Anti-Vascular Endothelial Growth Factor Therapy Abolishes Glioma-Associated Endothelial Cell-Induced Tumor Invasion.

Tumor-remodeled endothelial cells not only facilitate the formation of tumor angiogenesis but also promote tumorigenesis. In this study, we aimed to explore the interaction between glioma-associated endothelial cells (GAEs) and glioma cells. We found that different subtypes of glioma owned distinct GAE abundance. Glioma patients with high GAE abundance exhibited poor prognosis. Both the results of the bioinformatics analysis and the in vitro co-culture system assay revealed that GAE promoted glioma cell invasion. Besides, anti-vascular endothelial growth factor (VEGF) therapy partially abolished the effects of GAE on gliomas. Moreover, anti-VEGF therapy upregulated IL-2 expression in GAE, and exogenous IL-2 administration inhibits GAE-induced glioma cell invasion. Collectively, our present study provides a novel outstanding of the interaction between GAE and glioma cells.

Determination of the effectiveness of Dorema ammoniacum gum on wound healing: an experimental study.

OBJECTIVE: For a long time, natural compounds have been used to accelerate wound healing. In this study, the topical effects of ammoniacum gum extract on wound healing were investigated in white male rats. METHOD: Following skin wound induction in aseptic conditions, 48 Wistar rats were divided into six equal groups; phenytoin cream 1% (standard), untreated (control), Eucerin (control), and 5%, 10% and 20% ointments of Dorema ammoniacum gum extract (treatment groups). All experimental groups received topical drugs daily for 14 days. The percentage of wound healing, hydroxyproline content, histological parameters, and growth factors (endothelial growth factor (EGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-α) were measured in experimental groups. RESULTS: The areas of the wounds in the treatment groups were significantly decreased compared with the wound areas of control groups at 5, 7 and 10 days after wounding. On the 12th day, the wounds in the treatment groups were completely healed. Hydroxyproline contents were significantly increased in the treatment groups compared with the control groups (p<0.001). In histological evaluation, the re-epithelialisation, increasing thickness of the epithelial layer, granulation tissue and neovascularisation parameters in the treatment groups showed significant increases compared with the control groups. Also, serum levels of TGF-ß, PDGF, EGF and VEGF in the treatment groups were significantly increased compared to the control groups. CONCLUSION: The topical application of ammoniacum gum extract significantly increases the percentage of wound healing in rats and reduces the time of wound closure.

Plasma Levels and Diagnostic Significance of miR-335-3p and EGFR in Diabetic Retinopathy.

BACKGROUND: Diabetic retinopathy (DR) is the common complication of diabetes, accounting for most blindness cases worldwide. MicroRNAs (miRs) are small non-coding RNAs and participate in the pathogenesis and develop-ment of various diseases, including DR. The present study aimed to investigate miR-335-3p and vascular endothelial growth factor (EGFR) roles in DR diagnosis and development. METHODS: A total of 104 healthy volunteers, 96 type 2 diabetes mellitus (T2DM) patients, and 102 DR cases were enrolled in this study. The clinicopathological information of all subjects were collected and analyzed using chisquared test. After collecting plasma from each participant, a ROC assay was conducted to determine the dis-criminative value of miR-335-3p and EGFR in DR diagnosis. The targeted relationship between miR-335-3p and EGFR was examined by dual-luciferase reporter assay and correlation analysis. After exposing APRE-19 cells to different concentrations of high glucose (HG), the DR in vitro cell model was constructed. The expression levels of miR-335-3p and EGFR were detected using RT-qPCR. The effects of miR-335-3p and EGFR on HG-treated APRE-19 cell viability were determined by CCK-8 assay. RESULTS: Clinicopathological information presented that BMI index, fasting blood glucose (FBP), 2h-BG, HbA1c, miR-335-3p, and EGFR levels were strongly associated with DR pathogenesis. MiR-335-3p was significantly decreased while EGFR was increased in DR patients and HG-treated APRE-19 cells. MiR-335-3p and EGFR presented high accuracy, sensitivity, and specificity in differentiating DR from healthy cases and T2DM patients; moreover, miR-335-3p and EGFR could also discriminate proliferative DR (PDR) cases from healthy controls. After confirming that miR-335-3p was negatively correlated with its target EGFR, we found miR-335-3p could increase the viability in HG-treated APRE-19 cells while silencing of EGFR could also reverse the inhibitory effects of HG conditions on APRE-19 cell viability. CONCLUSIONS: We concluded that plasma miR-335-3p and EGFR may be utilized as non-invasive biomarkers for screening DR cases, contributing to DR diagnosis and treatment.

