Search results for " endothelial cells"
showing 10 items of 132 documents
Exosomes released by k562 chronic myeloid leukemia cells promote endothelial cell tubular differentiation through uptake and cell-to-cell transfer
2012
Exosomes, microvesicles of endocytic origin released by normal and tumor cells, play an important role in cell-to-cell ommunication. Angiogenesis has been shown to regulate progression of chronic myeloid leukemia (CML). The mechanism through which this happens has not been elucidated. We isolated and characterized exosomes from K562 CML cells and evaluated their effects on human umbilical endothelial cells (HUVECs). Fluorescent-labeled exosomes were nternalized by HUVECs during tubular differentiation on Matrigel. Exosome localization was perinuclear early in differentiation, moving peripherally in cells undergoing elongation and connection. Exosomes move within and between nanotubular stru…
Dysbiosis and zonulin upregulation alter gut epithelial and vascular barriers in patients with ankylosing spondylitis
2017
BackgroundDysbiosis has been recently demonstrated in patients with ankylosing spondylitis (AS) but its implications in the modulation of intestinal immune responses have never been studied. The aim of this study was to investigate the role of ileal bacteria in modulating local and systemic immune responses in AS.MethodsIleal biopsies were obtained from 50 HLA-B27+ patients with AS and 20 normal subjects. Silver stain was used to visualise bacteria. Ileal expression of tight and adherens junction proteins was investigated by TaqMan real-time (RT)-PCR and immunohistochemistry. Serum levels of lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), intestinal fatty acid-BP (iFABP) and zonulin…
A BMP7 Variant Inhibits Tumor Angiogenesis In Vitro and In Vivo through Direct Modulation of Endothelial Cell Biology
2015
Bone morphogenetic proteins (BMPs), members of the TGF-β superfamily, have numerous biological activities including control of growth, differentiation, and vascular development. Using an in vitro co-culture endothelial cord formation assay, we investigated the role of a BMP7 variant (BMP7v) in VEGF, bFGF, and tumor-driven angiogenesis. BMP7v treatment led to disruption of neo-endothelial cord formation and regression of existing VEGF and bFGF cords in vitro. Using a series of tumor cell models capable of driving angiogenesis in vitro, BMP7v treatment completely blocked cord formation. Pre-treatment of endothelial cells with BMP7v significantly reduced their cord forming ability, indicating …
Protective role of the complement regulatory protein human CD-55 in cardiac xenograft: a descriptive study and a revision of the literature.
2002
The limited and inadequate availability of organs from human donors has resulted in the utilisation of xenografts as an alternative tool. Nevertheless, hyperacute rejection (HAR) following xenograft determines the loss of the transplanted organ. The “primum movens” is the activation of the complement pathway mediated by the binding of natural xenogenic antibodies to the endothelium of the graft, followed by the lysis of the endothelial cells with subsequent oedema, thrombosis and necrosis of the transplanted organ. In this work we describe morphological and biomolecular observations of isolated human-decay accelerating factor (h-DAF, CD55) transgenic pig hearts, after perfusion for four hou…
Cellular and tissue expression of DAPIT, a phylogenetically conserved peptide
2011
DAPIT (Diabetes Associated Protein in Insulin-sensitive Tissues) is a small, phylogenetically conserved, 58 amino acid peptide that was previously shown to be down-regulated at mRNA level in insulin-sensitive tissues of type 1 diabetes rats. In this study we characterize a custom made antibody against DAPIT and confirm the mitochondrial presence of DAPIT on cellular level. We also show that DAPIT is localized in lysosomes of HUVEC and HEK 293T cells. In addition, we describe the histological expression of DAPIT in several tissues of rat and man and show that it is highly expressed especially in cells with high aerobic metabolism and epithelial cells related to active transport of nutrients …
Cross-talk between minimally primed HL-60 cells and resting HUVEC reveals a crucial role for adhesion over extracellularly released oxidants
2011
This study demonstrates that a long-lasting co-culture of neutrophil surrogates (HL-60 cells), minimally primed by platelet activating factor (PAF), and resting endothelial cells (EC) results in the elaboration of an hyper-adhesive endothelial surface, as measured by the increase in the expression of endothelial adhesion molecules E-Selectin, VCAM-1, and ICAM-1. This endothelial dysfunction is mediated by the activation of the redox-sensitive transcription factor NF-κB through an exclusive adhesion-driven mechanism active in the endothelial cell: reactive oxygen and nitrogen species, extracellularly released by minimally primed HL-60 cells, are not involved in the induction of the endotheli…
In vitro and in vivo characterization of porcine acellular dermal matrix for gingival augmentation procedures
2013
Recently, porcine acellular dermal matrix (PADM) has been proposed as a possible alternative to autogenous grafts in periodontal plastic surgery. The aim of the present study was to investigate the in vitro responses of four different oral cell lines cultured on a novel PADM. Furthermore, tissue reaction to PADM was evaluated histologically after subcutaneous implantation in mice.Human gingival fibroblasts (HGF), human osteoblast-like cells, human umbilical vein endothelial cells and human oral keratinocytes (HOK) were cultured and transferred on to the PADM. A tissue culture polystyrene surface served as the control. The viability of all tested cell lines on PADM was measured by using the …
Endothelialization and Anticoagulation Potential of Surface-Modified PET Intended for Vascular Applications.
2018
In vascular tissue engineering, great attention is paid to the immobilization of biomolecules onto synthetic grafts to increase bio- and hemocompatibility-two critical milestones in the field. The surface modification field of poly(ethylene terephthalate) (PET), a well-known vascular-graft material, is matured and oversaturated. Nevertheless, most developed methods are laborious multistep procedures generally accompanied by coating instability or toxicity issues. Herein, a straightforward surface modification procedure is presented engineered to simultaneously promote surface endothelialization and anticoagulation properties via the covalent immobilization of gelatin through a photoactivate…
Coagulation and fibrosis in chronic liver disease.
2008
In the hepatic tissue repair mechanism, hepatic stellate cells (HSCs) are recruited at the site of injury and their changes reflect paracrine stimulation by all neighbouring cell types, including sinusoidal endothelial cells, Kupffer cells, hepatocytes, platelets and leucocytes. Thrombin converts circulating fibrinogen to fibrin, promotes platelet aggregation, is a potent activator of endothelial cells, acts as a chemoattractant for inflammatory cells and is a mitogen and chemoattractant for fibroblasts and vascular smooth muscle cells. Most of the cellular effects elicited by thrombin are mediated via a family of widely expressed G-protein-coupled receptors termed protease activated recept…
The LepR-mediated leptin transport across brain barriers controls food reward
2018
Objective Leptin is a key hormone in the control of appetite and body weight. Predominantly produced by white adipose tissue, it acts on the brain to inhibit homeostatic feeding and food reward. Leptin has free access to circumventricular organs, such as the median eminence, but entry into other brain centers is restricted by the blood–brain and blood–CSF barriers. So far, it is unknown for which of its central effects leptin has to penetrate brain barriers. In addition, the mechanisms mediating the transport across barriers are unclear although high expression in brain barriers suggests an important role of the leptin receptor (LepR). Methods We selectively deleted LepR in brain endothelia…