Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin.

Opticin is an endogenous vitreous glycoprotein that may have therapeutic potential as it has been shown that supranormal concentrations suppress preretinal neovascularization. Herein we investigated the pharmacokinetics of opticin following intravitreal injection in rabbits. To measure simultaneously concentrations of human and rabbit opticin, a selected reaction monitoring mass spectrometry assay was developed. The mean concentration of endogenous rabbit opticin in 7 uninjected eyes was measured and found to be 19.2 nM or 0.62 µg/mL. When the vitreous was separated by centrifugation into a supernatant and collagen-containing pellet, 94% of the rabbit opticin was in the supernatant. Intravitreal injection of human opticin (40 µg) into both eyes of rabbits was followed by enucleation at 5, 24, and 72 h and 7, 14, and 28 days postinjection (n = 6 at each time point) and measurement of vitreous human and rabbit opticin concentrations in the supernatant and collagen-containing pellet following centrifugation. The volume of distribution of human opticin was calculated to be 3.31 mL, and the vitreous half-life was 4.2 days. Assuming that rabbit and human opticin are cleared from rabbit vitreous at the same rate, opticin is secreted into the vitreous at a rate of 0.14 µg/day. We conclude that intravitreally injected opticin has a vitreous half-life that is similar to currently available antiangiogenic therapeutics. While opticin was first identified bound to vitreous collagen fibrils, here we demonstrate that >90% of endogenous opticin is not bound to collagen. Endogenous opticin is secreted by the nonpigmented ciliary epithelium into the rabbit vitreous at a remarkably high rate, and the turnover in vitreous is approximately 15% per day.

Estudio del riesgo cardiovascular en pacientes con bloqueo del sistema renina-angiotensina a través del proteoma de las vesículas extracelulares circulantes / Cardiovascular risk study in patients with renin-angiotensin system blockade by means of the proteone of circulating extracellular vesicles

Introducción: Las vesículas extracelulares (EV) son liberadas al torrente circulatorio por determinados tipos celulares a consecuencia de procesos de transporte, activación o muerte celular. El recuento de EV circulantes de origen plaquetario y endotelial ha demostrado tener un importante papel como biomarcador de riesgo cardiovascular. Por lo tanto, el proteoma de estas EV podría reflejar los procesos celulares subyacentes en pacientes con hipertensión arterial y albuminuria. Material y métodos: El contenido proteico de las EV circulantes se ha analizado mediante cromatografía líquida acoplada a espectrometría de masas. Las EV han sido aisladas mediante un protocolo de ultracentrifugación optimizado para evitar la contaminación de proteínas del plasma. La pureza de la fracción aislada ha sido verificada mediante microscopia electrónica y confocal, y por citometría de flujo. Resultados: En este estudio mostramos un método de gran rendimiento y pureza para obtener extractos proteicos de EV circulantes de pacientes hipertensos con/sin albuminuria para análisis proteómico. Además, aportamos el proteoma de referencia de EV de estos pacientes, compuesto por 2.463 proteínas, y demostramos que las proteínas transportadas por estas vesículas están relacionadas con procesos cruciales involucrados en el riesgo cardiovascular asociado. Conclusión: El proteoma de las EV circulantes constituye una interesante fuente de indicadores para la evaluación de procesos relacionados con el riesgo cardiovascular en pacientes hipertensos con bloqueo del sistema renina-angiotensina

Introduction: Extracellular vesicles (EVs) are released to the bloodstream by certain cell types due to transport, activation and cell death processes. Blood count of EVs from platelet and endothelial origin has been proved to be a cardiovascular risk biomarker. Thus, EVs proteome might reflect the underlying cellular processes in hypertensive patients with albuminuria. Material and methods: Protein content of circulating EVs was analyzed by liquid chromatography coupled to mass spectrometry. EVs were isolated by an ultracentrifugation protocol optimized in order to avoid contamination by blood plasma proteins. Purity of the isolated fraction was verified by electronic and confocal microscopy, and by flow cytometry. Results: We hereby show a method to isolate circulating EVs from hypertensive patients with/without albuminuria with high yield and purity. Besides, we provide a reference proteome of the EVs of these patients, composed of 2,463 proteins, and prove that the proteins carried by these vesicles are associated with crucial processes involved in the inherent cardiovascular risk. Conclusion: The proteome of circulating EVs is an interesting source of indicators in the evaluation of cardiovascular risk in hypertensive patients with renin-angiotensin system blockage

Artificial biomimicking matrix modifications of nanofibrous scaffolds by hE-cadherin-Fc fusion protein to promote human mesenchymal stem cells adhesion and proliferation.