Choroidal Vascularity Index as a Biomarker for Visual Response to Antivascular Endothelial Growth Factor Treatment in Diabetic Macular Edema.

PURPOSE: To investigate the choroidal vascularity index (CVI) as a prognostic factor for the visual efficacy of antivascular endothelial growth factor (VEGF) treatment in diabetic macular edema (DME). METHODS: We retrospectively reviewed 92 DME eyes receiving anti-VEGF treatment, which were stratified as responders (≥5 letters gained) and nonresponders (<5 letters gained or lost). Baseline systematic features and optical coherence tomography features, including the CVI, adjusted ellipsoid zone (EZ) reflectivity, subretinal fluid (SRF), and disorganization of the retinal inner layers (DRIL), were evaluated between the two groups. RESULTS: The baseline CVI was significantly lower in nonresponders than in responders (0.66 ± 0.05, 0.69 ± 0.05, and 0.72 ± 0.05, p = 0.014). After adjusting for other factors, the baseline CVI, DRIL, SRF, and adjusted EZ reflectivity were significantly associated with visual outcomes (CVI: odds ratio (OR) = 0.17, p = 0.006; adjusted EZ reflectivity: OR = 0.56, p = 0.007; DRIL: OR = 6.71, p = 0.001; and SRF: OR = 0.29, p = 0.008). CONCLUSION: DME patients with a higher CVI, higher adjusted EZ reflectivity, the presence of SRF, and the absence of DRIL at baseline were more likely to gain >5 letters in visual acuity after anti-VEGF treatment. CVI may serve as a novel biomarker for visual response to anti-VEGF treatment in DME.

Anatomic-Functional Correlates in Lesions of Retinal Vein Occlusion.

Purpose: To evaluate anatomic-functional associations at sites of retinal lesions in retinal vein occlusion (RVO). Methods: This pilot, prospective, observational study was conducted at the Northern Ireland Clinical Research Facility (NICRF) of Queen's University and the Belfast Health and Social Care Trust, Northern Ireland, between August 1, 2018, and September 30, 2019. The study included 10 treatment-naïve patients with RVO (10 RVO eyes and 10 fellow eyes). There were 81 points/sites assessed for each eye at baseline; six patients were re-assessed 6 months after anti-vascular endothelial growth factor therapy at the same locations. We investigated associations between retinal sensitivity and presence of structural RVO lesions, including retinal ischemia, hemorrhages, intraretinal fluid (IRF) and subretinal fluid outside the foveal/parafoveal regions. Comparisons were made between RVO eyes and fellow eyes at baseline, and between RVO eyes at baseline and at 6 months after treatment. Regression models were used to investigate anatomic-functional associations. Results: At baseline, strong associations were found between reduced retinal sensitivity and presence of ischemia (estimate = -2.08 dB; P < 0.001), intraretinal fluid (estimate = -7.82 dB; P < 0.001), and subretinal fluid (estimate = -8.66 dB; P < 0.001). Resolution of subretinal fluid but not intraretinal fluid was associated with improved function (estimate = 2.40 dB [P = 0.022]; estimate = 1.16 dB [P = 0.228], respectively). However, reperfusion of ischemic retina, observed in 31 of 486 points (6%) 6 months after anti-vascular endothelial growth factor therapy, was associated with a further decrease in retinal sensitivity (estimate = -2.34 dB; P = 0.035). Conclusions: Retinal sensitivity was decreased at sites of RVO lesions. Decreased function at sites of retinal ischemia did not recover after treatment, even when reperfusion occurred.

Corneal Recovery Following Rabbit Peripheral Blood Mononuclear Cell-Amniotic Membrane Transplantation with Antivascular Endothelial Growth Factor in Limbal Stem Cell Deficiency Rabbits.

