Neuroprotective effect of vascular endothelial growth factor / 中华实验眼科杂志

Vascular endothelial growth factor (VEGF),also known as vascular permeability factor,can promote the proliferation and migration of vascular endothelial cells,and enhance vascular permeability.In addition,VEGF family is also related to lymphatic vessel formation,inflammatory response,hematopoiesis and neuroprotective effect.Under the circumstances of ischemia,hypoxia and oxidative stress,VEGF can exert neuroprotective effect by increasing tissue perfusion,inhibiting cell apoptosis and stimulating neurogenesis.Therefore,therapeutic effect of VEGF in neurological diseases,such as neurodegenerative diseases and stroke has increasingly received considerable attention.On the other hand,anti-VEGF therapy for ocular pathologic neovascular diseases may lead to corresponding adverse effect.In this review,the mechanism of neuroprotective effect of VEGF and its roles in neurological diseases and ocular diseases were discussed.

Neuroprotective effect of vascular endothelial growth factor / 中华实验眼科杂志

Vascular endothelial growth factor(VEGF), also known as vascular permeability factor, can promote the proliferation and migration of vascular endothelial cells, and enhance vascular permeability.In addition, VEGF family is also related to lymphatic vessel formation, inflammatory response, hematopoiesis and neuroprotective effect.Under the circumstances of ischemia, hypoxia and oxidative stress, VEGF can exert neuroprotective effect by increasing tissue perfusion, inhibiting cell apoptosis and stimulating neurogenesis.Therefore, therapeutic effect of VEGF in neurological diseases, such as neurodegenerative diseases and stroke has increasingly received considerable attention.On the other hand, anti-VEGF therapy for ocular pathologic neovascular diseases may lead to corresponding adverse effect.In this review, the mechanism of neuroprotective effect of VEGF and its roles in neurological diseases and ocular diseases were discussed.

Histological changes secondary to use of anti-angiogenic therapy after interruption of vasa vasorum flow in the descending aorta: results in a porcine model / Alterações histológicas secundárias à interrupção dos vasa vasorum na aorta descendente com o uso de terapia antiangiogênica: resultados em modelo suíno

Background Anti-angiogenic regulators may have therapeutic implications for onset and progression of atherosclerosis. Objectives To demonstrate histological changes secondary to the use of bevacizumab in the aorta of pigs after interruption of flow in the vasa vasorum. Methods Twelve pigs were divided into two groups. The intercostal arteries of the descending aorta were dissected and ligated and wrapped with a polyvinyl chloride membrane. The treatment group received an intravenous dose of bevacizumab. After 15 days, the animals were euthanized and the aorta removed. Histological slides were prepared for control and treatment groups and for non-manipulated areas and analyzed for degree of angiogenesis, injury, inflammation, and intimal thickening. Data were expressed as mean (SD) of scores and groups were compared using the Mann-Whitney test. The Poisson distribution was used to calculate 95% confidence intervals for mean scores, in order to determine effect statistics. Results Bevacizumab had adverse effects on all treated pigs. The analysis using a Scale of Magnitudes for Effect Statistics showed a trend toward a decrease in angiogenesis [0.58 (1.79/-0.63)] and injury [0.55 (1.76/-0.66)] and an increase in inflammation [0.67 (1.89/-0.55)] with threshold moderate effects. There was no difference in intimal thickening [0 (1.19/-1.19)]. Conclusions The medication exhibited a trend toward reduced angiogenesis and injury, but no reduction in the inflammatory process or intimal thickening of the aortic wall. These findings are in disagreement with studies that correlate neovascularization with increased migration of inflammatory cells. Bevacizumab exhibited toxicity in the porcine model

