Circulating ectosomes: Determination of angiogenic microRNAs in type 2 diabetes.

Ectosomes (Ects) are a subpopulation of extracellular vesicles formed by the process of plasma membrane shedding. In the present study, we profiled ectosome-specific microRNAs (miRNAs) in patients with type 2 diabetes mellitus (T2DM) and analyzed their pro- and anti-angiogenic potential. Methods: We used different approaches for detecting and enumerating Ects, including atomic force microscopy, cryogenic transmission electron microscopy, and nanoparticle tracking analysis. Furthermore, we used bioinformatics tools to analyze functional data obtained from specific miRNA enrichment signatures during angiogenesis and vasculature development. Results: Levels of miR-193b-3p, miR-199a-3p, miR-20a-3p, miR-26b-5p, miR-30b-5p, miR-30c-5p, miR-374a-5p, miR-409-3p, and miR-95-3p were significantly different between Ects obtained from patients with T2DM and those obtained from healthy controls. Conclusion: Our results showed differences in the abundance of pro- and anti-angiogenic miRNAs in Ects of patients with T2DM, and are suggestive of mechanisms underlying the development of vascular complications due to impaired angiogenesis in such patients.

Tumores neuroendocrinos: la era de las terapias dirigidas / Neuroendocrine tumors: the age of targeted therapies

Los tumores neuroendocrinos gastroenteropancreáticos (TNE-GEP) constituyen el segundo tumor avanzado más prevalente del tracto digestivo. En los últimos años, los recursos invertidos para la investigación en esta población de pacientes se han visto aumentados exponencialmente convirtiéndose en uno de los escenarios más atractivos para la investigación oncológica. Varias proteínas proangiogénicas han sido identificadas como sobreexpresadas en los TNE-GEP, incluyendo el factor de crecimiento del endotelio vascular y sus receptores, y las vías de señalización intracelular más relacionadas como la del receptor del factor de crecimiento epidérmico, el receptor tipo i del factor de crecimiento similar a la insulina y la vía de PI3K-(PTEN)-AKT-mTOR. Los resultados recientes de los 3 estudios fase iii más importantes en TNE-GEP han permitido la aprobación de 2 terapias dirigidas, sunitinib y everolimus, para el tratamiento de los pacientes con tumores neuroendocrinos pancreáticos después de décadas de mínimos avances en esta población (AU)

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are the second most prevalent group of advanced gastrointestinal tract tumors. Resources invested in research on this patient population have exponentially increased in recent years, and this has become one of the most attractive fields for oncological research. Several proangiogenic proteins have been found to be overexpressed in GEP-NETs, including vascular endothelial growth factor and its receptors and the more closely related intracellular signaling pathways such as the epidermal growth factor pathway, type I insulin-like growth factor receptor, and the PI3K-(PTEN)-AKTmTOR pathway. The recent results of the three most important Phase III studies in GEP-NET have allowed for approval of two targeted agents, sunitinib and everolimus, for the treatment of patients with pancreatic neuroendocrine tumors after decades of minimal advances in this population (AU)

Anti-angiogenic and anti-inflammatory effects of SERPINA3K on corneal injury.

SERPINA3K is a member of the serine proteinase inhibitor (SERPIN) family. Here we evaluated the therapeutic effects of SERPINA3K on neovascularization and inflammation in a rat cornea alkali burn model that is commonly employed to study corneal wounding. Topical treatment of the injured rat cornea with SERPINA3K (20 µg/eye/day) for 7 days significantly decreased the neovascular area, compared with the groups treated with BSA or PBS. The SERPINA3K treatment also ameliorated the corneal inflammation as evaluated by the inflammatory index. Furthermore, SERPINA3K enhanced the recovery of corneal epithelium after the alkali injury. Toward the mechanism of action, SERPINA3K down-regulated the expression of the pro-angiogenic and pro-inflammatory factors, vascular endothelial growth factor and tumor necrosis factor-α and up-regulated the expression of the anti-angiogenic factor, pigment epithelium-derived factor. SERPINA3K specifically inhibited growth of vascular endothelial cells. Meanwhile, SERPINA3K significantly up-regulated the expression of EGFR in the corneal epithelium. These findings suggest that SERPINA3K has therapeutic potential for corneal inflammation and NV.

An SPME-GC-MS method using an octadecyl silica fibre for the determination of the potential angiogenesis modulators 17beta-estradiol and 2-methoxyestradiol in culture media.

A simple and easily automable method based on solid-phase microextraction followed by gas chromatographic-mass spectrometric analysis was developed for the determination of two potential angiogenesis modulators 17beta-estradiol (17-BE) and 2-methoxyestradiol (2-MEOE) in culture media. Trifluoroacetic anhydride was used as the derivatising agent. A homemade octadecyl silica coating, characterised by a coating thickness of 72 +/- 10 microm and a good thermal stability until 250 degrees C, was prepared. Experimental design was used to optimise the extraction conditions in terms of derivatisation time, derivatisation temperature and time of extraction. As for method validation, lower limits of quantification of 0.17 and 0.015 microg/l for 17beta-estradiol and 2-methoxyestradiol, respectively, were obtained. Finally, the capabilities of the developed fibres were evaluated for the analysis of the investigated analytes developed by granulosa cells in culture media maintained under normoxic, hypoxic and anoxic conditions, in order to better elucidate their possible role in the angiogenic process. An increase of the production of both 17-BE and 2-MEOE in hypoxic and anoxic conditions seems to be related to the effect of oxygen deprivation.

