scholarly journals The Interaction of Streptococcus pneumoniae with Plasmin Mediates Transmigration across Endothelial and Epithelial Monolayers by Intercellular Junction Cleavage

2008 ◽  
Vol 76 (11) ◽  
pp. 5350-5356 ◽  
Author(s):  
Cécile Attali ◽  
Claire Durmort ◽  
Thierry Vernet ◽  
Anne Marie Di Guilmi
Keyword(s):  
Streptococcus Pneumoniae ◽  
Protease Activity ◽  
Bacterial Attachment ◽  
Cell Junctions ◽  
Cell Junction ◽  
Vascular Endothelial ◽  
Plasmin Activity ◽  
Bacterial Surface

ABSTRACT The precise mechanisms by which Streptococcus pneumoniae overcomes epithelial and endothelial barriers to access underlying human tissues remain to be determined. The plasminogen system is highly important for the tissue barrier degradation which allows cell migration. Plasminogen is known to interact with pneumococci via enolase, glyceraldehyde-3-phosphate dehydrogenase, and choline-binding protein E. These observations prompted us to evaluate the role of this proteolytic system in the pneumococcal invasion process. We observed that coating of S. pneumoniae R6 strain with plasminogen or inactivated plasmin increased adherence to pulmonary epithelial A549 and vascular endothelial EaHy cells in vitro. This indicates that plasminogen-mediated adherence is independent of the protease activity and involves plasminogen binding to receptors on eukaryotic cell surfaces. Conversely, decreased adherence of bacterial cells coated with active plasmin was observed, indicating that the protease activity limits bacterial attachment on the cell surface. We were then interested in investigating the role of the proteolytic plasmin activity in the traversal of tissue barriers. We observed that adherence of plasmin-coated D39 (encapsulated) or R6 (unencapsulated) pneumococci induced sporadic disruptions of EaHy and A549 monolayer cell junctions. This was not observed when plasmin was inhibited by aprotinin. Endothelial junction disorganization may proceed by proteolysis of the cell junction components. This is supported by our observation of the in vitro cleavage by plasmin bound to pneumococci of recombinant vascular endothelial cadherin, the main component of endothelial adherens junctions. Finally, junction damage induced by plasmin may be related to tissue barrier traversal, as we measured an increase of S. pneumoniae transmigration across epithelial A549 and endothelial EaHy layers when active plasmin was present on the bacterial surface. Our results highlight a novel function for the plasminogen recruitment at the bacterial surface in facilitating adherence of pneumococci to endothelial and epithelial cells, while active plasmin degrades intercellular junctions. This process promotes migration of pneumococci through cell barriers by a pericellular route, a prerequisite for dissemination of S. pneumoniae in the host organism.

HGF receptor up-regulation contributes to the angiogenic phenotype of human endothelial cells and promotes angiogenesis in vitro

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4816-4822 ◽  
Author(s):  
Shunli Ding ◽  
Tatyana Merkulova-Rainon ◽  
Zhong Chao Han ◽  
Gérard Tobelem
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Growth Conditions ◽  
Cell Junctions ◽  
Mrna Levels ◽  
Vascular Endothelial ◽  
Antiangiogenic Therapies ◽  
Hepatocyte Growth

Abstract Hepatocyte growth factor (HGF) is a mesenchyme-derived pleiotropic growth factor and a powerful stimulator of angiogenesis, which acts on cells by binding to the c-met receptor. The exact role of the endogenous HGF/c-met system in one or more steps of the angiogenic process is not completely understood. To contribute to this question we used immunocytochemical analysis, Western blotting, and reverse transcription–polymerase chain reaction to study the expression of c-met in endothelial cells cultured in different growth conditions. We found that c-met is not colocalized with vascular endothelial (VE)–cadherin in cell-cell junctions. c-met and VE-cadherin were shown to be inversely regulated by cell density, at both the protein and the mRNA levels. We established that c-met is up-regulated during the in vitro recapitulation of several steps of angiogenesis. The c-met expression was increased shortly after switching to angiogenic growth conditions and remained high during the very first steps of angiogenesis, including cell migration, and cell proliferation. The endothelial cells in which the expression of c-met was up-regulated were more responsive to HGF and exhibited a higher rate of morphogenesis. Moreover, the antibody directed against the extracellular domain of the c-met inhibited angiogenesis in vitro. Our results suggest that c-met is a marker of angiogenic phenotype for endothelial cells and represents an attractive target for the development of new antiangiogenic therapies.