Extracellular matrix (ECM) plays a fundamental role in regulating cell attachment, proliferation, migration and differentiation. Both synthetic and biologically derived materials have been explored as an ECM in regenerative medicine and tissue engineering. To biomimick the extracellular matrix, we combined the advantages of the biological properties of nanofibrous scaffolds and the fusion protein to apply for the culture of human mesenchymal stem cells in vitro. In this study, we fabricated well random-oriented/aligned nanofibrous scaffolds with PCL, modified with hE-cadherin-Fc fusion protein and studied the synergistic effect of the scaffolds. The random-oriented/aligned architecture was observed in the nanofibrous scaffolds by SEM. XPS and WCA measurements evidenced that hE-cadherin-Fc was successfully modified on the PCL nanofibrous scaffolds and hydrophilicity of the scaffolds was well improved after fusion protein coating. The hE-cadherin-Fc modified markedly promoted the adhesion and proliferation of hMSCs and guided hMSCs to a spindlier morphology compared with unmodified nanofibrous scaffolds. Furthermore, hMSCs on the hE-cadherin-Fc-coated nanofibrous scaffolds also had differentiation potential. These results suggested that the combination of PCL nanofibrous scaffolds and hE-cadherin-Fc fusion protein may be a promising artificial ECM for the behavior of hMSCs in vitro.

In vivo mouse

The aim of this in vivo study was to evaluate the feasibility of ^{99m}Tc-labeled cartilage link protein (CLP) probe for the single-photon emission computed tomography (SPECT) of lung cancer. Xenograft mouse model were established from a luciferase expressing cell line derived from a human lung cancer. Bioluminescence imaging (BLI) was carried out prior to ^{99m}Tc-CLP and ^{99m}Tc-methoxyisobutyl isonitrile (MIBI) SPECT scans. The image quality of ^{99m}Tc-CLP scan was validated with BLI and compared with well established ^{99m}Tc-MIBI scan. Results of multimodal imaging analyses suggested that ^{99m}Tc-CLP was a sensitive and reliable SPECT agent for lung cancer imaging.

Integrin-mediated adhesion of human mesenchymal stem cells to extracellular matrix proteins adsorbed to polymer surfaces.

In vitro, degradable aliphatic polyesters are widely used as cell carriers for bone tissue engineering, despite their lack of biological cues. Their biological active surface is rather determined by an adsorbed layer of proteins from the surrounding media. Initial cell fate, including adhesion and proliferation, which are key properties for efficient cell carriers, is determined by the adsorbed layer of proteins. Herein we have investigated the ability of human bone marrow derived stem cells (hBMSC) to adhere to extracellular matrix (ECM) proteins, including fibronectin and vitronectin which are present in plasma and serum. hBMSC expressed integrins for collagens, laminins, fibronectin and vitronectin. Accordingly, hBMSC strongly adhered to these purified ECM proteins by using the corresponding integrins. Although purified fibronectin and vitronectin adsorbed to aliphatic polyesters to a lower extent than to cell culture polystyrene, these low levels were sufficient to mediate adhesion of hBMSC. It was found that plasma- and serum-coated polystyrene adsorbed significant levels of both fibronectin and vitronectin, and fibronectin was identified as the major adhesive component of plasma for hBMSC; however, aliphatic polyesters adsorbed minimal levels of fibronectin under similar conditions resulting in impaired cell adhesion. Altogether, the results suggest that the efficiency of aliphatic polyesters cell carriers could be improved by increasing their ability to adsorb fibronectin.

Oxidative nanopatterning of titanium surfaces promotes production and extracellular accumulation of osteopontin.

