Search results for "Fibronectin"

2017

We have engineered polymer-based microenvironments that promote vasculogenesis both in vitro and in vivo through synergistic integrin-growth factor receptor signalling. Poly(ethyl acrylate) (PEA) triggers spontaneous organization of fibronectin (FN) into nanonetworks which provide availability of critical binding domains. Importantly, the growth factor binding (FNIII12-14) and integrin binding (FNIII9-10) regions are simultaneously available on FN fibrils assembled on PEA. This material platform promotes synergistic integrin/VEGF signalling which is highly effective for vascularization events in vitro with low concentrations of VEGF. VEGF specifically binds to FN fibrils on PEA compared to …

A 3D‑scaffold of PLLA induces the morphological differentiation and migration of primary astrocytes and promotes the production of extracellular vesi…

2019

The present study analyzed the ability of primary rat astrocytes to colonize a porous scaffold, mimicking the reticular structure of the brain parenchyma extracellular matrix, as well as their ability to grow, survive and differentiate on the scaffold. Scaffolds were prepared using poly-L-lactic acid (PLLA) via thermally-induced phase separation. Firstly, the present study studied the effects of scaffold morphology on the growth of astrocytes, evaluating their capability to colonize. Specifically, two different morphologies were tested, which were obtained by changing the polymer concentration in the starting solution. The structures were characterized by scanning electron microscopy, and a…

Fibronectin-binding nanoparticles for intracellular targeting addressed by B. burgdorferi BBK32 protein fragments.

2011

Virus-like particles (VLPs) are created by the self-assembly of multiple copies of envelope and/or capsid proteins from many viruses, mimicking the conformation of a native virus. Such noninfectious nanostructures are mainly used as antigen-presenting platforms, especially in vaccine research; however, some of them recently were used as scaffolds in biotechnology to produce targeted nanoparticles for intracellular delivery. This study demonstrates the creation of fusion VLPs using hepatitis B core protein-based system maintaining a fibronectin-binding property from B. burgdorferi BBK32 protein, including the evidence of particles’ transmission to BHK-21 target cells via caveolae/rafts endoc…

Association between irisin and homocysteine in euglycemic and diabetic subjects

2014

Abstract Objectives The aim of study was to explore whether a relationship exists between homocysteine and irisin in type 2 diabetes (T2D) patients—a population with a high risk of developing cardiovascular disease—and euglycemic controls. Design and methods 69 T2D patients and 75 control subjects (adjusted by body mass index (BMI)) were included in the study. Irisin and homocysteine concentrations and anthropometric and biochemical variables were determined. Results Levels of homocysteine were significantly higher (11.0 ± 3.0 vs 12.4 ± 4.2 μmol/l) and levels of irisin were lower (279 ± 58 vs 263 ± 38 ng/ml) in T2D patients. When both T2D and controls were considered, irisin was found to co…

Expression of adhesion factors and degrading proteins in primary and secondary glioblastomas and their precursor tumors.

2000

In tumor tissue specimens of 27 primary and 17 secondary glioblastomas and the precursor lesions, the immunohistochemical expression patterns of the membrane protein CD44s, the basal lamina proteins laminin, collagen IV, and fibronectin, the lectin galectin-3 recognizing tenascin and N-CAM as well as of the matrix-degrading enzymes matrix metalloproteinase MMP-2 and MMP-9, and cathepsin D were studied. Besides expression of basal lamina proteins in vessels, all glioblastomas and the precursor lesions showed strong immunoreactivity of CD44s, tenascin, galectin-3, and N-CAM which were restricted to solid tumor masses. Present in solid tumor areas, MMP-2, MMP-9 and cathepsin D were also strong…

ICAM-1 and α3β1 expression by bronchial epithelial cells and theirin vitromodulation by inflammatory and anti-inflammatory mediators

2000

Background: Adhesion molecules are involved in inflammatory and repair processes of the bronchial epithelium. ICAM-1 is mainly involved in inflammatory reactions, whereas integrins, such as α3β1, are mainly involved in repair processes. Methods: Using bronchial biopsies from 10 asthmatics and eight controls, we first evaluated by immunohistochemistry expression of α3β1 and ICAM-1 in intact and damaged epithelium. Then, using the human pulmonary epithelial cell line WI-26 VA, we studied, by flow-cytometry, the modulation of ICAM-1 and α3β1 expression, and, by ELISA, the release of fibronectin by proinflammatory cytokines, such as IL-5, and anti-inflammatory cytokines, such as IL-4, TGF-β, an…

Release of transforming growth factor-beta (TGF-β) and fibronectin by alveolar macrophages in airway diseases

1996

Abstract Asthma and chronic bronchitis are associated with airway remodelling, and airway macrophages are present in bronchial inflammation. TGF-β and fibronectin released by alveolar macrophages possess a fibrogenic potency. The potential role of alveolar macrophages in airway remodelling was studied in asthma and chronic bronchitis by the release of TGF-β and fibronectin. Alveolar macrophages were isolated by bronchoalveolar lavage in 14 control subjects, 14 asthmatics and 14 chronic bronchitics. The spontaneous and lipopolysaccharide (LPS)- or concanavalin A (Con A)-induced release of TGF-β and fibronectin was measured by ELISA. Alveolar macrophages from chronic bronchitics spontaneously…

Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy

1991

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies. In addition, we noted that this interaction was dose dependent, Ca2+ dependent, saturable, and not covalent, was inhibited by soluble FN, but not by a prior incubation of FN-coated plates with anti-human fibronectin antibodies, and appeared to involve …

Factors associated with circulating concentrations of irisin in the general population cohort of the ABCD study

2017

Animal studies have shown that irisin is a myokine secreted following physical exercise, and that it induces the remodeling of white adipose tissue toward brown adipose tissue. Therefore, a protective role of irisin against obesity, diabetes, and other metabolic and cardiovascular conditions has been hypothesized. However, data in humans are contradictory and few data are available concerning the general population.We aimed to evaluate the association between serum irisin concentrations and habitual physical activity, as well as other metabolic and cardiovascular factors in a general population in a Mediterranean area.We considered 858 consecutive individuals included in the ABCD (Alimentaz…

Extracellular matrix composition in COPD

2012

Extracellular matrix (ECM) composition has an important role in determining airway structure. We postulated that ECM lung composition of chronic obstructive pulmonary disease (COPD) patients differs from that observed in smoking and nonsmoking subjects without airflow obstruction. We determined the fractional areas of elastic fibres, type-I, -III and -IV collagen, versican, decorin, biglycan, lumican, fibronectin and tenascin in different compartments of the large and small airways and lung parenchyma in 26 COPD patients, 26 smokers without COPD and 16 nonsmoking control subjects. The fractional area of elastic fibres was higher in non-obstructed smokers than in COPD and nonsmoking controls…