Streptozotocin-induced diabetic retinopathy in mice: Model establishment and evaluation / 第二军医大学学报

Objective: To establish streptozotocin (STZ)-induced diabetic retinopathy model in mice, and to observe the pathological changes of the retina in early diabetic stages and the expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR)1 and VEGFR2 in the mouse model. Methods: C57BL/6J mice, aged 6-8 weeks, received intraperitoneal injection of STZ (55 mg/kg) once a day for 5 d. The fasting blood glucose concentration was measured 1 week after injection. The diabetic and control mice were fed for 5 months. Then the morphological changes of retina in diabetic mice were analyzed by H-E staining, Evans blue perfusion angiography and retinal vascular network digestion. The expression of VEGF and its receptors VEGFR1, VEGFR2 in diabetic retinopathy was analyzed by quantitative real-time PCR and Western blotting. Results: Compared with the control group, the blood glucose levels of the model group were significanlty increased 1 week, 1 to 5 months after injection (all higher than 16.5 mmol/L, all P<0.01). At 5 months after injection, the whole retina of the model group became thinner; the number of photoreceptor cells, inner and outer nuclear cells were decreased and disorderly arranged; the blood vessels went tortuously with leakage and leakage spots; the number of vascular endothelial cells was increased, with altered morphology; the number of peripheral cells was decreased; and there were no cellular capillaries and lumen occlusion. The expression levels of VEGF, VEGFR1 and VEGFR2 protein and mRNA were significantly increased in the model group compared with the control group (all P < 0.01). Conclusion: Diabetic retinopathy mouse model has been successfully constructed, with proliferative diabetic retinopathy appearing 5 months after diabetes, and the expression levels of VEGF, VEGFR1 and VEGFR2 are increased in the retina of diabetic mice.

Fatores de risco associados à intervenção com injeção intravítrea de anti-VEGF em pacientes com edema macular diabético / Risk factors related to the intervention with intravitreal anti-VEGF injection in patients with diabetic macular edema

Resumo Objetivo: Propor um modelo de regressão logística para auxiliar na decisão de realização da injeção intravítrea (IIV) de anti-VEGF, a partir da quantificação e hierarquização dos fatores de risco que compõem o perfil dos indivíduos diabéticos. Métodos: Trata-se de estudo transversal, observacional e inferencial, realizado em três instituições da Paraíba, de julho de 2015 a setembro de 2016. O modelo de regressão logística foi utilizado para obtenção do modelo preditivo e os dados foram analisados no software R®. Resultados: Foram avaliados 80 pacientes com diabetes tipo 1 ou 2, maiores de 18 anos, dos quais 57,5% não tiveram indicação de IIV e 42,5% receberam indicação deste tratamento. No grupo com edema macular diabético (EMD), a média de idade foi de 60,65 anos, sendo 52,94% do sexo feminino. Ainda nesse grupo, a maioria apresentou retinopatia diabética não-proliferativa severa ou retinopatia proliferativa (79,41%). Foram identificados como fatores de risco para EMD: o indivíduo ser aposentado (OR=5,22; p-valor 0,05), ter histórico pessoal de retinopatia diabética (OR=20,27; p-valor 0,006) e de tratamento prévio com anti-VEGF (OR=23,23; p-valor 0,002). Conclusão: Os resultados da pesquisa evidenciaram que um indivíduo diabético com baixa visual e apresentando esses três fatores deve ser encaminhado o quanto antes ao especialista, pois possui, com 91,17% de acerto, risco de apresentar EMD com necessidade de IIV de anti-VEGF. Essa ferramenta pode servir como coadjuvante na tomada de decisão, sobretudo do não-retinólogo, a fim de encaminhar para diagnóstico e tratamento precoces os indivíduos com EMD, o que pode ser decisivo na prevenção da perda visual irreversível nesses pacientes.