The bone-biomaterial interface has been characterized by layers of afibrillar extracellular matrix (ECM) enriched in non collagenous proteins, including osteopontin (OPN), a multifunctional protein that in bone controls cell adhesion and ECM mineralization. Physical and chemical aspects of biomaterial surfaces have been demonstrated to affect cell-ECM-substrate interactions. The present paper described the ability of oxidative nanopatterning of titanium (Ti) surfaces to control extracellular OPN deposition in vitro. Ti discs were chemically treated by a mixture of H2SO4/H2O2 for either 30 min [Nano(30') Ti] or 4 h [Nano(4h) Ti]. Non-etched Ti discs were used as control. Primary osteogenic cells derived from newborn rat calvarial bone were plated on control and etched Ti and grown under osteogenic conditions up to 7 days. High resolution scanning electron microscopy revealed that treated Ti discs exhibited a nanoporous surface and that areas of larger nanopits were noticed only for Nano(4h) Ti. Large extracellular OPN accumulation were detectable only for Nano(4h) Ti, which was associated with OPN-positive cells with typical aspects of migrating cells. At day 3, quantitative results in terms of areas of OPN labeling were as follows: Nano(4h) Ti > Nano(30') Ti > Control Ti. In conclusion, chemically nanostructured Ti surfaces may support the enhancement of endogenous extracellular OPN deposition by osteogenic cells in vitro depending on the etching time, a finding that should be taken into consideration in strategies to biofunctionalize implant surfaces with molecules with cell adhesion capacity.

Oxidative nanopatterning of titanium surfaces promotes production and extracellular accumulation of osteopontin

The bone-biomaterial interface has been characterized by layers of afibrillar extracellular matrix (ECM) enriched in non collagenous proteins, including osteopontin (OPN), a multifunctional protein that in bone controls cell adhesion and ECM mineralization. Physical and chemical aspects of biomaterial surfaces have been demonstrated to affect cell-ECM-substrate interactions. The present paper described the ability of oxidative nanopatterning of titanium (Ti) surfaces to control extracellular OPN deposition in vitro. Ti discs were chemically treated by a mixture of H2SO4/H2O2 for either 30 min [Nano(30') Ti] or 4 h [Nano(4h) Ti]. Non-etched Ti discs were used as control. Primary osteogenic cells derived from newborn rat calvarial bone were plated on control and etched Ti and grown under osteogenic conditions up to 7 days. High resolution scanning electron microscopy revealed that treated Ti discs exhibited a nanoporous surface and that areas of larger nanopits were noticed only for Nano(4h) Ti. Large extracellular OPN accumulation were detectable only for Nano(4h) Ti, which was associated with OPN-positive cells with typical aspects of migrating cells. At day 3, quantitative results in terms of areas of OPN labeling were as follows: Nano(4h) Ti > Nano(30') Ti > Control Ti. In conclusion, chemically nanostructured Ti surfaces may support the enhancement of endogenous extracellular OPN deposition by osteogenic cells in vitro depending on the etching time, a finding that should be taken into consideration in strategies to biofunctionalize implant surfaces with molecules with cell adhesion capacity.

A interface osso-implante é caracterizada pela presença de uma camada de matriz extracellular (MEC) afibrilar rica em proteínas não-colágenas, incluindo osteopontina (OPN), cujas funções no tecido ósseo estão relacionadas à adesão celular e ao controle do processo de mineralização da MEC (crescimento de cristais). Aspectos físicos e químicos das superfícies de biomateriais podem afetar as interações célula-MEC-substrato. O objetivo do presente estudo foi demonstrar a capacidade de aspectos nanotopográficos de superfície de titânio (Ti) de controlar a deposição extracelular de OPN in vitro. Discos de Ti foram tratados quimicamente por solução de H2SO4/H2O2 durante 30 min [Nano(30') Ti] ou 4 h [Nano(4h) Ti]. Superfícies de Ti não tratadas foram usadas como controle. Células osteogênicas primárias derivadas de calvárias de ratos recém-nascidos foram plaqueadas sobre os discos de Ti e cultivadas em condições osteogênicas por até 7 dias. Microscopia eletrônica de varredura de alta resolução revelou que os discos de Ti tratados quimicamente exibiam superfície nanoporosa, com áreas de nanoporos maiores para Nano(4h) Ti. Apenas para esse grupo detectavam-se acúmulos extensos de OPN extracelular, os quais se distribuíam em áreas adjacentes a células OPN-positivas, com aspectos morfológicos típicos de células em migração. Em conclusão, a nanoestruturação química de superfície de Ti pode favorecer o aumento da deposição extracelular de OPN endógena por células osteogênicas in vitro, dependendo do tempo de condicionamento utilizado, o que deve ser considerado no desenvolvimento de estratégias para funcionalizar superfícies de implantes com moléculas com reconhecido efeito no processo de adesão celular.

beta-dystrobrevin, a kinesin-binding receptor, interacts with the extracellular matrix components pancortins.