Background: Limbal stem cell deficiency (LSCD) is a refractory ocular surface disorder characterized by progressive corneal epithelial degeneration, conjunctivalization, and neovascularization, potentially leading to blindness. There are currently no effective therapeutic options for patients experiencing routine symptomatic treatment failure. Transplantation of amniotic membrane (AM) with adherent stem cells (but not bare AM transplantation alone) has shown promise in preclinical studies for ocular surface restoration. A major limitation, however, is finding a reliable stem cell source. Stem cells can be isolated from the peripheral blood mononuclear cell (PBMC) population, and these PBMC-derived stem cells have numerous advantages over allogeneic and other autologous stem cell types for therapeutic application, including relative ease of acquisition, nonimmunogenicity, and the absence of ethical issues associated with embryonic stem cells. Experiment: We examined the efficacy of autologous PBMC-AM sheet cultures combined with postoperative antiangiogenesis treatment for corneal restoration in LSCD model rabbits. Rabbit PBMCs (rPBMCs) were isolated, labeled with EdU for in vivo tracing, and then cultured on AMs in conditioned medium before transplantation. Rabbits were transplanted with bare AMs (group 1), rPBMC-AM sheets (group 2), or rPBMC-AM sheets plus postoperative treatment with the vascular endothelial growth factor antagonist bevacizumab (group 3). Corneal opacity and neovascularization were monitored by slit-lamp imaging for 8 weeks and corneas were examined histologically at 1 and 2 months. Results: Corneal opacity decreased in all three groups over 8 weeks, but was significantly lower in group 2 and even lower in group 3. Corneal neovascularization was significantly higher in group 1 throughout the observation period, and significantly lower in group 3 than group 1 and 2 by 8 weeks post-transplant. At 4 weeks, the corneal surface completed epithelialization (although thinner than normal) in group 3 but still patchy in groups 1 and 2. By 8 weeks, the epithelium in group 3 was complete and smooth, resembling a normal epithelium. Integrin ß1 as a progenitor marker was also generally higher in groups 2 and 3. Conclusions: Autologous rPBMC-AM sheets with post-transplant topical bevacizumab can effectively facilitate corneal epithelium recovery in a LSCD model, suggesting clinical utility for LSCD-related ocular surface diseases. Impact statement Limbal stem cell deficiency (LSCD) increases corneal opacity and vascularization, resulting in severe visual impairment or even blindness. Traditional surgical limbal transplant is currently the main treatment option for LSCD, but carries the risks of rejection and immunosuppressant side effects. Autologous stem cell-based therapy is a promising alternative approach, but a reliable stem cell source is a major limitation. We report that transplantation of autologous rabbit peripheral blood mononuclear cell-amniotic membrane sheets plus antivascular endothelial growth factor restored avascular transparent cornea in a rabbit LSCD model. These results demonstrate a potentially effective approach for ocular surface reconstruction in bilateral LSCD.

PI3Kδ as a Novel Therapeutic Target in Pathological Angiogenesis.

Diabetic retinopathy is the most common microvascular complication of diabetes, and in the advanced diabetic retinopathy appear vitreal fibrovascular membranes that consist of a variety of cells, including vascular endothelial cells (ECs). New therapeutic approaches for this diabetic complication are urgently needed. Here, we report that in cultured human retinal microvascular ECs, high glucose induced expression of p110δ, which was also expressed in ECs of fibrovascular membranes from patients with diabetes. This catalytic subunit of a receptor-regulated PI3K isoform δ is known to be highly enriched in leukocytes. Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor. Using a mouse model of oxygen-induced retinopathy, p110δ inactivation was found to attenuate pathological retinal angiogenesis. p110δ inhibitors have been approved for use in human B-cell malignancies. Our data suggest that antagonizing p110δ constitutes a previously unappreciated therapeutic opportunity for diabetic retinopathy.

EGFL7 reduces CNS inflammation in mouse.

Extracellular matrix (ECM) proteins secreted by blood-brain barrier (BBB) endothelial cells (ECs) are implicated in cell trafficking. We discovered that the expression of ECM epidermal growth factor-like protein 7 (EGFL7) is increased in the CNS vasculature of patients with multiple sclerosis (MS), and in mice with experimental autoimmune encephalomyelitis (EAE). Perivascular CD4 T lymphocytes colocalize with ECM-bound EGFL7 in MS lesions. Human and mouse activated T cells upregulate EGFL7 ligand αvß3 integrin and can adhere to EGFL7 through integrin αvß3. EGFL7-knockout (KO) mice show earlier onset of EAE and increased brain and spinal cord parenchymal infiltration of T lymphocytes. Importantly, EC-restricted EGFL7-KO is associated with a similar EAE worsening. Finally, treatment with recombinant EGFL7 improves EAE, reduces MCAM expression, and tightens the BBB in mouse. Our data demonstrate that EGFL7 can limit CNS immune infiltration and may represent a novel therapeutic avenue in MS.

