risk of remaining free of hypertension by 7% (RR 0.93; 95%CI:0.88-0.97). Specific VEGFR-TKIs; pazopanib, regorafenib, and nintedanib were associated with a decrease risk of remaining free of an arterial thrombotic event (RR 0.96; 95%CI:0.93-0.99), thrombocytopenia (RR 0.91; 95%CI:0.89-0.93), and bleeding (RR 0.96; 95%CI:0.93-0.99) respectively. VEGFR-TKIs were not associated with the thrombotic event, myocardial infarction, stroke, venous thrombotic event, pulmonary embolism, left ventricular dysfunction, or QTc interval prolongation.Conclusion: VEGFR-TKIs are associated with a small increase in the risk of patients developing hypertension, arterial thrombotic events, thrombocytopenia, and bleeding. Previous studies overestimated the actual risk associated with VEGFR-TKIs by analyzing the outcome with the lower baseline risk.

Effect of Panax ginseng extract on the activity of diabetic fibroblasts in vitro

Numerous studies have demonstrated the various medicinal properties of Panax ginseng, including angiogenic, immuno-stimulating, antimicrobial, and anti-inflammatory activities, which can be helpful in chronic wound healing. However, a direct role for P. ginseng in chronic wound healing has not been demonstrated. The present study was designed to evaluate the effects of P. ginseng extract on diabetic fibroblasts in vitro. Human diabetic fibroblasts were cultured in the presence of Ginsenoside Rb1 (G-Rb1), the active component in P. ginseng (10 ng/mL), and untreated diabetic fibroblasts were used as controls. Cell proliferation, collagen synthesis, the production of various growth factors (basic fibroblast growth factor [bFGF]; vascular endothelial growth factor [VEGF]; and transforming growth factor-β1 [TGF-β1]), and the synthesis of matrix metalloproteinase 1 (MMP-1) and tissue inhibitor of metalloproteinases 1 (TIMP-1) were compared using enzyme-linked immunosorbent assay and immunofluorescence staining. Compared with the control group, G-Rb1-treated fibroblasts showed significantly (P < 0.05) higher levels of cell proliferation, collagen synthesis, VEGF, TGF-β1, and TIMP-1. However, no significant differences in bFGF and MMP-1 levels were observed between the two groups. These results suggest that P. ginseng treatment may stimulate the wound-healing activity of diabetic fibroblasts in vitro.

A novel granulin homologue isolated from the jellyfish Cyanea capillata promotes proliferation and migration of human umbilical vein endothelial cells through the ERK1/2-signaling pathway

Jellyfish grow rapidly and have a strong regenerative ability, indicating that they may express high levels of growth factors. Therefore, the aim of this research was to isolate the growth-promoting components from the jellyfish Cyanea capillata (C. capillata) and to further explore the underlying mechanisms. In this study, we first isolated and identified a novel polypeptide from C. capillata tentacles using size-exclusion chromatography followed by reverse-phase HPLC. This peptide, consisting of 58 amino acids (MW 5782.9 Da), belonged to the granulin (GRN) family of growth factors; thus, we named it Cyanea capillata granulin-1 (CcGRN-1). Second, using CCK-8 assay and flow cytometry, we verified that CcGRN-1 at the 0.5 μg/ml concentration could promote cell proliferation and increase the expression of cell-cycle proteins (CyclinB1 and CyclinD1). Third, signaling pathways studies showed that CcGRN-1 could activate the PI3K/Akt- and ERK1/2 MAPK-signaling pathways but not the JNK MAPK- or NF-κB-signaling pathways. Subsequently, we further confirmed that the CcGRN-1-induced cell proliferation and migration were associated only with the ERK1/2 MAPK-signaling pathway. Considering all of these factors, CcGRN-1, as the first jellyfish-derived GRN homologue, possesses growth-promoting properties and may be a candidate for novel therapeutics to promote human wound healing in unfavorable conditions.

Acute iodine deficiency induces a transient VEGF-dependent microvascular response in mammary glands involving HIF-1, ROS, and mTOR

Iodine deficiency (ID), which affects almost two billion people worldwide, is associated with breast pathologies such as fibrosis in human and induces breast atypia in animal models. Because ID induces vascular activation in the thyroid, another iodide-uptaking organ, and as breast is also sensitive to ID, we aimed to characterize ID-induced effects on the breast microvasculature in vivo and in two different breast cell lines in vitro. Virgin and lactating NMRI mice received an iodide-deficient diet and a Na⁺/I^- symporter inhibitor for 1 to 20 days. Some virgin mice were treated with vascular endothelial growth factor A (VEGF) or VEGF receptor inhibitors. In vitro, ID was induced in MCF7 and MCF12A cells by replacing the iodide-containing medium by an iodide-deficient medium. In vivo, VEGF expression was increased following ID in mammary tissues. Consequently, ID induced a transient increase in mammary gland blood flow, measured after anesthesia, in virgin and lactating mice, which was repressed by VEGF or VEGF receptor inhibitors. In MCF7 cells, ID induced a transient increase in reactive oxygen species, followed by an increase in hypoxia-inducible factor-1α (HIF-1α) protein and VEGF mRNA expression. Antioxidant N-acetylcysteine and mammalian target of rapamycin (mTOR) inhibitor blocked ID-induced HIF-1α protein increase and VEGF transcription. However, mTOR activity was not inhibited by N-acetylcysteine. Similar responses were observed in MCF12A cells. These data indicate that ID activates the canonical VEGF pathway and mTOR in breast tissues, which provides new insights to better understand the correlation between ID, vascular activation, and breast pathologies.

Regulation of vascular permeability in anaphylaxis

Anaphylaxis is a life-threatening type I allergic reaction. Antigen-antibody complexes induce mast cells, basophils and neutrophils to release large amounts of histamine and/or PAF. These mediators induce hypotension and vascular hyper-permeability and subsequent anaphylaxis dependent on the endothelial production of NO. Here, we have summarized previous studies reporting the mechanisms underlying the functional changes within the vasculature, specifically focusing on vascular permeability triggered by histamine or PAF. In addition to these pro-inflammatory factors, PGD2 is abundantly released in anaphylaxis, mainly from mast cells. We recently demonstrated that mast cell-derived PGD2 attenuates anaphylactic responses by inhibiting vascular hyper-permeability in mouse models. Our findings suggest that pro- and anti-inflammatory factors concurrently regulate vascular permeability in anaphylaxis. In this mini-review, we discuss the multifactorial mechanisms underlying vascular hyper-permeability in anaphylaxis.

