scholarly journals An Alternatively Spliced Variant of CXCR3 Mediates the Inhibition of Endothelial Cell Growth Induced by IP-10, Mig, and I-TAC, and Acts as Functional Receptor for Platelet Factor 4

2003 ◽  
Vol 197 (11) ◽  
pp. 1537-1549 ◽  
Author(s):  
Laura Lasagni ◽  
Michela Francalanci ◽  
Francesco Annunziato ◽  
Elena Lazzeri ◽  
Stefano Giannini ◽  
...  

The chemokines CXCL9/Mig, CXCL10/IP-10, and CXCL11/I-TAC regulate lymphocyte chemotaxis, mediate vascular pericyte proliferation, and act as angiostatic agents, thus inhibiting tumor growth. These multiple activities are apparently mediated by a unique G protein–coupled receptor, termed CXCR3. The chemokine CXCL4/PF4 shares several activities with CXCL9, CXCL10, and CXCL11, including a powerful angiostatic effect, but its specific receptor is still unknown. Here, we describe a distinct, previously unrecognized receptor named CXCR3-B, derived from an alternative splicing of the CXCR3 gene that mediates the angiostatic activity of CXCR3 ligands and also acts as functional receptor for CXCL4. Human microvascular endothelial cell line-1 (HMEC-1), transfected with either the known CXCR3 (renamed CXCR3-A) or CXCR3-B, bound CXCL9, CXCL10, and CXCL11, whereas CXCL4 showed high affinity only for CXCR3-B. Overexpression of CXCR3-A induced an increase of survival, whereas overexpression of CXCR3-B dramatically reduced DNA synthesis and up-regulated apoptotic HMEC-1 death through activation of distinct signal transduction pathways. Remarkably, primary cultures of human microvascular endothelial cells, whose growth is inhibited by CXCL9, CXCL10, CXCL11, and CXCL4, expressed CXCR3-B, but not CXCR3-A. Finally, monoclonal antibodies raised to selectively recognize CXCR3-B reacted with endothelial cells from neoplastic tissues, providing evidence that CXCR3-B is also expressed in vivo and may account for the angiostatic effects of CXC chemokines.

1999 ◽  
Vol 190 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Pila Estess ◽  
Animesh Nandi ◽  
Mansour Mohamadzadeh ◽  
Mark H. Siegelman

T cell recruitment to extralymphoid tissues is fundamental to the initiation and perpetuation of the inflammatory state during immune and autoimmune responses. Interleukin (IL)-15 is a proinflammatory cytokine whose described functions largely overlap with those of IL-2. The latter is attributable in large part to its binding of the heterotrimeric receptor that contains the β and γ chains of the IL-2R in combination with an unique IL-15Rα chain. However, unlike IL-2, IL-15 and its receptor have a wide tissue and cell type distribution, including endothelial cells. Here, we examine the effect of IL-15 on hyaluronan expression by endothelial cells, and investigate its role in vivo in promoting the extravasation of antigen-activated T cells through a CD44-dependent pathway. The expression of hyaluronan on primary endothelial cells and microvascular endothelial cell lines is induced by IL-15, whereas IL-2 has no such activity. Moreover, intraperitoneal administration of IL-15 or TNF-α in the absence of other exogenous proinflammatory stimuli allows the extravasation of superantigen-stimulated T cells into this site in vivo in a CD44-dependent manner. T cell recruitment induced by IL-15 requires expression of an intact IL-2Rβ chain, indicating that IL-15 operates in this context through the traditional IL-15R. The results suggest that IL-15 can regulate endothelial cell function and thereby enables a CD44-initiated adhesion pathway that facilitates entry of activated T lymphocytes into inflammatory sites. They further demonstrate a novel role for IL-15 (distinct from any of IL-2) in regulating microvascular endothelial cell adhesive function, help to understand the role of IL-15R expression on endothelium, and further support a central position for this cytokine in orchestrating multiple sequential aspects of T cell effector function and therefore chronic inflammatory processes.


2020 ◽  
Vol 21 (15) ◽  
pp. 5249 ◽  
Author(s):  
Anne-Claire Lagrée ◽  
Fabienne Fasani ◽  
Clotilde Rouxel ◽  
Marine Pivet ◽  
Marie Pourcelot ◽  
...  

Microvascular endothelial cells constitute potential targets for exogenous microorganisms, in particular for vector-borne pathogens. Their phenotypic and functional variations according to the organs they are coming from provide an explanation of the organ selectivity expressed in vivo by pathogens. In order to make available relevant tools for in vitro studies of infection mechanisms, our aim was to immortalize bovine organospecific endothelial cells but also to assess their permissivity to viral infection. Using transfection with SV40 large T antigen, six bovine microvascular endothelial cell lines from various organs and one macrovascular cell line from an umbilical cord were established. They display their own panel of endothelial progenitor/mature markers, as assessed by flow cytometry and RT-qPCR, as well as the typical angiogenesis capacity. Using both Bluetongue and foot-and-mouth disease viruses, we demonstrate that some cell lines are preferentially infected. In addition, they can be transfected and are able to express viral proteins such as BTV8-NS3. Such microvascular endothelial cell lines bring innovative tools for in vitro studies of infection by viruses or bacteria, allowing for the study of host-pathogen interaction mechanisms with the actual in vivo target cells. They are also suitable for applications linked to microvascularization, such as anti-angiogenic and anti-tumor research, growing fields in veterinary medicine.