Agentes antiangiogênicos podem ter implicações terapêuticas na progressão e manifestação da aterosclerose. Objetivos Demonstrar a alteração histológica secundária ao uso de bevacizumabe na aorta descendente de suínos submetida à interrupção dos vasa vasorum. Métodos Em doze suínos, divididos em dois grupos, foi realizada dissecção da aorta torácica, além de ligadura das artérias intercostais e proteção com polivinil. O grupo tratamento recebeu dose endovenosa de bevacizumabe. Após 15 dias, os animais foram sacrificados para retirada da artéria e preparo das lâminas histológicas dos grupos tratamento, controle e áreas não manipuladas para análise quanto aos graus de angiogênese, injúria, inflamação e espessamento intimal. A análise estatística foi conduzida através da média e do desvio padrão dos escores. As comparações entre os grupos foram realizadas pelo teste de Mann-Whitney. A distribuição de Poisson calculou os intervalos de confiança de 95% para as médias, a fim de determinar o efeito estatístico. Resultados O bevacizumabe causou efeitos adversos em todos os suínos tratados. As variáveis analisadas através da Escala de Magnitude para Efeito Estatístico demonstraram tendência de redução da angiogênese [0,58 (1,79/-0,63)] e da injúria [0,55 (1,76/-0,66)] e aumento da inflamação [0,67 (1,89/-0,55)] no limite do moderado. Não ocorreu diferença no espessamento intimal [0 (1,19/-1,19)]. Conclusões A medicação utilizada mostrou tendência de redução da angiogênese e da injúria, mas não reduziu o processo inflamatório ou o espessamento intimal da parede arterial. Esses achados contrariam estudos que correlacionam a neovascularização com o aumento da migração de células inflamatórias. O bevacizumabe mostrou toxicidade no modelo suíno

Leucine-rich G Protein-coupled Receptor-5 Is Significantly Increased in the Aqueous Humor of Human Eye with Proliferative Diabetic Retinopathy

Leucine-rich G protein-coupled receptor-5 (LGR5) is known to be a stem cell marker in many organs. LGR5 may have important roles in proliferative diabetic retinopathy (PDR) because LGR5 potentiate the Wnt/β-catenin pathway, which plays crucial roles in pathologic neovascularization in the retina. The association between LGR5 and retinal pathologic neovascularization has not yet been reported. In the present study, LGR5 was compared in human aqueous humor (AH) between normal control and patients with PDR to confirm the relationship between LGR5 and PDR. AH was collected from 7 naïve PDR patients and 3 control subjects before intravitreal injection and cataract surgery, respectively. LGR5 and key members of Wnt/β-catenin were assessed by western blotting. In the present study, it was confirmed for the first time that LGR5 is detected in AH and it increases in PDR patients. Key members of Wnt/β-catenin pathway were also increased in AH of PDR patients compared to control. These findings might support the hypothesis that LGR5 has important roles in PDR especially considering the roles of the Wnt/β-catenin pathway, which is activated by LGR5, contributing to retinal pathologic neovascularization.

Fotocoagulación panretinal y bevacizumab intravítreo en el tratamiento de la retinopatía diabética proliferativa activa / Panretinal photocoagulation and intravitreal bevacizumab in the treatment of active proliferative diabetic retinopathy

OBJETIVO: evaluar el efecto de la fotocoagulación panretinal e inyección intravítrea de bevacizumab sobre las áreas de neovascularización en pacientes con retinopatía diabética proliferativa activa. MÉTODOs: estudio experimental en 80 ojos de 62 pacientes con retinopatía diabética proliferativa con características de alto riesgo, a quienes se les asignó aleatoriamente fotocoagulación panretinal (Grupo L) o fotocoagulación panretinal con bevacizumab intravítreo (Grupo L + B). Variables: edad, sexo, color de la piel, tipo de diabetes mellitus, tiempo de evolución, tipo de tratamiento, área de difusión de fluoresceína y regresión de neovascularización retinal y/o del disco óptico. Se realizó un seguimiento de 9 meses. RESULTADOS: en la evaluación inicial el área media de difusión fue de 8,95 mm2 en el grupo L y de 10,08 mm2 en el grupo L + B (p = 0,347), que se modificó a 6,40 mm2 y 3,91 mm2 (p = 0,012) al mes; 3,15 mm2 y 1,02 mm2(p = 0,002) a los tres meses; 2,45 mm2 y 0,58 mm2 (p = 0,001) a los seis meses; 2,18 mm2 y 0,46 mm2 (p = 0,001) a los nueve meses, respectivamente. El análisis de las diferencias absolutas de los promedios mostró una reducción significativa de las áreas de difusión a favor del tratamiento combinado en comparación con el momento inicial. CONCLUSIONES: en pacientes con retinopatía diabética proliferativa activa el bevacizumab intravítreo combinado con fotocoagulación panretinal produjo regresión dramática de la neovascularización, permaneciendo estable desde el tercer mes al noveno.