Intranasal delivery of VEGF enhances compensatory lung growth in mice

Vascular endothelial growth factor (VEGF) has previously been demonstrated to accelerate compensatory lung growth (CLG) in mice and may be a useful therapy for pulmonary hypoplasia. Systemic administration of VEGF can result in side effects such as hypotension and edema. The aim of this study was to explore nasal delivery as a route for intrapulmonary VEGF administration. Eight-week-old C57BL/6 male mice underwent left pneumonectomy, followed by daily nasal instillation of VEGF at 0.5 mg/kg or isovolumetric saline. Lung volume measurement, morphometric analysis, and protein expression studies were performed on lung tissues harvested on postoperative day (POD) 4. To understand the mechanism by which VEGF accelerates lung growth, proliferation of human bronchial epithelial cells (HBEC) was assessed in a co-culture model with lung microvascular endothelial cells (HMVEC-L) treated with and without VEGF (10 ng/mL). The assay was then repeated with a heparin-binding EGF-like growth factor (HB-EGF) neutralizing antibody ranging from 0.5-50 μg/mL. Compared to control mice, the VEGF-treated group displayed significantly higher lung volume (P = 0.001) and alveolar count (P = 0.005) on POD 4. VEGF treatment resulted in increased pulmonary expression of HB-EGF (P = 0.02). VEGF-treated HMVEC-L increased HBEC proliferation (P = 0.002) while the addition of an HB-EGF neutralizing antibody at 5 and 50 μg/mL abolished this effect (P = 0.01 and 0.002, respectively). These findings demonstrate that nasal delivery of VEGF enhanced CLG. These effects could be mediated by a paracrine mechanism through upregulation of HB-EGF, an epithelial cell mitogen.

Treatment-emergent hypertension and efficacy in the phase 3 Study of (E7080) lenvatinib in differentiated cancer of the thyroid (SELECT)

BACKGROUND

Hypertension (HTN) is an established class effect of vascular endothelial growth factor receptor (VEGFR) inhibition. In the phase 3 Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) trial, HTN was the most frequent adverse event of lenvatinib, an inhibitor of VEGFR1, VEGFR2, VEGFR3, fibroblast growth factor receptor 1 (FGFR1), FGFR2, FGFR3, FGFR4, platelet-derived growth factor receptor α (PDGFRα), ret proto-oncogene (RET), and stem cell factor receptor (KIT). This exploratory analysis examined treatment-emergent hypertension (TE-HTN) and its relation with lenvatinib efficacy and safety in SELECT.

METHODS

In the multicenter, double-blind SELECT trial, 392 patients with progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC) were randomized 2:1 to lenvatinib (24 mg/d on a 28-day cycle) or placebo. Survival endpoints were assessed with Kaplan-Meier estimates and log-rank tests. The influence of TE-HTN on progression-free survival (PFS) and overall survival (OS) was analyzed with univariate and multivariate Cox proportional hazards models.

RESULTS

Overall, 73% of lenvatinib-treated patients and 15% of placebo-treated patients experienced TE-HTN. The median PFS for lenvatinib-treated patients with (n = 190) and without TE-HTN (n = 71) was 18.8 and 12.9 months, respectively (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.39-0.88; P = .0085). For lenvatinib-treated patients, the objective response rate was 69% with TE-HTN and 56% without TE-HTN (odds ratio, 1.72; 95% CI, 0.98-3.01). The median change in tumor size for patients with and without TE-HTN was -45% and -40%, respectively (P = .2). The median OS was not reached for patients with TE-HTN; for those without TE-HTN, it was 21.7 months (HR, 0.43; 95% CI, 0.27-0.69; P = .0003).

CONCLUSIONS

Although HTN is a clinically significant adverse event that warrants monitoring and management, TE-HTN was significantly correlated with improved outcomes in patients with RR-DTC, indicating that HTN may be predictive for lenvatinib efficacy in this population. Cancer 2018;124:2365-72. © 2018 American Cancer Society.

Early onset of hypertension and serum electrolyte changes as potential predictive factors of activity in advanced HCC patients treated with sorafenib: results from a retrospective analysis of the HCC-AVR group

Hypertension (HTN) is frequently associated with the use of angiogenesis inhibitors targeting the vascular endothelial growth factor pathway and appears to be a generalized effect of this class of agent. We investigated the phenomenon in 61 patients with advanced hepatocellular carcinoma (HCC) receiving sorafenib. Blood pressure and plasma electrolytes were measured on days 1 and 15 of the treatment. Patients with sorafenib-induced HTN had a better outcome than those without HTN (disease control rate: 63.4% vs. 17.2% (p=0.001); progression-free survival 6.0 months (95% CI 3.2-10.1) vs. 2.5 months (95% CI 1.9-2.6) (p<0.001) and overall survival 14.6 months (95% CI9.7-19.0) vs. 3.9 months (95% CI 3.1-8.7) (p=0.003). Sodium levels were generally higher on day 15 than at baseline (+2.38, p<0.0001) in the group of responders (+4.95, p <0.0001) compared to patients who progressed (PD) (+0.28, p=0.607). In contrast, potassium was lower on day 14 (−0.30, p=0.0008) in the responder group (−0.58, p=0.003) than in those with progressive disease (−0.06, p=0.500). The early onset of hypertension is associated with improved clinical outcome in HCC patients treated with sorafenib. Our data are suggestive of an activation of the renin-angiotensin system in patients with advanced disease who developed HTN during sorafenib treatment.

[Side effect management of tyrosine kinase inhibitors in urology : Hypertension]

Tyrosine kinase inhibitors like sunitinib, sorafenib, pazopanib or axintinib are regarded the standard of care in the systemic therapy of metastatic renal cell carcinoma. However, the many side effects associated with this therapy pose challenges for the treating physician and the patient. This review offers an overview of the classification and the treatment of hypertension, which is one of the major side effects induced by all tyrosine kinase inhibitors, in order to improve treatment efficacy and patient compliance.

Effects of human umbilical cord blood-derived mesenchymal stromal cells and dermal fibroblasts on diabetic wound healing

BACKGROUND AIMS

A previous study demonstrated that human umbilical cord blood-derived mesenchymal stromal cells (hUCB-MSCs) have superior wound-healing activity compared with fibroblasts in vitro. However, wound healing in vivo is a complex process that involves multiple factors. The purpose of this study was to compare the effects of hUCB-MSCs and fibroblasts on diabetic wound healing in vivo. This study especially focused on collagen synthesis and angiogenesis, which are considered to be the important factors affecting diabetic wound healing.