Neoangiogenese na aterosclerose: modulacao por lipides nitrados / Neoangiogenesis in atherosclerosis: modulation through nitrated lipids

Lípides nitrados (NO₂-FA) são apontados como uma nova classe de mediadores lipídicos, podendo atuar como reservatórios endógenos de Oxido nítrico (^.NO) bem como moduladores pluripotentes de sinalização celular. Recentemente, tem sido sugerido que os doadores de ^.NO estariam envolvidos na regulação da angiogênese. Evidências contundentes indicam ainda que o processo de neovascularização poderia contribuir para a patogênese de uma serie de condições clínicas, entre elas a aterosclerose. Contudo, apesar de diversos estudos terem explorado os efeitos biológicos dos NO₂-FA, os efeitos destes compostos sobre o processo de angiogênese não haviam sido descritos. Dessa maneira, o presente trabalho investigou os efeitos dos NO₂-FA (derivados da nitração do acido linoléico e oléico) no processo de angiogênese. Demonstrou-se que os NO₂-FA podem atuar como mediadores pro-angiogênicos. Este efeito foi caracterizado em células endoteliais humanas, assim como, em modelos ex vivo e in vivo. Nas células endoteliais, observou-se que os NO₂-FA não influenciaram a proliferação ou a viabilidade celular, ao passo que estimularam a migração. Demonstrou-se também que os NO₂-FA podem modular o brotamento ex vivo de novos vasos, em cultura de anéis de aorta de rato, bem como o processo angiogênico in vivo observado na membrana corioalantóica de embrião de galinha. Adicionalmente, os NO₂-FA induziram a expressão do fator de crescimento endotelial vascular (VEGF), que é o principal mediador do processo de angiogênese. Em relação ao mecanismo de ação, os achados sugerem que os efeitos demonstrados seriam via mecanismos dependentes de ^.NO, uma vez que foram abolidos na presença de um seqüestrador de ^.NO, enquanto concentrações equivalentes dos Lípides precursores não demonstraram qualquer influência nas condições experimentais utilizadas neste estudo...

Nitrated lipids ( NO₂-FA) are described as a new class of lipid mediators that are able to act as endogenously nitric oxide ( ^.NO) reservoirs as well as pluripotent cell signaling modulators. Furthermore, recent findings suggest that ^.NO donors could be involved in the regulation of angiogenesis. Compelling evidence also indicate that the neovascularization process might contribute to the pathogenesis of many clinical conditions, such as atherosclerosis. However, although several studies have explored the NO₂-FA biological properties, the effects of these compounds on the angiogenic process remain unknown. Hence, the present study investigated the effects of the NO₂-FA (derivates from the nitration of linoleic and oleic acids at physiological concentrations) on angiogenesis process. It is demonstrated that the NO2-FA could act as pro-angiogenic mediators. This effect was observed not only in human endothelial cells but also in ex vivo and in vivo models. Using endothelial cells, it is showed that NO₂-FA failed to affect cell proliferation or influence cellular viability, but significantly stimulated cell migration. It was also found that the NO₂-FA might modulate the ex vivo sprouting of new vessels as well as the in vivo angiogenic process, while inducing the expression of the vascular endothelial growth factor, the main mediator of angiogenesis. The data are consistent with the hypothesis that the observed effects mediated by NO-dependent mechanisms, since the presence of a ^.NO scavenger abrogated the induced effects, whereas equimolar concentrations of its precursors, showed no effect on angiogenesis under our experimental conditions. Finally, the pro-angiogenic effects of NO2-FA were mediated by the stabilization of the hypoxia inducible factor-l1á (HIF-1á) protein, because these compounds increased the protein amount and failed to show inductive effects...

Current methods for assaying angiogenesis in vitro and in vivo.

Angiogenesis, the development of new blood vessels from an existing vasculature, is essential in normal developmental processes and in numerous pathologies, including diabetic retinopathy, psoriasis and tumour growth and metastases. One of the problems faced by angiogenesis researchers has been the difficulty of finding suitable methods for assessing the effects of regulators of the angiogenic response. The ideal assay would be reliable, technically straightforward, easily quantifiable and, most importantly, physiologically relevant. Here, we review the advantages and limitations of the principal assays in use, including those for the proliferation, migration and differentiation of endothelial cells in vitro, vessel outgrowth from organ cultures and in vivo assays such as sponge implantation, corneal, chamber, zebrafish, chick chorioallantoic membrane (CAM) and tumour angiogenesis models.