OBJECTIVE: to evaluate the effect of panretinal photocoagulation and intravitreal injection of bevacizumab on neovascularization areas of patients with active proliferative diabetic retinopathy. METHODS: experimental study conducted in 80 eyes from 62 patients with proliferative diabetic retinopathy with high risk characteristics. These patients were randomly assigned to panretinal photocoagulation group (group L) or to the panretinal photocoagulation plus intravitreal bevacizumab group (group L + B). The studied variables were age, sex, race, type of diabetes mellitus, illness duration, type of treatment, fluorescein distribution area and retinal/optical disc neovascularization regression area. They were followed-up for 9 months. RESULTS: in the initial evaluation, the average diffusion area was 8,95 mm2 in group L and 10,08 mm2 in group L + B (p = 0,347), which changed to 6,40 mm2 and 3,91 mm2 (p = 0,012) respectively, after one month; 3,15 mm2 and 1,02 mm2 (p = 0,002) three months later, 2,45 mm2 and 0,58 mm2 (p = 0,001) after six months and 2,18 mm2 and 0,46 mm2 (p = 0,001) after nine months, respectively. The analysis of absolute differences of averages showed a significant reduction in the distribution areas of fluorescein that favored the combined therapy. CONCLUSIONS: in patients with active proliferative diabetic retinopathy, intravitreal bevacizumab combined with panretinal photocoagulation bring about dramatic regression of neovascularization, which remained stable from the third to the ninth month.

Mechanism of lung cancer angiogenesis: Recent advance / 第二军医大学学报

Angiogenesis is essential for tumor growth and metastasis, and it plays a key role in the development and progression of lung cancer. Angiogenesis is determined by the tumor microenvironment and regulated by multiple signaling pathways. Lung cancer angiogenesis process can be summarized as follows: (1) Continuing growth of tumor promotes the so-called "angiogenic switch" in the microenvironment, starting the angiogenic process: (2) Matrix metalloproteinases (MMPs) induce the degradation and remodeling of extracellular matrix (ECM): (3) Endothelial cells migrate through the remodeled ECMas induced by platelet-derived growth factor (PDGF) and chemokines: (4) In presence of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF), endothelial cells greatly proliferates: and (5) Lumen formation and vascular function are achieved by D114-Notch signaling. Currently, inhibition of angiogenesis has become an important option for lung cancer. Each stage of angiogenesis may become a potential target for treatment. New lights on the mechanisms of lung cancer angiogenesis is of great clinical significance for seaching effective anti-angiogenic and anti-lung cancer therapeutic.

Actividad angiogénica comparada de líquido cefalorraquídeo de pacientes con tumores primarios del sistema nervioso central / Compared angiogenic activity of cerebrospinal fluid of patients with primary central nervous system tumors