Group B Streptococcal and Pneumococcal Sepsis in Newborn Infants: The Role of Pneumococcal Antibody

PEDIATRICS ◽  
1978 ◽  
Vol 62 (4) ◽  
pp. 620-621
Author(s):  
Gerald W. Fischer ◽  
James W. Bass ◽  
George H. Lowell ◽  
Martin H. Crumrine
Keyword(s):  
Streptococcus Pneumoniae ◽  
Hydrochloric Acid ◽  
Group B Streptococcus ◽  
Newborn Infants ◽  
Polysaccharide Antigen ◽  
Type Iii ◽  
Pneumococcal Sepsis ◽  
Group B

The article by Bortolussi et al. on pneumococcal septicemia and meningitis in the neonat (Pediatrics 60:352, September 1977) was of great interest to us, since we have been analyzing the effect of antibody directed against Streptococcus pneumoniae on group B Streptococcus type III. We have recently shown (unpublished data) that antibody directed against S. pneumoniae type 14 precipitates the hot hydrochloric acid-extracted polysaccharide antigen of group B Streptococcus type III. Further studies have shown that this antibody is opsonic for group B Streptococcus type III in an in vitro bactericidal assay and protective in a suckling rat model of group B Streptococcus type III sepsis.1

Enhanced Vascular Endothelial Cell Function on Nanostructured Titanium Surface Features: The Role of Nano to Submicron Roughness

2008 ◽  
Vol 1136 ◽  
Author(s):  
Jing Lu ◽  
Dongwoo Khang ◽  
Thomas J. Webster
Keyword(s):  
Cell Adhesion ◽  
Endothelial Cell ◽  
Cell Function ◽  
Vascular Endothelial Cell ◽  
Vascular Endothelial ◽  
Endothelial Cell Function ◽  
Titanium Surfaces ◽  
Endothelial Cell Adhesion

ABSTRACTTo study the contribution of different surface feature properties in improving vascular endothelial cell adhesion, rationally designed nano/sub-micron patterns with various dimensions were created on titanium surfaces in this study. In vitro results indicated that endothelial cell adhesion was improved when the titanium pattern dimensions decreased into the nano-scale. Specifically, endothelial cells preferred to adhere on sub-micron and nano rough titanium substrates compared to flat titanium. Moreover, titanium with nano and sub-micron roughness and with the same chemistry as compared to flat titanium, had significantly greater surface energy. Thus, the present study indicated the strong potential of surface nanotopography and nano/sub-micron roughness for improving current vascular stent design.

scholarly journals A Protective Role of Paeoniflorin in Fluctuant Hyperglycemia-Induced Vascular Endothelial Injuries through Antioxidative and Anti-Inflammatory Effects and Reduction of PKCβ1

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jing-Shang Wang ◽  
Ye Huang ◽  
Shuping Zhang ◽  
Hui-Jun Yin ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Level ◽  
Umbilical Vein ◽  
Protective Role ◽  
Vascular Endothelial ◽  
Glucose Levels ◽  
Umbilical Vein Endothelial Cells

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.

scholarly journals Role of kinase-independent and -dependent functions of FAK in endothelial cell survival and barrier function during embryonic development

2010 ◽  
Vol 189 (6) ◽  
pp. 955-965 ◽  
Author(s):  
Xiaofeng Zhao ◽  
Xu Peng ◽  
Shaogang Sun ◽  
Ann Y.J. Park ◽  
Jun-Lin Guan
Keyword(s):  
Endothelial Cell ◽  
Normal Development ◽  
Vascular Development ◽  
Vascular Endothelial ◽  
Vascular Endothelial Cadherin ◽  
Abnormal Distribution ◽  
Endothelial Cell Survival ◽  
Independent Functions