The dystrobrevins (alpha and beta) are components of the dystrophin-associated protein complex (DPC), which links the cytoskeleton to the extracellular matrix and serves as a scaffold for signaling proteins. The precise functions of the beta-dystrobrevin isoform, which is expressed in nonmuscle tissues, have not yet been determined. To gain further insights into the role of beta-dystrobrevin in brain, we performed a yeast two-hybrid screen and identified pancortin-2 as a novel beta-dystrobrevin-binding partner. Pancortins-1-4 are neuron-specific olfactomedin-related glycoproteins, highly expressed during brain development and widely distributed in the mature cerebral cortex of the mouse. Pancortins are important constituents of the extracellular matrix and are thought to play an essential role in neuronal differentiation. We characterized the interaction between pancortin-2 and beta-dystrobrevin by in vitro and in vivo association assays and mapped the binding site of pancortin-2 on beta-dystrobrevin to amino acids 202-236 of the beta-dystrobrevin molecule. We also found that the domain of interaction for beta-dystrobrevin is contained in the B part of pancortin-2, a central region that is common to all four pancortins. Our results indicate that beta-dystrobrevin could interact with all members of the pancortin family, implying that beta-dystrobrevin may be involved in brain development. We suggest that dystrobrevin, a motor protein receptor that binds kinesin heavy chain, might play a role in intracellular transport of pancortin to specific sites in the cell.

Plant-based material, protein and biodegradable plastic.

Fibrous proteins from spiders, proteins with synthetic multiple repeats and mammalian structural proteins such as collagen have been produced in transgenic plants. Recent advances in the production of biodegradable plastic in plants also show the potential of molecular farming for research into and production of materials. Selection of a growing variety of such products, optimization of expression, and the development of effective purification strategies will further promote this growing field of biotechnology.

Desarrollo de un protocolo de análisis de la expresión génica mediante «differential display» que reduce el número de falsos positivos / The development of a protocol for the analysis of genetic expression through «differential display», as a means to reducing the number of false positives

Entre los métodos empleados para los análisis de la expresión de genes, el método de "differential display" ha sido ampliamente utilizado y, a pesar del uso extendido de los "microarrays", es aún un método válido para el análisis con muestras cuyo transcriptoma es desconocido. Con el objeto de reducir el elevado número de falsos positivos que genera esta técnica, hemos optimizado el protocolo para reducir la posibilidad de generar falsos positivos. En primer lugar, hemos marcado radiactivamente el cebador oligo-dT con lo que los fragmentos de DNA identificados son extremos 3'-UTR de RNAm. Por muestra hemos realizado dos transcripciones inversas y dos reacciones de PCR en cada una de ellas. Para seleccionar un fragmento de DNA, debía estar diferencialmente expresado en las 4 reacciones de PCR. Por último, todos los fragmentos fueron clonados y secuenciados por triplicado. Estas modificaciones al protocolo nos ha permitido identificar 5 genes expresados diferencialmente entre células epiteliales de intestino en estado proliferativo y diferenciado

The analysis of genetic expression, the differential display (DD) method has been widely used, but inspite of the extensive use of the «microarrays» method, it is still to be considered as a valid method for the analysis of samples whose transcriptone is not known. In this work, an attempt has been made to reduce the high number of false positives generated by this technique by optimising method protocol. As a preliminary step, we radioactively marked the oligo dT primer with which the fragments of identified DNA were extreme 3'-UTR of mRNA. For each sample two inverse transcriptions and two PCR reactions were performed. Only fragments of DNA that are expressed differentially in all 4 PCR reactions should be selected. Finally, all of the fragments were cloned and sequenced in triplicate. These protocol modifications have allowed us to identify 5 differentially expressed genes, in intestinal epithelial cells in both proliferative and differentiated states

Fibronectin in the plasma during pregnancy and parturition.

Fibronectin can be detected in the plasma and the extracellular matrix of the uterus of pregnant women. Studies so far have compared individual observations, whilst serial investigations during pregnancy, and during and after parturition have not been carried out. Plasma fibronectin levels were measured in 153 women with healthy pregnancies in relation to the gestational age. During parturition, blood was taken from the inception of labor through to parturition, and on the 1st, 3rd, and 5th days after parturition. The investigations of the plasma fibronectin level in pregnant women show constant concentrations up to the 35th week of pregnancy. From the 36th week onward the fibronectin rises significantly before dropping to the initial values at the start of labor. The elevated fibronectin concentration in the last 4 weeks before delivery could be explained both by renewed, elevated synthesis in the uterus and placenta as well as by lower consumption. The decline in the fibronectin level with the onset of labor could be caused by an elevated enzymatic induction in the uteroplacental unit in connection with the start of parturition.