Abstract Purpose: To propose a predictive model to aid in the decision to perform the intravitreal anti-VEGF injection, based on the risk factors quantification and hierarchy presented by diabetic patients. Methods: It is a cross-sectional, observational and inferential study carried out in three institutions in Paraíba from July 2015 to September 2016. The logistic regression model was used to obtain the predictive model and data were analyzed in R(r) software. Results: Eighty patients with type 1 or 2 diabetes, over 18 years of age, were included, 57.5% of whom had no indication of IIV and 42.5% received an indication of this treatment. In the group with diabetic macular edema (DME), the mean age was 60.65 years, of which 52.94% were female. In this group, the majority presented severe non-proliferative diabetic retinopathy or proliferative retinopathy (79.41%). The main risk factors for DME were: be retired (OR = 5.22, p-value0.05), had a personal history of diabetic retinopathy (OR = 20.27, p-value 0.006), and previous treatment with anti-VEGF (OR = 23.23, p-value 0.002). Conclusion: The results of the research showed that a diabetic patient with low visual acuity and presenting these three factors should be referred as soon as possible to the specialist, since he presents a risk of presenting DME with need for anti-VEGF IIV, with 91.17% of accuracy. This tool can serve as an adjunct to decision making, especially the nonretinologist, in order to refer individuals with EMD to early diagnosis and treatment, which may be crucial in preventing irreversible visual loss in these patients.

Effects of Acupuncture-rehabilitation Therapy on Neurological Function and Expression of Vascular Endothelial Growth Factor Receptors, Flt-1 and Flk-1, after Focal Cerebral Ischemia in Rats / 中国康复理论与实践

Objective To explore the effect of acupuncture-rehabilitation therapy on neurological function and expression of Flt-1 and Flk-1, members of vascular endothelial growth factor receptors, after permanent focal cerebral ischemia in rats. Methods Ninety male Sprague-Dawley rats were divided into five groups, namely sham group, model group, acupuncture group, rehabilitation group and acupunc-ture-rehabilitation group, and each group was further divided into 3-day, 7-day and 14-day subgroups, equally. Their middle cerebral arteries were occluded except those of sham group. The sham and model groups accepted no treatment, while the acupuncture group accepted clus-ter needling of scalp acupuncture, the rehabilitation group accepted treadmill training, and the acupuncture-rehabilitation group accepted both acupuncture and treadmill training. They were assessed with modified Neurologic Severity Score (mNSS) 3, 7 and 14 days after model-ing, while the expression of Flt-1 and Flk-1 were determined with Western blotting. Results The mNSS score reduced in all the treatment groups (P<0.05) compared with that of the model group at every time point, and was the least in the acupuncture-rehabilitation group (P<0.05) 7 and 14 days after modeling among the treatment groups. Meanwhile, the expression of Flt-1 and Flk-1 protein increased in all the treatment groups (P<0.05), and was the most in the acupuncture-rehabilitation group (P<0.05). Conclusion Acupuncture-rehabilitation thera-py can promote the neurological function recovery in rat with permanent focal cerebral ischemia, which may be associated with the continu-ous inducement of Flt-1, Flk-1 protein expression in ischemic penumbra cortex.

Pivotal role of vascular endothelial growth factor pathway in tumor angiogenesis

The shaping of new blood vessels is a significant event in cancer growth and metastasis. Therefore, the molecular system of cancer angiogenesis has garnered considerable interest in cancer research. The vascular endothelial growth factor (VEGF) and VEGF receptor pathway are recognized as the key regulators of the angiogenic process. Activation of the VEGF/VEGF-receptor pathway initiates signaling cascades that promote endothelial cell growth, migration, and differentiation. Recently, VEGF was shown to play a role in the recruitment of bone marrow-derived endothelial progenitor cells to neovascularization sites. The role of VEGF in promoting tumor angiogenesis and the occurrence of human cancers has led to the rational design and development of agents that selectively target this pathway. Moreover, these anti-VEGF/VEGF receptor agents show therapeutic potential by inhibition of angiogenesis and tumor growth in preclinical models. In this review, we summarize the role of the VEGF pathway during tumor angiogenesis.