Focal adhesion kinase (FAK) is essential for vascular development as endothelial cell (EC)–specific knockout of FAK (conditional FAK knockout [CFKO] mice) leads to embryonic lethality. In this study, we report the differential kinase-independent and -dependent functions of FAK in vascular development by creating and analyzing an EC-specific FAK kinase-defective (KD) mutant knockin (conditional FAK knockin [CFKI]) mouse model. CFKI embryos showed apparently normal development through embryonic day (E) 13.5, whereas the majority of CFKO embryos died at the same stage. Expression of KD FAK reversed increased EC apoptosis observed with FAK deletion in embryos and in vitro through suppression of up-regulated p21. However, vessel dilation and defective angiogenesis of CFKO embryos were not rescued in CFKI embryos. ECs without FAK or expressing KD FAK showed increased permeability, abnormal distribution of vascular endothelial cadherin (VE-cadherin), and reduced VE-cadherin Y658 phosphorylation. Together, our data suggest that kinase-independent functions of FAK can support EC survival in vascular development through E13.5 but are insufficient for maintaining EC function to allow for completion of embryogenesis.

scholarly journals Uremia Impacts VE-Cadherin and ZO-1 Expression in Human Endothelial Cell-to-Cell Junctions

Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 404 ◽  
Author(s):  
Rayana Maciel ◽  
Regiane Cunha ◽  
Valentina Busato ◽  
Célia Franco ◽  
Paulo Gregório ◽  
...  
Keyword(s):  
Protein Expression ◽  
Intercellular Junctions ◽  
Serum Levels ◽  
Endothelial Damage ◽  
Cell Junctions ◽  
Cell Junction ◽  
Uremic Serum ◽  
Gene And Protein Expression ◽  
The Impact

Endothelial dysfunction in uremia can result in cell-to-cell junction loss and increased permeability, contributing to cardiovascular diseases (CVD) development. This study evaluated the impact of the uremic milieu on endothelial morphology and cell junction’s proteins. We evaluated (i) serum levels of inflammatory biomarkers in a cohort of chronic kidney disease (CKD) patients and the expression of VE-cadherin and Zonula Occludens-1 (ZO-1) junction proteins on endothelial cells (ECs) of arteries removed from CKD patients during renal transplant; (ii) ECs morphology in vitro under different uremic conditions, and (iii) the impact of uremic toxins p-cresyl sulfate (PCS), indoxyl sulfate (IS), and inorganic phosphate (Pi) as well as of total uremic serum on VE-cadherin and ZO-1 gene and protein expression in cultured ECs. We found that the uremic arteries had lost their intact and continuous endothelial morphology, with a reduction in VE-cadherin and ZO-1 expression. In cultured ECs, both VE-cadherin and ZO-1 protein expression decreased, mainly after exposure to Pi and uremic serum groups. VE-cadherin mRNA expression was reduced while ZO-1 was increased after exposure to PCS, IS, Pi, and uremic serum. Our findings show that uremia alters cell-to-cell junctions leading to an increased endothelial damage. This gives a new perspective regarding the pathophysiological role of uremia in intercellular junctions and opens new avenues to improve cardiovascular outcomes in CKD patients.

Three-Dimensional Simulation of In Vitro Angiogenesis: Effects of Extracellular Matrix Structure and Density

2010 ◽  
Author(s):  
Lowell Taylor Edgar ◽  
James E. Guilkey ◽  
Clayton J. Underwood ◽  
Brenda Baggett ◽  
Urs Utzinger ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Chemical Factors ◽  
Dimensional Simulation ◽  
Endothelial Growth Factor ◽  
In Vitro Angiogenesis

The process of angiogenesis is regulated by both chemical and mechanical signaling. While the role of chemical factors such as vascular endothelial growth factor (VEGF) during angiogenesis has been extensively studied, the influence of the mechanostructural environment on new vessel generation has received significantly less attention. During angiogenesis, endothelial cells in the existing vasculature detach and migrate out into the surrounding extracellular matrix (ECM), forming tubular structures that eventually mature into new blood vessels. This process is modulated by the structure and composition of the ECM [1]. The ECM is then remodeled by endothelial cells in the elongating neovessel tip, resulting in matrix condensation and changes in fiber orientation [2]. The mechanism as to how angiogenic vasculature and the ECM influence each other is poorly understood.

scholarly journals PKM2 regulates endothelial cell junction dynamics and angiogenesis via ATP production

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jesús Gómez-Escudero ◽  
Cristina Clemente ◽  
Diego García-Weber ◽  
Rebeca Acín-Pérez ◽  
Jaime Millán ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Inflammatory Disease ◽  
Chronic Inflammatory Disease ◽  
Cell Junctions ◽  
Cell Junction ◽  
Collective Migration ◽  
Sprouting Angiogenesis ◽  
Cell Cell