2001 ◽  
Vol 69 (2) ◽  
pp. 845-852 ◽  
Author(s):  
Gregor Zysk ◽  
Barbara Katharina Schneider-Wald ◽  
Jae Hyuk Hwang ◽  
Levente Bejo ◽  
Kwang Sik Kim ◽  
...  

ABSTRACT In pneumococcal meningitis it is assumed that bacteria cross the blood-brain barrier (BBB), which consists mainly of cerebral endothelial cells. The effect of Streptococcus pneumoniaeon the BBB was investigated with an in vitro BBB model using a human brain microvascular endothelial cell line (HBMEC) and primary cultures of bovine brain microvascular endothelial cells (BBMEC). Within a few hours of incubation with pneumococci, rounding and detachment of the HBMEC were observed, and the transendothelial electrical resistance of the BBMEC monolayer decreased markedly. An S. pneumoniaemutant deficient in pneumolysin did not affect the integrity of the endothelial cell monolayer. Neither cell wall fragments nor isolated pneumococcal cell walls induced changes of endothelial cell morphology. However, purified pneumolysin caused endothelial cell damage comparable to that caused by the viable pneumococci. The cell detachment was dependent on de novo protein synthesis and required the activities of caspase and tyrosine kinases. The results show that pneumolysin is an important component for damaging the BBB and may contribute to the entry of pneumococci into the cerebral compartment and to the development of brain edema in pneumococcal meningitis.


1992 ◽  
Vol 1 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Carlton Young ◽  
Bruce E. Jarrell ◽  
James B. Hoying ◽  
Stuart K. Williams

The transplantation of endothelial cells represents a technology which has been suggested for applications ranging from improvement in function of implanted vascular devices to genetic therapy. The use of microvascular endothelial cell transplantation has seen increased use both in animal studies as well as clinical use. This report describes our techniques for the isolation and establishment of initial cultures of microvascular endothelial cells derived from porcine fat. A variety of anatomic sites within the pig were evaluated to determine the appropriateness of different sources of fat for endothelial cell isolation. The properitoneal fat was determined to be optimal due to the predominance of endothelium in this tissue and the ease of isolation of microvascular endothelium following collagenase digestion. The study of endothelial cell transplantation in the porcine model is now possible using the methods described for adipose tissue-derived micro vessel endothelial cell isolation.


Blood ◽  
2004 ◽  
Vol 103 (11) ◽  
pp. 4164-4172 ◽  
Author(s):  
Delphine-Armelle Lacorre ◽  
Espen S. Baekkevold ◽  
Ignacio Garrido ◽  
Per Brandtzaeg ◽  
Guttorm Haraldsen ◽  
...  

Abstract Endothelial cells display remarkable heterogeneity in different organs and vascular beds. Although many studies suggest that tissues “speak” to endothelial cells, endothelial cell diversity remains poorly characterized at the molecular level. Here, we describe a novel strategy to characterize tissue-specific endothelial cell phenotypes and to identify endothelial cell genes that are under the control of the local microenvironment. By comparing post-capillary high endothelial venule endothelial cells (HEVECs), freshly isolated from human tonsils without any cell culture step, with HEVECs cultured for 2 days, we found that HEVECs rapidly lost their specialized characteristics when isolated from the lymphoid tissue microenvironment. Striking changes occurred as early as after 48 hours, with complete loss of the postcapillary venule–specific Duffy antigen receptor for chemokines (DARCs) and the HEV-specific fucosyltransferase Fuc-TVII. DNA microarray analysis identified several other candidate HEV genes that were rapidly down-regulated ex vivo, including type XV collagen, which we characterized as a novel, abundant HEV transcript in situ. Together, our results demonstrate that blood vessel type–specific and tissue-specific characteristics of endothelial cells are under the control of their microenvironment. Therefore, even short-term primary cultures of human endothelial cells may not adequately mimic the differentiated endothelial cell phenotypes existing in vivo.


Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3206-3217 ◽  
Author(s):  
N Dubois-Stringfellow ◽  
A Jonczyk ◽  
VL Bautch

Abstract Fibrinolytic activity and its relation to morphogenesis was investigated in several transformed murine endothelial cell lines and primary cultures of endothelial cells. Two in vitro systems, fibrin gels and Matrigel (Collaborative Research, Bedford, MA), were used. Fibrin gels model a fibrin-rich extracellular matrix that frequently supports neovascularization in vivo, and Matrigel models the basement membrane surrounding quiescent endothelial cells in vivo. The transformed endothelial cell lines have higher levels of plasminogen activator (PA) mRNA than primary cultures of endothelial cells, and an increased PA-mediated proteolytic activity was correlated with formation of cysts in fibrin gels. Addition of neutralizing anti- urokinase antibodies, plasminogen depletion, or addition of a plasmin inhibitor prevented cyst formation. Addition of plasminogen restored the ability to form cysts in the plasminogen-depleted system. Normal endothelial cells organized into capillary-like structures in fibrin gels regardless of manipulations affecting the fibrinolytic pathway. In Matrigel, both transformed and primary cultures of endothelial cells rapidly formed a capillary-like network that was not affected by plasminogen depletion or addition of plasmin inhibitors. Thus, elements of the fibrinolytic pathway necessary for cyst formation are not critical in capillary-like structure formation on a reconstituted basement membrane. These results suggest that plasmin is essential for hemangioma formation but is not critical to the organizational behavior of normal endothelial cells.


Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 708
Author(s):  
Ana María Rodríguez ◽  
Aldana Trotta ◽  
Agustina P. Melnyczajko ◽  
M. Cruz Miraglia ◽  
Kwang Sik Kim ◽  
...  

Central nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. A common feature associated with this pathology is blood–brain barrier (BBB) activation. However, the underlying mechanisms involved with such BBB activation remain unknown. The aim of this work was to investigate the role of Brucella abortus-stimulated platelets on human brain microvascular endothelial cell (HBMEC) activation. Platelets enhanced HBMEC activation in response to B. abortus infection. Furthermore, supernatants from B. abortus-stimulated platelets also activated brain endothelial cells, inducing increased secretion of IL-6, IL-8, CCL-2 as well as ICAM-1 and CD40 upregulation on HBMEC compared with supernatants from unstimulated platelets. Outer membrane protein 19, a B. abortus lipoprotein, recapitulated B. abortus-mediated activation of HBMECs by platelets. In addition, supernatants from B. abortus-activated platelets promoted transendothelial migration of neutrophils and monocytes. Finally, using a pharmacological inhibitor, we demonstrated that the Erk1/2 pathway is involved in the endothelial activation induced by B. abortus-stimulated platelets and also in transendothelial migration of neutrophils. These results describe a mechanism whereby B. abortus-stimulated platelets induce endothelial cell activation, promoting neutrophils and monocytes to traverse the BBB probably contributing to the inflammatory pathology of neurobrucellosis.


2009 ◽  
Vol 96 (3) ◽  
pp. 682a
Author(s):  
Aydin Tay ◽  
William G. Mayhan ◽  
Denise Arrick ◽  
Chun-Hong Shao ◽  
Hong Sun ◽  
...  

2012 ◽  
Vol 302 (3) ◽  
pp. C505-C517 ◽  
Author(s):  
Breanna K. Wallace ◽  
Karen A. Jelks ◽  
Martha E. O'Donnell

Previous studies have provided evidence that, in the early hours of ischemic stroke, a luminal membrane blood-brain barrier (BBB) Na-K-Cl cotransporter (NKCC) participates in ischemia-induced cerebral edema formation. Inhibition of BBB NKCC activity by intravenous bumetanide significantly reduces edema and infarct in the rat permanent middle cerebral artery occlusion model of ischemic stroke. We demonstrated previously that the BBB cotransporter is stimulated by hypoxia, aglycemia, and AVP, factors present during cerebral ischemia. However, the underlying mechanisms have not been known. Ischemic conditions have been shown to activate p38 and JNK MAP kinases (MAPKs) in brain, and the p38 and JNK inhibitors SB-239063 and SP-600125, respectively, have been found to reduce brain damage following middle cerebral artery occlusion and subarachnoid hemorrhage, respectively. The present study was conducted to determine whether one or both of these MAPKs participates in ischemic factor stimulation of BBB NKCC activity. Cultured cerebral microvascular endothelial cell NKCC activity was evaluated as bumetanide-sensitive86Rb influx. Activities of p38 and JNK were assessed by Western blot and immunofluorescence methods using antibodies that detect total vs. phosphorylated (activated) p38 or JNK. We report that p38 and JNK are present in cultured cerebral microvascular endothelial cells and in BBB endothelial cells in situ and that hypoxia (7% O2and 2% O2), aglycemia, AVP, and O2-glucose deprivation (5- to 120-min exposures) all rapidly activate p38 and JNK in the cells. We also provide evidence that SB-239063 and SP-600125 reduce or abolish ischemic factor stimulation of BBB NKCC activity. These findings support the hypothesis that ischemic factor stimulation of the BBB NKCC involves activation of p38 and JNK MAPKs.


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