Introducción: Los tumores cerebrales continúan siendo una patología de mal pronóstico, lo que se refleja en la baja expectativa de vida de quienes los padecen. La angiogénesis es un proceso cardinal en el crecimiento tumoral y en la producción de metástasis. No obstante el conocimiento de los mecanismos subyacentes a la oncogénesis, las terapias continúan obteniendo resultados modestos. Está demostrado que el parénquima tumoral secreta factores que estimulan la cascada angiogénica. Sin embargo, no existen trabajos que evalúen el efecto angiogénico del líquido cefalorraquídeo (LCR). La hipótesis propuesta en este trabajo es que el LCR de los pacientes con tumores primarios del sistema nervioso central (SNC), posee en sí mismo propiedades angiogénicas. Material y Método: Estudio experimental preclínico. Se utilizó, en ciento ochenta huevos de gallina White Leghorn, el modelo de membrana alantocoriónica (MAC) de pollo. Estos huevos fueron incubados y sobre la membrana se implantaron filtros de metilcelulosa con líquidos cefalorraquídeos de pacientes con diferentes tumores cerebrales. Al grupo control se le adicionó suero fisiológico. Tras diez días de incubación se realizaron cortes histológicos de las muestras y se procedió al conteo de vasos sanguíneos en un microscopio con rejilla graduada. Resultados: Se demostró con significancia estadística (p<0,05) que existe efecto angiogénico en el LCR de pacientes con tumores primarios del SNC. Discusión: A partir de los resultados obtenidos, podemos proyectar futuros trabajos hacia nuevas terapias enfocadas en la angiogénesis diferencial. Los factores angiogénicos presentes en el LCR podrían constituir un nuevo blanco terapéutico contra los tumores cerebrales.

Introduction: Nowadays, brain tumors remains being a poor-prognosis pathology, which is reflected in the low life expectancy of the patients. The angiogenesis, is a fundamental process in the tumoral growing and the metastatic feasibility. In spite of knowing of the underlying mechanism of the oncogenesis, therapies still get poor results. It is demonstrated that tumoralparenchyma secretes factors that enhance the angiogenic cascade. However, any work has ever evaluated the angiogenic effect in the cerebrospinal fluid (CSF) itself. We hypothesize that CSF belonging of patients with primary central nervous system (CNS) brain tumors, presents angiogenic properties on their own. Material and Method: Preclinical experimental trial. In 180 eggs of White Legorn chicken it was used the chorioallantoic membrane (CAMA) assay. This eggs were incubated for tendays and over the membrane were implanted methylcellulose filters containing cerebrospinal fluid coming from patients affected by different brain tumors. The control group was instilledwith saline solution. It was performed different histological sections of the samples and then proceeded to the counting of the vessels in a microscope with a squared grille inside it. Results:We demonstrated with statistical significance (p<0.05) that CSF from primary brain tumor’s affected patients presents angiogenic effect. Discussion: Owing the presented results, we can plan future investigations targeting new therapies focused on the differential angiogenesis. The angiogenic factors in the CSF could represent a new therapeutic target against brain tumors.

Inhibitory effect of recombinant adenovirus expressing TEM8 gene against angiogenesis in mouse model of glioma / 第二军医大学学报

Objective: To evaluate the inhibitory effects of recombinant adenovirus carrying TEM8 (Ad-TEM8) against angiogenesis and growth of mouse glioma G422 cells in vitro and in vivo. Methods: The Ad-TEM8 was constructed and subcutaneously injected to immunize Kunming mice, and then the splenic lymphocytes were collected for co-culture with G422 cells in vitro. The growth inhibition of G422 cells was observed and IFN-γ secretion by the activated lymphocytes were examined by ELISOT method. In addition, the anti-tumor and anti-angiogenesis effects ofAd-TEM8 were observed in Kunming mice carrying G422 xeno grafts. Results: Ad-TEM8 effectively stimulated the generation of cytotoxic Tlymphocytes (CTLs)in Kunming mice and the secretion of IFN-γ. Subcutaneous injection of Ad-TEM8-induced cytotoxicity effectively inhibited in vivo tumor growth and angiogenesis. Conclusion: Ad-TEM8 can induce CTLs in mice, inhibit tumor growth in vitro and in vivo, and disrupt tumor vasculature. The anti-angiogenesis effect might be a mechanism for its in vivo anti-tumor effect; and TEM8 may serve as a novel target for anti-angiogenesis therapy of glioma.

