ABSTRACT
Objective Todetectthe level of plasma VEGF before and after treatment of arteriovenous mal-formationpatients,and the pathophysiological role of VEGF in arteriovenous malformationpatientswas also studied. Methods The blood samples of 17 arteriovenous malformation patients were collected according to the following three groups:group before operation(AVM),group 24 hours after operation(AVM24h)and group 30 days after operation(AVM30d).As a control(Con),22 blood samples were collected from lumbar laminectomypatients.The level of plasma VEGF was determined by ELISA assay. Results Compared with the control group,the plasma VEGF was significantly decreased in AVM group and AVM24h group(P < 0.05),while the plasma VEGF in AVM30d groupwas similarto that of the control group. Conclusions Abnormal blood vessel plays an important pathophysiological role in cerebral arteriovenous malformation,and the metabolism of VEGF is involved in the pro-cess of arteriovenous malformation.
ABSTRACT
La participación de los factores antiangiogénicos, la forma soluble de la fms-semejante a la tirosina quinasa (Flt-1s) y la endoglina soluble (Engs), en el desarrollo de la preeclampsia (PE) se ha demostrado en múltiples estudios clínicos y experimentales. Estos estudios están complementados por estudios en animales, en los cuales la sobreexpresión de estos factores antiangiogénicos origina manifestaciones clínicas muy similares a la PE. El origen de esta enfermedad permanece desconocido. Sin embargo, factores genéticos, ambientales e inmunológicos parecen alterar el desarrollo normal de la placenta, lo cual conduce últimamente a la PE. Flt-1s y Engs inhiben la producción y las propiedades proangiogénicas del factor de crecimiento vascular endotelial (FCVE) y del factor de crecimiento placentario (FCP), necesarios para el desarrollo normal vascular de la placenta y las adaptaciones vasculares fisiológicas del embarazo. Cantidades exageradas de Flt-1s y Engs se producen en la placenta disfuncional y se liberan en la circulación materna. Altas concentraciones de Flt-1s y Engs se encuentran en la circulación materna semanas antes de que la enfermedad sea detectada clínicamente. Las capacidades de los factores angiogénicos para predecir PE en embarazos asintomáticos de riesgo bajo y alto son inconsistentes y no útiles para el uso clínico. Por otro lado, proporciones de los factores Flt-1s/FCP, FCP/Flt-1s, y FCP/Eng poseen valores predictivos más altos para diagnosticar PE y predecir sus complicaciones en mujeres con sintomatología de PE. En estas condiciones, el uso clínico de estos marcadores biológicos podría ser implementado en un futuro cercano. Las propiedades biológicas y farmacocinéticas de las estatinas las convierten en uno de los medicamentos con más potencial preventivo para la PE. Otros opciones terapéuticas que se están estudiando son medicamentos que directamente inhiban los factores antiangiogénicos circulantes. Estudios in vitro y estudios pilotos clínicos se están realizando actualmente examinando la seguridad materno-fetal, la transferencia placentaria y la efectividad de estas terapias.