METHODS

Porous polyethylene discs were loaded with either fibroblasts or hUCB-MSCs, and a third group, which served as a control, was not loaded with cells. The discs were then implanted in the back of diabetic mice. During the first and the second week after implantation, the discs were harvested, and collagen level and microvascular density were compared.

RESULTS

In terms of collagen synthesis, the hUCB-MSC group showed the highest collagen level (117.7 ± 8.9 ng/mL), followed by the fibroblast group (83.2 ± 5.2 ng/mL) and the no-cell group (60.0 ± 4.7 ng/mL) in the second week after implantation. In terms of angiogenesis, the microvascular density in the hUCB-MSC group was 56.8 ± 16.4, which was much higher than that in the fibroblast group (14.3 ± 4.0) and the no-cell group (5.7 ± 2.1) in the second week after implantation.

CONCLUSIONS

These results demonstrate that hUCB-MSCs are superior to fibroblasts in terms of their effect on diabetic wound healing in vivo.

Pulp bleeding color is an indicator of clinical and histohematologic status of primary teeth

OBJECTIVES

This study was carried out to investigate whether the changes in hematologic characteristic and color of pulpal bleeding is associated with clinical and histologic status of the pulp in primary teeth.

MATERIALS AND METHODS

A total of 211 primary molars in 103 patients, 3-6 years old, were treated. One hundred eight teeth had pulpectomy, 57 teeth had pulpotomy after pulp exposure during caries excavation, and 46 teeth had pulpotomy after accidental pulp exposure in sound dentin. After pulpal exposure, pulpal blood was collected in capillary tubes for blood color and hematologic assessment. Coronal and radicular pulp tissues were amputated for histologic assessment.

RESULTS

Blood color was significantly darker in pulpectomy cases and samples with severe inflammation. The differences were clinically perceptible by the human eye. A significant negative correlation was detected between white blood cell (WBC) count and blood color. The counts of neutrophils and lymphocytes were significantly different between treatment groups. In addition, WBC, eosinophil, monocyte, neutrophil, and basophils counts were significantly different between degrees of inflammation in coronal pulp. Moreover, severe inflammation was higher in pulpectomy group versus pulpotomy groups. Pulp tissue calcification was also significantly higher in the pulpectomy cases.

CONCLUSIONS

Considering the significant difference in pulpal blood color between the pulpectomy and pulpotomy cases, and between the different levels of pulpal inflammation; blood color can be a valid clinical diagnostic criterion of pulpal status and can be used for the selection of appropriate pulp treatment strategy.

CLINICAL RELEVANCE

This study shows that pulp bleeding color can be used for selection of an appropriate pulp treatment method in primary teeth.

Developmental toxicity of 2,4-dichlorophenoxyacetic acid in zebrafish embryos

2,4-Dichlorophenoxyacetic acid (2,4-D) is widely used in agriculture as herbicide/pesticide, plant growth regulator and fruit preservative agent. It progressively accumulates in the environment including surface water, air and soil. It could be detected in human food and urine, which poses great risk to the living organisms. In the present study, we investigated the developmental toxicity of 2,4-D on zebrafish (Danio rerio) embryo. 2,4-D exposure significantly decreased both the survival rate (LC₅₀ = 46.71 mg/L) and hatching rate (IC₅₀ = 46.26 mg/L) of zebrafish embryos. The most common developmental defect in 2,4-D treated embryos was pericardial edema. 2,4-D (25 mg/L) upregulated marker genes of cardiac development (vmhc, amhc, hand2, vegf, and gata1) and downregulated marker genes of oxidative stress (cat and gpx1a). Whole mount in situ hybridization confirmed the vmhc and amhc upregulation by 2,4-D treatment. LC/MS/MS showed that the bioaccumulation of 2,4-D in zebrafish embryos were increased in a time-dependent manner after 25 mg/L of 2,4-D treatment. Taken together, our study investigated the toxic effects of 2,4-D on zebrafish embryonic development and its potential molecular mechanisms, gave evidence for the full understanding of 2,4-D toxicity on living organisms and shed light on its environmental impact.

Microglia preconditioned by oxygen-glucose deprivation promote functional recovery in ischemic rats

Cell-therapies that invoke pleiotropic mechanisms may facilitate functional recovery in stroke patients. We hypothesized that a cell therapy using microglia preconditioned by optimal oxygen-glucose deprivation (OGD) is a therapeutic strategy for ischemic stroke because optimal ischemia induces anti-inflammatory M2 microglia. We first delineated changes in angiogenesis and axonal outgrowth in the ischemic cortex using rats. We found that slight angiogenesis without axonal outgrowth were activated at the border area within the ischemic core from 7 to 14 days after ischemia. Next, we demonstrated that administration of primary microglia preconditioned by 18 hours of OGD at 7 days prompted functional recovery at 28 days after focal cerebral ischemia compared to control therapies by marked secretion of remodelling factors such as vascular endothelial growth factor, matrix metalloproteinase-9, and transforming growth factor-β polarized to M2 microglia in vitro/vivo. In conclusion, intravascular administration of M2 microglia preconditioned by optimal OGD may be a novel therapeutic strategy against ischemic stroke.

Short-term effects of intravitreal ranibizumab and bevacizumab administration on 24-h ambulatory blood pressure monitoring recordings in normotensive patients with age-related macular degeneration

PurposeTo evaluate effects of intravitreal ranibizumab and bevacizumab administration on ambulatory blood pressure monitoring (ABPM) recordings in normotensive patients with age-related macular degeneration (AMD).Patients and methodsA total of 72 patients (mean age: 61.8(6.2) years, 52.8% were females) diagnosed with AMD were included in this study as divided into ranibizumab (n=34) and bevacizumab (n=38) treatment groups. Twenty-four hour, nighttime, and daytime ABMP values for systolic and diastolic BP were recorded in study groups before and after the third intravitreal injection of ranibizumab or bevacizumab.ResultsRanibizumab injection had no impact on ABPM recordings and dipping status. In the bevacizumab group, increased daytime (129.0(6.6) vs 127.7(6.6) mm Hg, P=0.002) and nighttime systolic (116.9(7.5) vs 112.6(7.1) mmHg, p<0.001) BP and decreased daytime diastolic (80.1(6.5) vs 82.4(6.1)mm Hg, P=0.001) BP were noted in the post-injection period. Also, percentage of non-dippers was significantly increased from 5.3% at pre-injection to 28.9% (P=0.004) at the post-injection period.ConclusionIn conclusion, given that it has no significant impact on ABPM recordings and dipping status, in our study, intravitreal ranibizumab injection may be the better choice in the management of AMD.