Angiogenesis in the progression of cutaneous squamous cell carcinoma: an immunohistochemical study of endothelial markers

OBJECTIVE: To demonstrate the role of angiogenesis in the progression of cutaneous squamous cell carcinoma. INTRODUCTION: Angiogenesis is a pivotal phenomenon in carcinogenesis. Its time course in cutaneous squamous cell carcinoma has not yet been fully established. METHODS: We studied the vascular bed in 29 solar keratoses, 30 superficially invasive squamous cell carcinomas and 30 invasive squamous cell carcinomas. The Chalkley method was used to quantify the microvascular area by comparing panendothelial (CD34) with neoangiogenesis (CD105) immunohistochemical markers. The vascular bed from non-neoplastic adjacent skin was evaluated in 8 solar keratoses, 10 superficially invasive squamous cell carcinomas and 10 invasive squamous cell carcinomas. RESULTS: The microvascular area in CD105-stained specimens significantly increased in parallel with cutaneous squamous cell carcinoma progression. However, no differences between groups were found in CD34 sections. Solar keratosis, superficially invasive squamous cell carcinoma and invasive squamous cell carcinoma samples showed significant increases in microvascular area for both CD34- and CD105-stained specimens compared with the respective adjacent skin. DISCUSSION: The angiogenic switch occurs early in the development of cutaneous squamous cell carcinoma, and the rate of neovascularization is parallel to tumor progression. In contrast to panendothelial markers, CD105 use allows a dynamic evaluation of tumor angiogenesis. CONCLUSION: This study demonstrated the dependence of skin carcinogenesis on angiogenesis.

Anti-angiogenic Effect of Selective Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor(ZD1839) against Murine Renal Cell Carcinoma Orthotopic Model / 대한비뇨기과학회지

PURPOSE: ZD1839(IressaTM) is a selective epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKI) known to block the cell signaling pathway. However, the effect of ZD1839 in relation to renal cell carcinoma, which is highly angiogenic, has not been reported. Using an orthotopic model of murine renal cell carcinoma(Renca), we evaluated the inhibitory effect of ZD1839 on tumor growth and angiogenesis. MATERIALS AND METHODS: Renca cells (1x10(4)cells/10microliter) were first adsorbed in Gelfoam and were implanted into the balb/cj mouse kidney followed by obturation with the agarose bar. Then, tumor formation was assessed every week for 4 weeks. IC50 was obtained for ZD1839 and genistein in vitro. 7 days after the implantation, the mice were divided into three groups, and normal saline, ZD1839(40mg/kg/day), and genistein (80mg/kg/day) were subcutaneously injected for 14 days. 21 days after the implantation, the mice were sacrificed, and tumor volume measurement and analysis of microvessel density(MVD) were performed using the factor VIII-related antigen and vascular endothelial growth factor(VEGF). RESULTS: Renca tumors, which formed in the renal parenchyme and had a circular shape, reached the peak growth velocity between 14 and 21 days. MVD was the highest at 14 days of implantation. IC50 for ZD1839 and genistein were 4.68microM and 5.43microM, respectively. Tumor growth after the treatment with ZD1839 and genstein was inhibited by 86%(p<0.01) and 49%(p<0.05), respectively, compared to the control. MVD of ZD1839 and genistein-treated groups were 50%(p<0.01) and 29%(p<0.05) lower, respectively, and VEGF levels were 24%(p<0.05) and 27%(p<0.05) lower, respectively, compared to the control. CONCLUSIONS: This orthotopic implantation method of the Renca cell is an effective model for demonstrating the effect of an angiogenesis inhibitor. Our results suggest that the anti-angiogenesis effect of ZD1839 in the Renca orthotopic implantation model partially contributes to the tumor growth inhibition, and that ZD1839 may be more effective than genistein in the tumor growth regulation through the inhibition of angiogenesis.