A Lipidomics Approach to Identifying Key Lipid Species Involved in VEGF-Inhibitor Mediated Attenuation of Bleomycin-Induced Pulmonary Fibrosis.

PURPOSE: Poor molecular characterization of idiopathic pulmonary fibrosis (IPF) has led to insufficient understanding of the pathogenesis of the disease, resulting in lack of effective therapies and poor prognosis. Particularly, the role of lipid imbalance due to impaired lipid metabolism in the pathogenesis of IPF has been poorly studied. EXPERIMENTAL DESIGN: The authors have used shotgun lipidomics in a bleomycin (BLM) mouse model of pulmonary fibrosis with vascular endothelial growth factor (VEGF)-inhibitor CBO-P11 as a therapeutic measure, to identify a comprehensive set of lipids that contribute to the pathogenesis of pulmonary fibrosis. RESULTS: The authors report that attenuation of BLM-induced fibrotic response with CBO-P11 cotreatment is accompanied by a decrease in total lipid content and specific downregulation of lipids, which are upregulated in response to BLM treatment. CONCLUSION AND CLINICAL RELEVANCE: Dysregulated lipids identified in this study hold the potential of being future biomarkers for IPF.

Dementia-like pathology in type-2 diabetes: A novel microRNA mechanism.

Although type-2 diabetes (T2D) has been reported to increase the risk of cognitive dysfunction and dementia, the underlying mechanisms remain unclear. Dementia-like pathology is attributed to the accumulation of cellular prion protein (PrPc) which plays a role in cognitive dysfunction. However, its involvement and regulation in diabetic dementia-like pathology is not well understood. Using T2D db/db (leptin receptor knockout) mice subjected to object recognition and Y-maze behavioral tests, we determined that short-term memory was compromised and that the mice displayed abrupt spontaneous behaviour compared to db/m control mice. MicroRNA analysis using qRT2-PCR array demonstrated a significant reduction in the transcript expression of microRNA-146a (miR-146a) in the brain of T2D db/db mice as compared to db/m controls. The sequence matching tools validated the binding of miR-146a to a conserved domain of the PrPc gene. Administration of mouse brain endothelial cell-derived exosomes (BECDEs) loaded with miR-146a into the brain's ventricle of T2D db/db mice attenuated brain PrPc levels and restored short-term memory function though not significant. Also, we observed hyperphosphorylation of tau through decreased expression of glycogen synthase kinase-3 in T2D db/db brains that regulates microtubule organization and memory function. We conclude that underexpression of miR-146a upregulates PrPc production in T2D db/db mice and the delivery of BECDEs loaded with a miR-146a can down regulate PrPc levels and restore short term memory function up to a certain extent.

A proteomics approach to identifying key protein targets involved in VEGF inhibitor mediated attenuation of bleomycin-induced pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a life expectancy of less than 5 years post diagnosis for most patients. Poor molecular characterization of IPF has led to insufficient understanding of the pathogenesis of the disease, resulting in lack of effective therapies. In this study, we have integrated a label-free LC-MS based approach with systems biology to identify signaling pathways and regulatory nodes within protein interaction networks that govern phenotypic changes that may lead to IPF. Ingenuity Pathway Analysis of proteins modulated in response to bleomycin treatment identified PI3K/Akt and Wnt signaling as the most significant profibrotic pathways. Similar analysis of proteins modulated in response to vascular endothelial growth factor (VEGF) inhibitor (CBO-P11) treatment identified natural killer cell signaling and PTEN signaling as the most significant antifibrotic pathways. Mechanistic/mammalian target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK) were identified to be key mediators of pro- and antifibrotic response, where bleomycin (BLM) treatment resulted in increased expression and VEGF inhibitor treatment attenuated expression of mTOR and ERK. Using a BLM mouse model of pulmonary fibrosis and VEGF inhibitor CBO-P11 as a therapeutic measure, we identified a comprehensive set of signaling pathways and proteins that contribute to the pathogenesis of pulmonary fibrosis that can be targeted for therapy against this fatal disease.

Evaluation of the potential therapeutic effects of a double-stranded RNA mimic complexed with polycations in an experimental mouse model of endometriosis.