Angiotensin Inhibitors as Treatment of Sunitinib/Pazopanib-induced Hypertension in Metastatic Renal Cell Carcinoma

BACKGROUND

Research suggests that baseline use of angiotensin system inhibitors (ASIs) improves outcome in patients with metastatic renal cell carcinoma (mRCC), but it remains unknown whether the type of antihypertensive medication used to initiate management at onset of treatment-induced hypertension (HTN) is associated with outcome. We evaluated the association of ASIs and outcome among patients with mRCC treated with first-line tyrosine kinase inhibitors (TKIs).

PATIENTS AND METHODS

We identified 303 consecutive patients with mRCC who were treated with sunitinib or pazopanib in a single university hospital cancer center. Statistical analyses were performed using the Kaplan-Meier method and Cox regression adjusted for known risk factors.

RESULTS

Progression-free survival (PFS) and overall survival (OS) were similar among patients with baseline HTN (n = 197; 65%) versus patients with no baseline HTN (n = 106; 35%) (PFS; P = .72) (OS; P = .54). There was a significant difference between patients with treatment-induced HTN (n = 110) versus patients with no treatment-induced HTN (n = 193) for PFS (15.6 vs. 6.4 months, respectively; P < .001) and OS (34.9 vs. 13.9 months, respectively; P < .001). Use of ASIs at baseline (n = 126; 41.6%) had no impact on outcome as compared with patients receiving other antihypertensive medication (n = 71; 23.4%) or with patients with no baseline antihypertensive medication (n = 106; 35.0%). Among patients with TKI-induced HTN (n = 110), however, ASI users (n = 91) demonstrated improved OS (37.5 vs. 18.1 months; P = .001) and PFS (17.1 vs. 7.2 months; P = .004) versus ASI nonusers (n = 19), respectively.

CONCLUSION

Our results demonstrate survival benefit for ASI users among patients with TKI-induced HTN. These results, however, require further validation in a prospective setting.

Sunitinib side effects as surrogate biomarkers of efficacy

With the proliferation of treatment options for the management of metastatic renal cell carcinoma (mRCC) over the past decade, predictive markers of response to therapy are becoming increasingly important. Sunitinib is commonly used in the first-line treatment of mRCC. Common mechanism-based adverse events, including hypertension, hypothyroidism, hand-foot syndrome, and neutropenia, have been explored as potential biomarkers of the clinical efficacy of sunitinib in mRCC and are reviewed in this article.

Effects of Toceranib Phosphate on Systolic Blood Pressure and Proteinuria in Dogs

Background

Systemic hypertension and proteinuria are established adverse effects of tyrosine kinase inhibitor treatment in people.

Objective

The objective of this study was to investigate changes in systolic blood pressure and the incidence of proteinuria secondary to treatment with toceranib phosphate in dogs with cancer.

Animals

Twenty‐six control dogs and 30 dogs with cancer were evaluated for the first part of the study (baseline characteristics). For the second part (effect of toceranib phosphate treatment), 48 client‐owned dogs were evaluated, including 20 control dogs and 28 dogs with various types of neoplasia.

Methods

Prospective cohort study. Client‐owned healthy control dogs and dogs with cancer were enrolled. Blood pressure and urine protein:creatinine ratios were measured before treatment and 2 weeks after initiation of toceranib phosphate treatment.

Results

Systolic blood pressure was significantly (P = 0.0013) higher in previously normotensive treatment dogs after initiation of treatment with toceranib phosphate (152 mmHg ± 19) compared to baseline (136 mmHg ± 14). 37% of treated dogs developed SBP ≥ 160 mmHg. The prevalence of systemic hypertension (37%) and proteinuria (21%) at baseline in treatment dogs did not differ from that of age‐matched healthy controls (15% [P = 0.13] and 0% [P = 0.069], respectively).

Conclusions and Clinical Importance

Toceranib phosphate treatment might result in increased systolic blood pressures in dogs. Systemic hypertension should be considered a potential adverse effect of this drug in dogs. Systemic hypertension and proteinuria were detected at clinically relevant frequencies in the dogs with cancer before antineoplastic therapies suggesting that monitoring of these variables might be warranted in this population.

Disorders of Vascular Permeability

The endothelial barrier maintains vascular and tissue homeostasis and modulates many physiological processes, such as angiogenesis. Vascular barrier integrity can be disrupted by a variety of soluble permeability factors, and changes in barrier function can exacerbate tissue damage during disease progression. Understanding endothelial barrier function is critical for vascular homeostasis. Many of the signaling pathways promoting vascular permeability can also be triggered during disease, resulting in prolonged or uncontrolled vascular leak. It is believed that recovery of the normal vasculature requires diminishing this hyperpermeable state. Although the molecular mechanisms governing vascular leak have been studied over the last few decades, recent advances have identified new therapeutic targets that have begun to show preclinical and clinical promise. These approaches have been successfully applied to an increasing number of disease conditions. New perspectives regarding how vascular leak impacts the progression of various diseases are highlighted in this review.

Is change in blood pressure a biomarker of pazopanib and sunitinib efficacy in advanced/metastatic renal cell carcinoma?

AIM

Pazopanib, an oral antiangiogenic agent, is associated with improved outcomes in patients with metastatic renal cell carcinoma. In this retrospective analysis, we explore hypertension, an on-target adverse event, as a predictive marker.

METHODS

Data from the pazopanib arm of the phase III COMPARZ trial (NCT00720941) comprised the test set. Pooled data from phase II (NCT00244764) and III (NCT00334282) pazopanib trials comprised the validation set. Data from the sunitinib arm of COMPARZ were analysed separately. Measures of efficacy were response rate, progression-free survival (PFS), and overall survival (OS). Mean arterial blood pressure (MAP) was the primary metric, and systolic hypertension (S-HTN) and diastolic hypertension (D-HTN) were secondary metrics; 4- and 12-week landmark analyses were performed.