Abstract Angiogenesis, the formation of new blood vessels from pre-existing ones, occurs in pathophysiological contexts such as wound healing, cancer, and chronic inflammatory disease. During sprouting angiogenesis, endothelial tip and stalk cells coordinately remodel their cell-cell junctions to allow collective migration and extension of the sprout while maintaining barrier integrity. All these processes require energy, and the predominant ATP generation route in endothelial cells is glycolysis. However, it remains unclear how ATP reaches the plasma membrane and intercellular junctions. In this study, we demonstrate that the glycolytic enzyme pyruvate kinase 2 (PKM2) is required for sprouting angiogenesis in vitro and in vivo through the regulation of endothelial cell-junction dynamics and collective migration. We show that PKM2-silencing decreases ATP required for proper VE-cadherin internalization/traffic at endothelial cell-cell junctions. Our study provides fresh insight into the role of ATP subcellular compartmentalization in endothelial cells during angiogenesis. Since manipulation of EC glycolysis constitutes a potential therapeutic intervention route, particularly in tumors and chronic inflammatory disease, these findings may help to refine the targeting of endothelial glycolytic activity in disease.

scholarly journals Absent in melanoma 2 inflammasome is required for host defence against Streptococcus pneumoniae infection

2019 ◽  
Vol 25 (7) ◽  
pp. 412-419 ◽  
Author(s):  
Siwei Feng ◽  
Tingting Chen ◽  
Guihua Lei ◽  
Fengqing Hou ◽  
Jiali Jiang ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pneumococcal Infection ◽  
Host Defence ◽  
Mortality And Morbidity ◽  
Caspase 1 ◽  
Pyrin Domain ◽  
Increased Susceptibility

Streptococcus pneumoniae, a leading cause of invasive pneumococcal disease, is responsible for high mortality and morbidity worldwide. A previous study showed that the NLR family pyrin domain containing 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammasomes are essential for caspase-1 activation and IL-1β production in the host response to S. pneumoniae infection. The function of NLRP3 in host innate immunity to S. pneumoniae was studied in vivo and in vitro. However, the role of AIM2 in host defence against S. pneumoniae remains unclear. Here, we show that AIM2-deficient (AIM2–/–) mice display increased susceptibility to intra-nasal infection with S. pneumoniae in comparison to wild type mice and that this susceptibility was associated with defective IL-1β production. Macrophages from AIM2–/– mice infected with S. pneumoniae showed impaired secretion of IL-1β as well as activation of the inflammasome, as determined by the oligomerisation of apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1 activation. Taken together, these results indicate that the AIM2 inflammasome is essential for caspase-1-dependent cytokine IL-1β production and eventual protection from pneumococcal infection in mice.

scholarly journals Role of Adhesin Release for Mucosal Colonization by a Bacterial Pathogen

2003 ◽  
Vol 197 (6) ◽  
pp. 735-742 ◽  
Author(s):  
Loïc Coutte ◽  
Sylvie Alonso ◽  
Nathalie Reveneau ◽  
Eve Willery ◽  
Brigitte Quatannens ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Wild Type ◽  
Early Step ◽  
Bacterial Surface ◽  
Extracellular Milieu ◽  
Wild Type Parent

Pathogen attachment is a crucial early step in mucosal infections. This step is mediated by important virulence factors called adhesins. To exert these functions, adhesins are typically surface-exposed, although, surprisingly, some are also released into the extracellular milieu, the relevance of which has previously not been studied. To address the role of adhesin release in pathogenesis, we used Bordetella pertussis as a model, since its major adhesin, filamentous hemagglutinin (FHA), partitions between the bacterial surface and the extracellular milieu. FHA release depends on its maturation by the specific B. pertussis protease SphB1. We constructed SphB1-deficient mutants and found that they were strongly affected in their ability to colonize the mouse respiratory tract, although they adhered even better to host cells in vitro than their wild-type parent strain. The defect in colonization could be overcome by prior nasal instillation of purified FHA or by coinfection with FHA-releasing B. pertussis strains, but not with SphB1-producing FHA-deficient strains, ruling out a nonspecific effect of SphB1. These results indicate that the release of FHA is important for colonization, as it may facilitate the dispersal of bacteria from microcolonies and the binding to new sites in the respiratory tract.

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