OBJECTIVE: To assess the therapeutic potential of polyinosine-polycytidylic acid, a double-stranded RNA molecule with selective proapoptotic and antiangiogenic activity, complexed with polyethyleneimine (pIC(PEI)) in treating endometriosis. DESIGN: A heterologous mouse model of endometriosis was created by injecting human endometrial fragments into the peritoneum. Endometrial fragments were engineered to express the fluorescent protein mCherry as a reporter to monitor status over the course of the 4-week study. SETTING: University-affiliated infertility center. ANIMAL(S): Ovariectomized and hormone-replaced nude mice (n = 30) injected with fluorescent-labeled human endometrial fragments at 4-6 weeks of age. INTERVENTION(S): Animals (n = 10 per group) were injected with vehicle (control), the anti-VEGF compound CBO-P11 (0.6 mg/kg), or pIC(PEI) (0.6 mg/kg) twice weekly over the course of 4 weeks. MAIN OUTCOME MEASURE(S): Variations in the size of endometriotic implants were estimated by quantifying the expression of mCherry throughout the course of the experiment. Neovascularization, cellular proliferation, and apoptosis were estimated by quantitative immunofluorescence detection of PECAM, α-SMA, Ki67, and TUNEL. RESULT(S): pIC(PEI) promoted a significant increase in apoptosis and a decrease in neovascularization in human fragments, but did not reduce the size of endometriotic implants. CONCLUSION(S): While pIC(PEI) treatment had significant antiangiogenic and pro-apoptotic effects in this setting, longer periods of exposure than the ones supported by our heterologous model and/or assays in homologous mouse models of endometriosis may be necessary to detect an effect of this compound on lesion size.

Nitric oxide mediates bleomycin-induced angiogenesis and pulmonary fibrosis via regulation of VEGF.

Pulmonary fibrosis is a progressive lung disease hallmarked by increased fibroblast proliferation, amplified levels of extracellular matrix deposition and increased angiogenesis. Although dysregulation of angiogenic mediators has been implicated in pulmonary fibrosis, the specific rate-limiting angiogenic markers involved and their role in the progression of pulmonary fibrosis remains unclear. We demonstrate that bleomycin treatment induces angiogenesis, and inhibition of the central angiogenic mediator VEGF using anti-VEGF antibody CBO-P11 significantly attenuates bleomycin-induced pulmonary fibrosis in vivo. Bleomycin-induced nitric oxide (NO) was observed to be the key upstream regulator of VEGF via the PI3k/Akt pathway. VEGF regulated other important angiogenic proteins including PAI-1 and IL-8 in response to bleomycin exposure. Inhibition of NO and VEGF activity significantly mitigated bleomycin-induced angiogenic and fibrogenic responses. NO and VEGF are key mediators of bleomycin-induced pulmonary fibrosis, and could serve as important targets against this debilitating disease. Overall, our data suggests an important role for angiogenic mediators in the pathogenesis of bleomycin-induced pulmonary fibrosis.

The growth and aggressive behavior of human osteosarcoma is regulated by a CaMKII-controlled autocrine VEGF signaling mechanism.

Osteosarcoma (OS) is a hyperproliferative malignant tumor that requires a high vascular density to maintain its large volume. Vascular Endothelial Growth Factor (VEGF) plays a crucial role in angiogenesis and acts as a paracrine and autocrine agent affecting both endothelial and tumor cells. The alpha-Ca2+/Calmodulin kinase two (α-CaMKII) protein is an important regulator of OS growth. Here, we investigate the role of α-CaMKII-induced VEGF in the growth and tumorigenicity of OS. We show that the pharmacologic and genetic inhibition of α-CaMKII results in decreases in VEGF gene expression (50%) and protein secretion (55%), while α- CaMKII overexpression increases VEGF gene expression (250%) and protein secretion (1,200%). We show that aggressive OS cells (143B) express high levels of VEGF receptor 2 (VEGFR-2) and respond to exogenous VEGF (100nm) by increasing intracellular calcium (30%). This response is ameliorated by the VEGFR inhibitor CBO-P11, suggesting that secreted VEGF results in autocrine stimulated α-CaMKII activation. Furthermore, we show that VEGF and α-CaMKII inhibition decreases the transactivation of the HIF-1α and AP-1 reporter constructs. Additionally, chromatin immunoprecipitation assay shows significantly decreased binding of HIF-1α and AP-1 to their responsive elements in the VEGF promoter. These data suggest that α-CaMKII regulates VEGF transcription by controlling HIF-1α and AP-1 transcriptional activities. Finally, CBO-P11, KN-93 (CaMKII inhibitor) and combination therapy significantly reduced tumor burden in vivo. Our results suggest that VEGF-induced OS tumor growth is controlled by CaMKII and dual therapy by CaMKII and VEGF inhibitors could be a promising therapy against this devastating adolescent disease.