RESULTS

Analyses revealed no significant associations at the landmarks between response and MAP. We observed a trend towards improved PFS with S-HTN at week 4 (hazard ratio [HR] = 0.79, P = 0.060) and week 12 (HR = 0.75, P = 0.073) among pazopanib-treated patients in COMPARZ. This trend was not confirmed at week 12 in the validation set or in sunitinib-treated patients. In the test set, there was a trend towards increased OS in patients with S-HTN by week 4 (HR = 0.76, P = 0.062) and with D-HTN by week 4 (HR = 0.71, P = 0.016) but not by week 12. No significant differences in OS were observed in sunitinib-treated patients for S-HTN or D-HTN.

CONCLUSION

Neither hypertension nor any blood pressure elevation above baseline was associated with efficacy outcomes of pazopanib or sunitinib. Accordingly, management of tyrosine kinase inhibitor-induced hypertension is unlikely to compromise outcome.

Treatment of sunitinib-induced hypertension in solid tumor by nitric oxide donors

Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are overexpressed in the majority of renal cell carcinomas. This characteristic has supported the rationale of targeting VEGF-driven tumour vascularization, especially in clear cell RCC. VEGF-inhibiting strategies include the use of tyrosine kinase inhibitors (sunitinib, axitinib, pazopanib, and sorafenib) and neutralizing antibodies such as bevacizumab.

Hypertension (HTN) is one of the most common adverse effects of angiogenesis inhibitors. HTN observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of HTN. Although the exact mechanism by tyrosine kinase inhibitors induce HTN has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS) and nitric oxide (NO) production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction) occurs upon VEGF signaling inhibition.

NO donors could be successfully used not only for the treatment of developed angiogenesis-inhibitor-induced hypertension but also for preventive effects.

•

Hypertension appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2.

•

Sunitinib is associated with several side effects, with hypertension being the most common one.

•

VEGF inhibitors induce decrease in nitric oxide synthase and nitric oxide production, that can result in vasoconstriction and increased blood pressure.

•

NO donors could be successfully used for the treatment of angiogenesis-inhibitor-induced hypertension and also for preventive effects.

A phase II trial of second-line axitinib following prior antiangiogenic therapy in advanced hepatocellular carcinoma

BACKGROUND

Second-line treatment options in advanced hepatocellular carcinoma (HCC) are limited. Axitinib, a selective potent tyrosine kinase inhibitor (TKI) of vascular endothelial growth factor VEGF) receptors 1, 2, and 3, merits exploration in HCC.

METHODS

This was a single-arm phase II trial of axitinib in advanced HCC. Eligible patients were Child-Pugh A/B7, with measurable progressive disease after TKIs/antiangiogenic drugs. Axitinib was started at 5 mg twice daily orally, titrated from 2 to 10 mg twice daily as tolerated. The primary end point was tumor control at 16 weeks by RECIST1.1; secondary end points were response rate, comparing response by RECIST1.1 to Choi and modified RECIST, exploring dynamic contrast-enhanced imaging models, safety, progression-free (PFS), and overall survival (OS).

RESULTS

Thirty patients were treated. Of 26 patients evaluable for response, there were 3 partial responses (PR) per RECIST1.1; 13 PR by Choi, 6 PR and 1 complete response by modified RECIST. Tumor control rate at 16 weeks was 42.3%. Two-week perfusion changes were noted on functional imaging. Of 21 patients with evaluable α-fetoprotein response, 43% had >50% decrease from baseline. Most common axitinib-related grade 3/4 adverse events (AEs) were hypertension, thrombocytopenia and diarrhea. Of 11 patients with any grade hypertension, 7 had disease control >36 wks. Four patients discontinued treatment due to AEs. Median PFS was 3.6 months. Median OS was 7.1 months.

CONCLUSIONS

With 42.3% tumor control at 16 weeks, primary endpoint was met. Axitinib has shown encouraging tolerable clinical activity in VEGF-pretreated HCC patients but further study should be in a selected population incorporating potential biomarkers of response.

Incidence and management of ZIv-aflibercept related toxicities in colorectal cancer

Ziv-afilbercept (Zaltrap, Ziv) is a humanized fusion protein constructed by joining the vascular endothelial growth factor (VEGF) binding portions of human VEGF receptors 1 and 2 to the Fc portion of human immunoglobulin IgG1. Recently, a randomized, open-label, phase III study compared 5-fluorouracil, leucovorin, irinotecan (FOLFIRI)/Ziv with FOLFIRI/placebo in patients who had been previously treated with oxaliplatin based chemotherapy for metastatic colon cancer (mCRC). Patients who had received prior bevacizumab therapy were also eligible. This study showed that the addition of Ziv improved overall survival with median survival time of 13.5 mo vs 12.06 mo in ziv vs placebo arm. Ziv also improved progression free survival from 4.67 mo to 6.9 mo with a response rate of 19.8% in the Ziv/FOLFIRI group vs 11.1% in FOLFIRI alone group. This led to the approval of Ziv in combination with FOLFIRI in metastatic colon cancer patients treated with prior oxaliplatin regimens. The most common side effects were diarrhea, stomatitis, fatigue, hypertension, weight loss, loss of appetite, abdominal pain, and headache. As the use of Ziv has become more widespread in oncology practices, familiarity with the toxicity profile of the drug and the use of practice guidelines for their treatment has become increasing important. This review will address the toxicities noted in trials using Ziv for the treatment of mCRC, and will provide recommendations for toxicity management.

The contribution of VEGF signalling to fostamatinib-induced blood pressure elevation

BACKGROUND AND PURPOSE

Fostamatinib is an inhibitor of spleen tyrosine kinase (TK). In patients, fostamatinib treatment was associated with increased BP. Some TK inhibitors cause BP elevation, by inhibiting the VEGF receptor 2 (VEGFR2). Here, we have assessed the mechanistic link between fostamatinib-induced BP elevation and inhibition of VEGF signalling.

EXPERIMENTAL APPROACH

We used conscious rats with automated blood sampling and radio telemetry and anaesthetized rats to measure cardiovascular changes. Rat isolated aorta and isolated hearts, and human resistance vessels in vitro were also used. NO production by human microvascular endothelial cells was measured with the NO-dependent probe, DAF-FM and VEGFR2 phosphorylation was determined in mouse lung, ex vivo.