The role of the antiangiogenic factors, the soluble form of the fms-like tyrosine kinase receptor 1 (sFlt1) and the soluble endoglin (sEng), in the development of preeclampsia (PE) has been demonstrated in multiple clinical and experimental studies. These studies are complemented by animal studies, in which overexpression of these antiangiogenic factors leads to clinical manifestations similar to PE. Although, the origin of this disease remains unknown, genetic, environmental, and immunological factors appear to affect the normal placental development, resulting ultimately in PE. sFlt-1 and sEng inhibit the proangiogenic properties of the vascular endothelial growth factor (VEGF) and the placental growth factor (PlGF), affecting the normal vascular development in the placenta and the physiological vascular adaptations that occur in pregnancy. Exaggerated amounts of sFlt-1 and sEng, produced in the dysfunctional placenta, are released into the maternal circulation and elevated circulating concentrations of these antiangiogenic factors are found several weeks prior to the clinical manifestations of the disease. Multiple studies have reported the capacity of circulating antiangiogenic factor concentrations to predict PE in asymptomatic low and high risk pregnancies. The reported predictive values of sFlt-1 and sEng are inconsistent across these studies and therefore their clinical use in this population is not recommended. On the other hand, maternal plasma concentrations of these factors appear to have a better performance in women with symptoms of PE. Among the possible combinations, the ratios of sFlt-1/PlGF, PlGF/sFlt-1, and PlGF/Engs seem to have the highest sensitivities and specificities to diagnose PE as well as the highest predictive values for PE-related adverse outcomes. These properties support their clinical use in this setting and it is likely those ancillary tests will be incorporated to the clinical practice in the near future. The participation of antiangiogenic factors in the pathogenesis of PE, also have stimulated investigation of new targeted therapies. The biological and pharmacokinetic properties of statins have converted them in one of the most promising preventive therapies for this disease. Others are investigating agents that directly inhibit the circulating antiangiogenic factors. In-vitro and pilot clinical studies are currently evaluating the effectiveness, maternal-fetal safety, and placental transference of these therapies.
ABSTRACT
Background Retinal Muller cells participate in the pathological process of diabetic retinopathy (DR) through expressing vascular endothelial growth factor (VEGF).It is reported that FK506 inhibits the expression of VEGF in solid tumors and experimental corneal neovascularization,but whether FK506 exerts its role on retinal Müller cells or not is still unclear.Objective This study aimed to investigate how FK506 affects the expression vascular endothelial growth factor (VEGF) in rat retinal Müller cells under the condition of high glucose.Methods Immortalized rat retinal Müller cell line was regularly cultivated and logarithmic phase of cells were incubated in 96-well plate with the cell density of 1 × 104/ml.Different concentrations of FK506 (800.00,400.00,200.00,100.00,75.00,50.00,25.00,12.50 and 6.25 pg/ml) (100 μl/well) were added into the culture medium to determine the half maximal inhibitory concentration (IC50) of FK506 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT).The cell lines were cultured with DMEM medium (containing D-glucose of 5.5 mmol/L) or high glucose DMEM (containing D-glucose of 50 mmol/L),and 75 pg/ml FK506 were added into DMEM,respectively,and the cells were divided into the normal control group,FK506 group,high glucose culture group and high glucose + FK506 group.ELISA was employed to assay the content of VEGF protein in the cell supernatant.The expressions of VEGF mRNA and protein in the cells were detected by reverse transcription PCR (RT-PCR) and Western blot,respectively.Results The cells grew well in the normal control group,FK506 group,high glucose culture group and high glucose+FK506 group in 12,24 and 48 hours after culture with the polygon-like shape.The IC50 of FK506 was 75 pg/ml.The contents of FK506 in the cell supernatant were (966.46± 13.59) pg/ml,(1 059.42±67.43) pg/ml,(16 243.11 ±3 926.38) pg/ml and (9 467.25± 1 525.56) pg/ml in the normal control group,FK506 group,high glucose culture group and high glucose+FK506 group,respectively,showing a significant difference among the four groups (F =20.51,P =0.00).The VEGF levels in cell supernatant were significantly higher in the high glucose group than those of the normal group and the high FK506 group (P =0.00,P =0.02),but no significant difference was found in the VEGF level in cell supernatant between the control group and FK506 group (P =0.08).The expressions of VEGF mRNA and protein in the cells were significantly different among the four groups (F=126.06,P=0.00;F=5.44,P=0.01),and the relative expressing values of VEGF mRNA and protein in the cells of the high glucose group were significantly higher than those of the control group and the high+ FK506 group (all at P＜0.01).The relative expressing values of VEGF mRNA and protein were 0.64±0.09 and 0.68±0.18 in the FK506 group,which were lower than those of the normal control group (0.84±0.07 and 0.75± 0.03).However,no significant differences were seen between the two groups (P =0.05,0.07).Conclusions The expression of VEGF in rat retinal Müller cells up-regulates under the high glucose condition.FK506 plays inhibitory effects on VEGF expression to certain extent in vitro.