TNF-α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells.

AIM: To assess whether SIRT1 and VEGF are responsible for tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS)-induced angiogenesis and to examine the molecular mechanism(s) of action in human dental pulp cells (HDPCs). METHODOLOGY: Immortalized HDPCs obtained from Prof. Takashi Takata (Hiroshima University, Japan) were treated with LPS (1 µg mL(-1) ) and TNF-α (10 ng mL(-1) ) for 24 h. mRNA and protein levels were examined by RT-PCR and Western blotting, respectively. Migration and tube formation were examined in human umbilical vein endothelial cells (HUVECs). The data were analysed by one-way anova. Statistical analysis was performed at α = 0.05. RESULTS: LPS and TNF-α upregulated VEGF and SIRT1 mRNA and protein levels. Inhibition of SIRT1 activity by sirtinol and SIRT1 siRNA or inhibition of the VEGF receptor by CBO-P11 significantly attenuated LPS + TNF-α-stimulated MMPs production in HDPCs, as well as migration and tube formation in HUVECs (P < 0.05). Furthermore, sirtinol, SIRT1 siRNA and CBO-P11 attenuated phosphorylation of Akt, extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinase (JNK) and the nuclear translocation of NF-κB p65. Pre-treatment with inhibitors of p38, ERK, JNK, PI3K and NF-κB decreased LPS + TNF-α-induced VEGF and SIRT1 expression, MMPs activity in HDPCs and angiogenesis (P < 0.05) in HUVECs. CONCLUSIONS: TNF-α and LPS led to upregulation of VEGF and SIRT1, and subsequent upregulation of MMP-2 and MMP-9 production, and promote angiogenesis via pathways involving PI3K, p38, ERK, JNK and NF-κB. The results suggest that inhibition of SIRT1 and VEGF might attenuate pro-inflammatory mediator-induced pulpal disease.

Inhibitory effect of insulin-like growth factor-binding protein-7 (IGFBP7) on in vitro angiogenesis of vascular endothelial cells in the rat corpus luteum.

Angiogenesis in the developing corpus luteum (CL) is a prerequisite for establishment and maintenance of an early pregnancy. To explore the physiological significance of insulin-like growth factor-binding protein-7 (IGFBP7) in the developing CL, the effects of IGFBP7 on vascular endothelial growth factor (VEGFA)- and luteinizing hormone (LH)-induced in vitro tube formation were tested using isolated luteal microvascular endothelial cells (LECs). Capillary-like tube formation of LECs and their proliferation were stimulated by both VEGFA and LH. IGFBP7 treatment suppressed VEGFA- or LH-induced tube formation. The proliferation and migration of LECs, and phosphorylation of mitogen-activated protein kinase kinase and extracellular signal-regulated kinase 1/2 were inhibited by IGFBP7. Furthermore, IGFBP7 attenuated VEGFA-enhanced cyclooxygenase (COX)-2 mRNA expression and prostaglandin E2 secretion. These findings suggest the possibility that luteal IGFBP7 secretion may suppress the stimulatory effect of VEGFA on angiogenesis in the early CL.

Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays.

PURPOSE: To obtain human glioblastoma cells A172 expressing stem cell-related protein and comparison of radiosensitivity in these cells with X-rays and carbon beam. METHODS: Human monolayer-type A172 glioblastoma cells were maintained in normal medium with 10% bovine serum. In order to obtain sphere-type A172 cells the medium was replaced with serum-free medium supplemented with growth factors. Both types of A172 cells were irradiated with either X-rays or carbon ion beams and their radiosensitivity was evaluated. RESULTS: Serum-free medium induced expression of stem cell-related proteins in A172 cells along with the neurosphere-like appearance. These sphere-type cells were found resistant to both X-rays and carbon ion beams. Phosphorylation of histone H2A family member X persisted for a longer period in the cells exposed to carbon ion beams than in those exposed to X-rays and it disappeared quicker in the sphere type than in the monolayer type. Relative radioresistance of the sphere type cells was smaller for carbon ion beams than for X-rays. CONCLUSIONS: We demonstrated that glioblastoma A172 cells with induced stem cell-related proteins turned resistant to irradiation. Accelerated heavy ion particles may have advantage over X-rays in overcoming the tumor resistance due to cell stemness.