KEY RESULTS

In conscious rats, fostamatinib dose-dependently increased BP. The time course of the BP effect correlated closely with the plasma concentrations of R406 (the active metabolite of fostamatinib). In anaesthetized rats, infusion of R406 increased BP and decreased femoral arterial conductance. Endothelial function was unaffected, as infusion of R406 did not inhibit hyperaemia- or ACh-induced vasodilatation in rats. R406 did not affect contraction of isolated blood vessels. R406 inhibited VEGF-stimulated NO production from human endothelial cells in vitro, and treatment with R406 inhibited VEGFR2 phosphorylation in vivo. R406 inhibited VEGF-induced hypotension in anaesthetized rats.

CONCLUSIONS AND IMPLICATIONS

Increased vascular resistance, secondary to reduced VEGF-induced NO release from endothelium, may contribute to BP increases observed with fostamatanib. This is consistent with the elevated BP induced by other drugs inhibiting VEGF signalling, although the contribution of other mechanisms cannot be excluded.

Pulmonary vascular dysfunction in ARDS

Acute respiratory distress syndrome (ARDS) is characterised by diffuse alveolar damage and is frequently complicated by pulmonary hypertension (PH). Multiple factors may contribute to the development of PH in this setting. In this review, we report the results of a systematic search of the available peer-reviewed literature for papers that measured indices of pulmonary haemodynamics in patients with ARDS and reported on mortality in the period 1977 to 2010. There were marked differences between studies, with some reporting strong associations between elevated pulmonary arterial pressure or elevated pulmonary vascular resistance and mortality, whereas others found no such association. In order to discuss the potential reasons for these discrepancies, we review the physiological concepts underlying the measurement of pulmonary haemodynamics and highlight key differences between the concepts of resistance in the pulmonary and systemic circulations. We consider the factors that influence pulmonary arterial pressure, both in normal lungs and in the presence of ARDS, including the important effects of mechanical ventilation. Pulmonary arterial pressure, pulmonary vascular resistance and transpulmonary gradient (TPG) depend not alone on the intrinsic properties of the pulmonary vascular bed but are also strongly influenced by cardiac output, airway pressures and lung volumes. The great variability in management strategies within and between studies means that no unified analysis of these papers was possible. Uniquely, Bull et al. (Am J Respir Crit Care Med 182:1123-1128, 2010) have recently reported that elevated pulmonary vascular resistance (PVR) and TPG were independently associated with increased mortality in ARDS, in a large trial with protocol-defined management strategies and using lung-protective ventilation. We then considered the existing literature to determine whether the relationship between PVR/TPG and outcome might be causal. Although we could identify potential mechanisms for such a link, the existing evidence does not allow firm conclusions to be drawn. Nonetheless, abnormally elevated PVR/TPG may provide a useful index of disease severity and progression. Further studies are required to understand the role and importance of pulmonary vascular dysfunction in ARDS in the era of lung-protective ventilation.

Local over-expression of VEGF-DΔNΔC in the uterine arteries of pregnant sheep results in long-term changes in uterine artery contractility and angiogenesis

Background

The normal development of the uteroplacental circulation in pregnancy depends on angiogenic and vasodilatory factors such as vascular endothelial growth factor (VEGF). Reduced uterine artery blood flow (UABF) is a common cause of fetal growth restriction; abnormalities in angiogenic factors are implicated. Previously we showed that adenovirus (Ad)-mediated VEGF-A₁₆₅ expression in the pregnant sheep uterine artery (UtA) increased nitric oxide synthase (NOS) expression, altered vascular reactivity and increased UABF. VEGF-D is a VEGF family member that promotes angiogenesis and vasodilatation but, in contrast to VEGF-A, does not increase vascular permeability. Here we examined the effect of Ad.VEGF-D^ΔNΔC vector encoding a fully processed form of VEGF-D, on the uteroplacental circulation.

Methods

UtA transit-time flow probes and carotid artery catheters were implanted in mid-gestation pregnant sheep (n = 5) to measure baseline UABF and maternal haemodynamics respectively. 7–14 days later, after injection of Ad.VEGF-D^ΔNΔC vector (5×10¹¹ particles) into one UtA and an Ad vector encoding β-galactosidase (Ad.LacZ) contralaterally, UABF was measured daily until scheduled post-mortem examination at term. UtAs were assessed for vascular reactivity, NOS expression and endothelial cell proliferation; NOS expression was studied in ex vivo transduced UtA endothelial cells (UAECs).

Results

At 4 weeks post-injection, Ad.VEGF-D^ΔNΔC treated UtAs showed significantly lesser vasoconstriction (E_max144.0 v/s 184.2, p = 0.002). There was a tendency to higher UABF in Ad.VEGF-D^ΔNΔC compared to Ad.LacZ transduced UtAs (50.58% v/s 26.94%, p = 0.152). There was no significant effect on maternal haemodynamics. An increased number of proliferating endothelial cells and adventitial blood vessels were observed in immunohistochemistry. Ad.VEGF-D^ΔNΔC expression in cultured UAECs upregulated eNOS and iNOS expression.

Conclusions

Local over-expression of VEGF-D^ΔNΔC in the UtAs of pregnant mid-gestation sheep reduced vasoconstriction, promoted endothelial cell proliferation and showed a trend towards increased UABF. Studies in cultured UAECs indicate that VEGF-D^ΔNΔC may act in part through upregulation of eNOS and iNOS.

Biomarkers of endothelial dysfunction in preeclampsia and neonatal morbidity: a case-control study

OBJECTIVE

To investigate the association of preeclampsia with angiogenic imbalance, and the correlation of levels of angiogenic and anti-angiogenic factors to complications in mother and fetus.

STUDY DESIGN

Serum samples were obtained from 40 women with established preeclampsia (study group) and from 40 normotensive women (control group). Epidemiological characteristics of the two groups were analyzed. The levels of the angiogenic (VEGF and PlGF) and anti-angiogenic (sFlt-1) factors of the two study groups were determined in serum using ELISA. Neonatal adverse outcomes (late preterm, early term, low birth weight (LBW), very LBW (VLBW), intrauterine growth restriction (IUGR), and neonatal intensive care unit (NICU) admission) between the groups of the study were analyzed, as well as the association between the biomarkers of the study and neonatal adverse outcomes of the preeclamptic group of patients.