Influence of vascular endothelial growth factor inhibition on simple renal cysts in patients receiving bevacizumab-based chemotherapy

PURPOSE: Although angiogenesis has been implicated in the promotion of renal cyst growth in autosomal dominant polycystic kidney disease, no studies have investigated the role of angiogenesis in the growth of simple renal cysts. The aim of current study was to investigate the effect of chemotherapy with the antivascular endothelial growth factor antibody bevacizumab on renal cyst development and growth in cancer patients. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 136 patients with a variety of cancers that were treated with bevacizumab-based chemotherapy for metastatic disease. The presence of and changes in renal cysts were evaluated by retrospective analysis of computed tomography scans performed for assessment of tumor response to bevacizumab-based therapy. RESULTS: The median age of the patients was 64 years. Renal cysts were identified in 66 patients, in whom 33 (50%) had a single cyst and the rest had 2 or more cysts. The average dose of bevacizumab was 2.68 mg/kg per week. Median duration of treatment was 33 weeks. Average cyst size was 1.9±2.4 cm at the beginning of the study and the majority of the cysts (54 patients, 84%) did not change in size or shape during bevacizumab treatment. No patients were identified with new cysts. Cyst size changed in 10 patients (16%): an increase of 15% to 40% from the baseline size in 5 patients and a decrease in size of 10% to 70% in another 5 patients. The duration of bevacizumab therapy was significantly longer in the subgroup of patients with diminished or increased cyst size than in the patients with stable cyst size: 62 weeks versus 29 weeks, respectively (p=0.0002). CONCLUSIONS: Our data demonstrated that simple renal cysts were stable in size and number in the vast majority of cancer patients treated with bevacizumab.

Insulin promotes rhesus retinal vascular endothelial cells angiogenesis via VEGF-A/VEGFR2 pathway / 中华内分泌代谢杂志

Rhesus retinal vascular endothelial cell line RF/6A cells were treated with human insulin. Cell proliferation, migration, and lumen formation, as well as the expressions of vascular endothelial growth factor-A ( VEGF-A ), VEGF-A receptors, and phosphorylated receptors were measured. Insulin promoted RF/6A cell proliferation, migration, and lumen formation ( all P＜0. 01 ). Insulin increased the expression of VEGF-A mRNA and improved its protein activity ( all P＜0. 05 ), and promoted the expression of VEGFR2 mRNA and its phosphorylation ( both P＜0. 01 ). There was no significant difference in the expression of VEGFR1 mRNA among the groups ( P＞0. 05 ).

TLR4 signaling promotes secretion of VEGF/IL-8 in prostate cancer PC3 cells and related mechanism / 第二军医大学学报

Objective: To study TLR4 expression in human prostate cancer PC3 cells and the related intracellular signaling mechanisms. Methods: Human prostate cancer PC3 cells were stimulated with TLR4-specific ligand lipopolysaccharide (LPS), then the cells and supernatants were collected 0, 2, 6, 12, 24, and 48 hours after LPS stimulation. TLR4 mRNA and protein expression was examined by reverse transcription-PCR and Western blotting analysis, respectively. The mRNA expression of TGF-β, VEGF, 1L-8, COX-2, and MMP3 was also measured by reverse transcription-PCR, and the levels of VEGF, IL-8 in the supernatants were examined by ELISA. To further study the related signaling pathway, MAPK and NF-κB signaling pathways were blocked by specific inhibitors in PC3 cells before LPS stimulations the cells were collected after 4 hours and the supernatants were collected after 24 hours; and the above mentioned factors were examined by reverse transcription-PCR and ELISA again. Results: TLR4 expression was up-regulated by LPS stimulation in human prostate cancer PC3 cells, which significantly increased mRNA expression of TGF-β, VEGF, IL-8, COX-2, and MMP3 and secretion of VEGF and IL-8 in the supernatants (P<0.05); further study showed that p38 MAPK and NF-κB signal pathways were involved in the process. Conclusion: TLR4 signaling promotes VEGF and IL-8 secretion through p38 MAPK and NF-κB signal pathways.

Expression of vascular endothelial growth factor and its receptors in the distracted periosteum after mandibular distraction osteogenesis