Search results for " vitro"

Exosomes derived from stimulated monocytes promote endothelial dysfunction and inflammation in vitro

2017

During the last few years, the scientific community interest on the role of extracellular vesicles (EVs) in physiology and pathophysiology of several human diseases has increased exponentially (1). These vesicles present the capability of transferring different kind of molecules (lipids, RNAs, DNA, protein…) between cells and may exert some effects on the cell phenotype. The content of these vesicles can vary depending on the cell type of origin (2). Although nowadays there is no consensus regarding the appropriate nomenclature, three well-known types of vesicles can be categorized on the basis of size and biogenesis: apoptotic bodies (>1 µm), microvesicles (150 nm–1 µm, budding from plasma…

Candida albicansis able to use M cells as a portal of entry across the intestinal barrierin vitro

2015

Candida albicans is the most frequent yeast responsible for systemic infections in humans. These infections mainly originate from the gastrointestinal tract where C. albicans can invade the gut epithelial barrier to gain access to the bloodstream. Along the gut, pathogens can use Microfold (M) cells as a portal of entry to cross the epithelial barrier. M cells are specialized cells mainly located in the follicule-associated epithelium of Peyer patches. In this study, we used scanning electron and fluorescence microscopy, adhesion and invasion assays and fungal mutants to investigate the interactions of C. albicans with M cells obtained in an established in vitro model whereby enterocyte-lik…

Visualizing In Vitro Type I Collagen Fibrillogenesis by Transmission Electron Microscopy

2017

Techniques and protocols for the in vitro formation of collagen type I fibrils and the extensive biochemical variation of the fibrillogenesis conditions are presented. In all cases, the incubation and fibrillogenesis product can be readily monitored by transmission electron microscopic study of negatively stained specimens. Representative TEM data is presented and discussed within the context of the products of the fibrillogenesis protocols, from which the extensive biochemical and structural possibilities of this integrated approach can be appreciated.

2017

Although a lot of research has been performed, large segmental bone defects caused by trauma, infection, bone tumors or revision surgeries still represent big challenges for trauma surgeons. New and innovative bone substitutes are needed. Three-dimensional (3D) printing is a novel procedure to create 3D porous scaffolds that can be used for bone tissue engineering. In the present study, solid discs as well as porous cage-like 3D prints made of polylactide (PLA) are coated or filled with collagen, respectively, and tested for biocompatibility and endotoxin contamination. Microscopic analyses as well as proliferation assays were performed using various cell types on PLA discs. Stromal-derived…

Uptake of polyphosphate microparticles in vitro (SaOS-2 and HUVEC cells) followed by an increase of the intracellular ATP pool size

2017

Recently two approaches were reported that addressed a vitally important problem in regenerative medicine, i. e. the successful treatment of wounds even under diabetic conditions. Accordingly, these studies with diabetic rabbits [Sarojini et al. PLoS One 2017, 12(4):e0174899] and diabetic mice [Müller et al. Polymers 2017, 9, 300] identified a novel (potential) target for the acceleration of wound healing in diabetes. Both studies propose a raise of the intracellular metabolic energy status via exogenous administration either of ATP, encapsulated into lipid vesicles, or of polyphosphate (polyP) micro-/nanoparticles. Recently this physiological polymer, polyP, was found to release metabolic …

2017

Better identification of severe acute graft-versus-host disease (GvHD) may improve the outcome of this life-threatening complication of allogeneic hematopoietic stem cell transplantation. GvHD induces tissue damage and the release of damage-associated molecular pattern (DAMP) molecules. Here, we analyzed GvHD patients (n = 39) to show that serum heat shock protein glycoprotein 96 (Gp96) could be such a DAMP molecule. We demonstrate that serum Gp96 increases in gastrointestinal GvHD patients and its level correlates with disease severity. An increase in Gp96 serum level was also observed in a mouse model of acute GvHD. This model was used to identify complement C3 as a main partner of Gp96 i…

Angiogenic response in an in vitro model of dog microvascular endothelial cells stimulated with antigenic extracts from Dirofilaria immitis adult wor…

2019

Abstract Background Angiogenesis can occur under pathological conditions when stimuli such as inflammation, vascular obstruction or hypoxia exist. These stimuli are present in cardiopulmonary dirofilariosis (Dirofilaria immitis). The aim of this study was to analyze the capacity of D. immitis antigens to modify the expression of angiogenic factors and trigger the formation of pseudocapillaries (tube-like structures) in an in vitro model of endothelial cells. Methods The expression of VEGF-A, sFlt, mEndoglin and sEndoglin in cultures of canine microvascular endothelial cells stimulated with extract of adult worms of D. immitis obtained from an untreated dog (DiSA) and from a dog treated for …

Drug metabolism by cultured human hepatocytes: how far are we from the in vivo reality?

2004

The investigation of metabolism is an important milestone in the course of drug development. Drug metabolism is a determinant of drug pharmacokinetics variability in human beings. Fundamental to this are phenotypic differences, as well as genotypic differences, in the expression of the enzymes involved in drug metabolism. Genotypic variability is easy to identify by means of polymerase chain reaction-based or DNA chip-based methods, whereas phenotypic variability requires direct measurement of enzyme activities in liver, or, indirectly, measurement of the rate of metabolism of a given compound in vivo. There is a great deal of phenotypic variability in human beings, only a minor part being…

Advantageous use of HepaRG cells for the screening and mechanistic study of drug-induced steatosis

2016

Only a few in vitro assays have been proposed to evaluate the steatotic potential of new drugs. The present study examines the utility of HepaRG cells as a cell-based assay system for screening drug-induced liver steatosis. A high-content screening assay was run to evaluate multiple toxicity-related cell parameters in HepaRG cells exposed to 28 compounds, including drugs reported to cause steatosis through different mechanisms and non-steatotic compounds. Lipid content was the most sensitive parameter for all the steatotic drugs, whereas no effects on lipid levels were produced by non-steatotic compounds. Apart from fat accumulation, increased ROS production and altered mitochondrial membra…

Metabolic activation and drug-induced liver injury:in vitroapproaches for the safety risk assessment of new drugs

2015

Drug-induced liver injury (DILI) is a significant leading cause of hepatic dysfunction, drug failure during clinical trials and post-market withdrawal of approved drugs. Many cases of DILI are unexpected reactions of an idiosyncratic nature that occur in a small group of susceptible individuals. Intensive research efforts have been made to understand better the idiosyncratic DILI and to identify potential risk factors. Metabolic bioactivation of drugs to form reactive metabolites is considered an initiation mechanism for idiosyncratic DILI. Reactive species may interact irreversibly with cell macromolecules (covalent binding, oxidative damage), and alter their structure and activity. This r…