RESULTS

sFlt-1 levels were significantly higher in the preeclamptic women compared to normotensive women (median (range): 21297 (690-32637)pg/ml vs. 846.45 (363-2867)pg/ml, respectively), whereas there was a significant decrease in the levels of VEGF (90 (90-211)pg/ml vs. 90.55 (90-521)pg/ml, respectively), as well as in the levels of PlGF (13.62 (8-532)pg/ml vs. 239.86 (61-685)pg/ml, respectively). The increased serum values of the anti-angiogenic sFlt-1 were associated with increased rates of late preterm and early term births and VLBW.

CONCLUSION

An imbalance between angiogenic and anti-angiogenic factors exists in preeclampsia and is associated with adverse maternal and neonatal outcomes.

Vascular endothelial growth factor inhibitor-induced hypertension: from pathophysiology to prevention and treatment based on long-acting nitric oxide donors

Hypertension is the most common adverse effect of the inhibitors of vascular endothelial growth factor (VEGF) pathway-based therapy (VEGF pathway inhibitors therapy, VPI therapy) in cancer patients. VPI includes monoclonal antibodies against VEGF, tyrosine kinase inhibitors, VEGF Traps, and so-called aptamers that may become clinically relevant in the future. All of these substances inhibit the VEGF pathway, which in turn causes a decrease in nitric oxide (NO) and an increase in blood pressure, with the consequent development of hypertension and its final events (e.g., myocardial infarction or stroke). To our knowledge, there is no current study on how to provide an optimal therapy for patients on VPI therapy with hypertension. This review summarizes the roles of VEGF and NO in vessel biology, provides an overview of VPI agents, and suggests a potential treatment procedure for patients with VPI-induced hypertension.

Quantitative high-throughput profiling of snake venom gland transcriptomes and proteomes (Ovophis okinavensis and Protobothrops flavoviridis)

Background

Advances in DNA sequencing and proteomics have facilitated quantitative comparisons of snake venom composition. Most studies have employed one approach or the other. Here, both Illumina cDNA sequencing and LC/MS were used to compare the transcriptomes and proteomes of two pit vipers, Protobothrops flavoviridis and Ovophis okinavensis, which differ greatly in their biology.

Results

Sequencing of venom gland cDNA produced 104,830 transcripts. The Protobothrops transcriptome contained transcripts for 103 venom-related proteins, while the Ovophis transcriptome contained 95. In both, transcript abundances spanned six orders of magnitude. Mass spectrometry identified peptides from 100% of transcripts that occurred at higher than contaminant (e.g. human keratin) levels, including a number of proteins never before sequenced from snakes. These transcriptomes reveal fundamentally different envenomation strategies. Adult Protobothrops venom promotes hemorrhage, hypotension, incoagulable blood, and prey digestion, consistent with mammalian predation. Ovophis venom composition is less readily interpreted, owing to insufficient pharmacological data for venom serine and metalloproteases, which comprise more than 97.3% of Ovophis transcripts, but only 38.0% of Protobothrops transcripts. Ovophis venom apparently represents a hybrid strategy optimized for frogs and small mammals.

Conclusions

This study illustrates the power of cDNA sequencing combined with MS profiling. The former quantifies transcript composition, allowing detection of novel proteins, but cannot indicate which proteins are actually secreted, as does MS. We show, for the first time, that transcript and peptide abundances are correlated. This means that MS can be used for quantitative, non-invasive venom profiling, which will be beneficial for studies of endangered species.

The Key Role of the Blood Supply to Bone

The importance of the vascular supply for bone is well-known to orthopaedists but is still rather overlooked within the wider field of skeletal research. Blood supplies oxygen, nutrients and regulatory factors to tissues, as well as removing metabolic waste products such as carbon dioxide and acid. Bone receives up to about 10% of cardiac output, and this blood supply permits a much higher degree of cellularity, remodelling and repair than is possible in cartilage, which is avascular. The blood supply to bone is delivered to the endosteal cavity by nutrient arteries, then flows through marrow sinusoids before exiting via numerous small vessels that ramify through the cortex. The marrow cavity affords a range of vascular niches that are thought to regulate the growth and differentiation of hematopoietic and stromal cells, in part via gradients of oxygen tension. The quality of vascular supply to bone tends to decline with age and may be compromised in common pathological settings, including diabetes, anaemias, chronic airway diseases and immobility, as well as by tumours. Reductions in vascular supply are associated with bone loss. This may be due in part to the direct effects of hypoxia, which blocks osteoblast function and bone formation but causes reciprocal increases in osteoclastogenesis and bone resorption. Common regulatory factors such as parathyroid hormone or nitrates, both of which are potent vasodilators, might exert their osteogenic effects on bone via the vasculature. These observations suggest that the bone vasculature will be a fruitful area for future research.

Spatiotemporal control of vascular endothelial growth factor expression using a heat-shock-activated, rapamycin-dependent gene switch

A major challenge in regenerative medicine is to develop methods for delivering growth and differentiation factors in specific spatial and temporal patterns, thereby mimicking the natural processes of development and tissue repair. Heat shock (HS)-inducible gene expression systems can respond to spatial information provided by localized heating, but are by themselves incapable of sustained expression. Conversely, gene switches activated by small molecules provide tight temporal control and sustained expression, but lack mechanisms for spatial targeting. Here we combine the advantages of HS and ligand-activated systems by developing a novel rapamycin-regulated, HS-inducible gene switch that provides spatial and temporal control and sustained expression of transgenes such as firefly luciferase and vascular endothelial growth factor (VEGF). This gene circuit exhibits very low background in the uninduced state and can be repeatedly activated up to 1 month. Furthermore, dual regulation of VEGF induction in vivo is shown to stimulate localized vascularization, thereby providing a route for temporal and spatial control of angiogenesis.

Effects of androgen on vascular and inflammatory biomarkers in a female hypertensive population

BACKGROUND

Androgen is a steroid hormone associated with high blood pressure (BP). The effect of androgen on BP in females is unknown.

METHODS

Androgen, vascular endothelial growth factor (VEGF), interleukin (IL)-6 and matrix metalloproteinase (MMP)-9 were evaluated in females with menstruation disorders (n = 135, 28 ± 5 years old) and normal BP, pre-hypertension, stage 1 hypertension, and stage 2 hypertension.