Matrix production and organization by endothelial colony forming cells in mechanically strained engineered tissue constructs.

AIMS: Tissue engineering is an innovative method to restore cardiovascular tissue function by implanting either an in vitro cultured tissue or a degradable, mechanically functional scaffold that gradually transforms into a living neo-tissue by recruiting tissue forming cells at the site of implantation. Circulating endothelial colony forming cells (ECFCs) are capable of differentiating into endothelial cells as well as a mesenchymal ECM-producing phenotype, undergoing Endothelial-to-Mesenchymal-transition (EndoMT). We investigated the potential of ECFCs to produce and organize ECM under the influence of static and cyclic mechanical strain, as well as stimulation with transforming growth factor ß1 (TGFß1). METHODS AND RESULTS: A fibrin-based 3D tissue model was used to simulate neo-tissue formation. Extracellular matrix organization was monitored using confocal laser-scanning microscopy. ECFCs produced collagen and also elastin, but did not form an organized matrix, except when cultured with TGFß1 under static strain. Here, collagen was aligned more parallel to the strain direction, similar to Human Vena Saphena Cell-seeded controls. Priming ECFC with TGFß1 before exposing them to strain led to more homogenous matrix production. CONCLUSIONS: Biochemical and mechanical cues can induce extracellular matrix formation by ECFCs in tissue models that mimic early tissue formation. Our findings suggest that priming with bioactives may be required to optimize neo-tissue development with ECFCs and has important consequences for the timing of stimuli applied to scaffold designs for both in vitro and in situ cardiovascular tissue engineering. The results obtained with ECFCs differ from those obtained with other cell sources, such as vena saphena-derived myofibroblasts, underlining the need for experimental models like ours to test novel cell sources for cardiovascular tissue engineering.

EGFL7 ligates αvß3 integrin to enhance vessel formation.

Angiogenesis, defined as blood vessel formation from a preexisting vasculature, is governed by multiple signal cascades including integrin receptors, in particular integrin αVß3. Here we identify the endothelial cell (EC)-secreted factor epidermal growth factor-like protein 7 (EGFL7) as a novel specific ligand of integrin αVß3, thus providing mechanistic insight into its proangiogenic actions in vitro and in vivo. Specifically, EGFL7 attaches to the extracellular matrix and by its interaction with integrin αVß3 increases the motility of EC, which allows EC to move on a sticky underground during vessel remodeling. We provide evidence that the deregulation of EGFL7 in zebrafish embryos leads to a severe integrin-dependent malformation of the caudal venous plexus, pointing toward the significance of EGFL7 in vessel development. In biopsy specimens of patients with neurologic diseases, vascular EGFL7 expression rose with increasing EC proliferation. Further, EGFL7 became upregulated in vessels of the stroke penumbra using a mouse model of reversible middle cerebral artery occlusion. Our data suggest that EGFL7 expression depends on the remodeling state of the existing vasculature rather than on the phenotype of neurologic disease analyzed. In sum, our work sheds a novel light on the molecular mechanism EGFL7 engages to govern physiological and pathological angiogenesis.

Cell-based delivery of glucagon-like peptide-1 using encapsulated mesenchymal stem cells.

Glucagon-like peptide-1 (GLP-1) CellBeads are cell-based implants for the sustained local delivery of bioactive factors. They consist of GLP-1 secreting mesenchymal stem cells encapsulated in a spherically shaped immuno-isolating alginate matrix. A highly standardized and reproducible encapsulation method is described for the manufacturing of homogeneous CellBeads. Viability and sustained secretion was shown for the recombinant GLP-1 and the cell endogenous bioactive factors like vascular endothelial growth factor, neurotrophin 3 (NT-3) and glial cell line-derived neurotrophic factor. Manufacturing and quality control is performed in compliance with good manufacturing practice and fulfils all regulatory requirements for human clinical use. GLP-1 CellBeads combine the neuro- and cardioprotective properties of both GLP-1 and mesenchymal stem cells. First promising results were obtained from preclinical studies and an ongoing safety trial in humans but further studies have to prove the overall potential of CellBead technology in cell-based regenerative medicine.