RESULTS

Normal-BP (n = 57), pre-hypertension (n = 44), stage-1-hypertension (n = 21), and stage-2-hypertension (n = 13) females had similar androgen (3.3 ± 1.5, 2.7 ± 1.2, 3.1 ± 1.4, and 3.5 ± 1.3 ng/ml, p > 0.05) and IL-6 levels (1.7 ± 2.2, 1.9 ± 2.6, 1.3 ± 1.2 and 2.4 ± 3.3 pg/ml, p > 0.05). However, normal BP females had lower MMP-9 (609 ± 307 versus 891 ± 385 ng/ml, p < 0.05) than stage-1-hypertension females. In addition, normal BP females had lower VEGF (166 ± 103 versus 255 ± 139, 272 ± 128 and 301 ± 216 pg/ml, p < 0.05) than the other three groups. In normal-androgen females, VEGF levels were similar among the four groups. However, in high-androgen females, normal BP groups had lower VEGF levels than pre-hypertension, stage-1, and stage-2 hypertension groups (166 ± 94 versus 294 ± 153, 281 ± 160 and 357 ± 253 p < 0.05).

CONCLUSIONS

Androgen can modulate growth factors and extracellular matrix proteins, which may contribute to the pathophysiology of hypertension in young females.

Bevacizumab use and risk of cardiovascular adverse events among elderly patients with colorectal cancer receiving chemotherapy: a population-based study

BACKGROUND

Cardiovascular risk attributable to bevacizumab (Avastin(®), BEV) for treatment of metastatic colorectal cancer (CRC) remains unclear. We conducted a population-based cohort study to assess the safety of BEV use among patients aged ≥ 65.

PATIENTS AND METHODS

We identified CRC patients diagnosed from 2005 to 2007 who received chemotherapy and were followed until 31 December 2009. Outcomes were 3-year risk of arterial thromboembolic events (ATEs), cardiomyopathy or congestive heart failure (CM/CHF), and cardiac death (CD) after chemotherapy initiation. We fitted Cox-proportional hazards (PHs) models with inverse-probability-of-treatment-weights and calculated hazard ratios (HRs) for the risk of adverse events.

RESULTS

We identified 6803 CRC patients (median age: 73 years). Those with cardiac comorbidity were less likely to receive BEV (P < 0.0001). BEV is associated with an elevated risk of ATEs (HR = 1.82, 95% CI = 1.20-2.76, P < 0.001; rate difference: 3.5 additional cases/1000 person-years). We observed no association between BEV and CD or CM/CHF.

CONCLUSIONS

In general practice, the cardiovascular risk of BEV in elderly CRC is modest. The observed ATEs risk is lower than reported in clinical trials, which may be due to careful patient selection. Our findings may facilitate clinical decision-making of BEV use in elderly patients.

Expression of growth factors during the healing process of alveolar ridge augmentation procedures using autogenous bone grafts in combination with GTR and an anorganic bovine bone substitute: an immunohistochemical study in the sheep

OBJECTIVES

This study aims to evaluate the expression of various immunohistochemical growth factors and vascularization markers in augmentation on the mandible comparing onlay bone grafts and Guided Bone Regeneration (GBR).

MATERIALS AND METHODS

Using a sheep in vivo model, autogenous bone grafts were harvested from the iliac crest. A combination of a resorbable collagen membrane (CM) and a Deproteinized Bovine Bone Material (DBBM) was performed. This modification of the host side was compared with an onlay bone graft control group. Expression of different vascularization markers was compared between these groups.

RESULTS

The expression of revascularization markers was significantly higher within the modification of the host side using GBR and DBBM. Regarding different graft regions, a significantly higher expression within the bone graft using GBR and DBBM could be observed in staining on bone morphogenetic protein-2 (BMP-2) (5.75 vs. 3.55), vascular endothelial growth factor (VEGF) (3.08 vs. 1.64), VEGF Receptor 1 (VEGFR-1) and VEGF Receptor 2 (VEGFR-2) (4.88 vs. 2.24 and 5.06 vs. 2.74), and endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) (5.29 vs. 3.28 and 5.22 vs. 3.09; p = 0.000, all others p < 0.05), whereas the control group showed a higher rate of resorption during the surveillance period until euthanasia of sheep after 16 weeks.

CONCLUSION

The use of GBR and DBBM in the transplantation process of autogenous bone grafts compared with the therapeutical use of certain growth factors may enhance vascularization and lower atrophy and resorption.

CLINICAL RELEVANCE

The use of a combination of GBR and DBBM in augmentation procedures on the mandible shows less resorption than simple onlay bone grafts and seems to be superior in a clinical use.

Response of HT29 colorectal xenograft model to cediranib assessed with 18 F-fluoromisonidazole positron emission tomography, dynamic contrast-enhanced and diffusion-weighted MRI

Cediranib is a small-molecule pan-vascular endothelial growth factor receptor inhibitor. The tumor response to short-term cediranib treatment was studied using dynamic contrast-enhanced and diffusion-weighted MRI at 7 T, as well as (18) F-fluoromisonidazole positron emission tomography and histological markers. Rats bearing subcutaneous HT29 human colorectal tumors were imaged at baseline; they then received three doses of cediranib (3 mg/kg per dose daily) or vehicle (dosed daily), with follow-up imaging performed 2 h after the final cediranib or vehicle dose. Tumors were excised and evaluated for the perfusion marker Hoechst 33342, the endothelial cell marker CD31, smooth muscle actin, intercapillary distance and tumor necrosis. Dynamic contrast-enhanced MRI-derived parameters decreased significantly in cediranib-treated tumors relative to pretreatment values [the muscle-normalized initial area under the gadolinium concentration curve decreased by 48% (p=0.002), the enhancing fraction by 43% (p=0.003) and K(trans) by 57% (p=0.003)], but remained unchanged in controls. No change between the pre- and post-treatment tumor apparent diffusion coefficients in either the cediranib- or vehicle-treated group was observed over the course of this study. The (18) F-fluoromisonidazole mean standardized uptake value decreased by 33% (p=0.008) in the cediranib group, but showed no significant change in the control group. Histological analysis showed that the number of CD31-positive vessels (59 per mm(2) ), the fraction of smooth muscle actin-positive vessels (80-87%) and the intercapillary distance (0.17 mm) were similar in cediranib- and vehicle-treated groups. The fraction of perfused blood vessels in cediranib-treated tumors (81 ± 7%) was lower than that in vehicle controls (91 ± 3%, p=0.02). The necrotic fraction was slightly higher in cediranib-treated rats (34 ± 12%) than in controls (26 ± 10%, p=0.23). These findings suggest that short-term treatment with cediranib causes a decrease in tumor perfusion/permeability across the tumor cross-section, but changes in vascular morphology, vessel density or tumor cellularity are not manifested at this early time point.