Abstract 19922: Phosphatidylserine Receptor Upregulation in Stroke for Targeted Carrier Delivery

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Tao Peng ◽  
David D McPherson ◽  
Shao-Ling Huang

Introduction: The phosphatidylserine receptor (PSR) plays an important role in apoptosis and inflammation. Whether this receptor is expressed in damaged brain cells in the early stages of stroke is unknown. Hypothesis: The purpose of this study was to determine if this receptor is expressed on ischemic neurovascular endothelial cells and if so, can it bind with PS-containing liposomes (PS-liposomes). The latter would allow for a neurovascular targeting strategy for therapeutic delivery to ischemic brain cells. Methods: Sprague Dawley rats (n=22) were randomly divided into sham, cerebral ischemia, and subarachnoid hemorrhage (SAH) injury groups. Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 2 hours using an intraluminal suture method. SAH was induced by an endovascular perforation method. Brain tissue was harvested for immunofluorescence staining at day 2 after surgery. Cultured human umbilical vein endothelial cells (HUVEC) were pre-treated with tumor necrosis factor alpha (TNFα) to stimulated PSR. Fluorescence labeled PS-containing liposomes (FITC-PS-Liposomes) were used. The PSR expression and the adhesion of liposomes were observed using fluorescence microscopy. Results: Normal brain tissue did not demonstrate PSR expression (Fig.1A). After brain injury, PSR expression was observed in the injured area and colocalized with the endothelium both in the MCAO (Fig.1B) and SAH animals (Fig.1C). Normal HUVEC did not demonstrate fluorescence (Fig.1D). Weak fluorescence was observed in normal cells that incorporated the PS-liposomes (Fig.1E). Strong fluorescence was observed in the TNFα-activated HUVEC that incorporated the FITC-PS-Liposomes (Fig.1F). Conclusions: This is first report that PSR expression occurs in cerebral microvascular endothelial cells in the early stages of stroke and can be recognized by PS-liposomes. This may allow development of a targeted liposomal carrier for novel targeted stroke treatment.

1992 ◽  
Vol 263 (4) ◽  
pp. C767-C772 ◽  
Author(s):  
C. L. Myers ◽  
S. J. Wertheimer ◽  
J. Schembri-King ◽  
T. Parks ◽  
R. W. Wallace

The intercellular adhesion molecule 1 (ICAM-1) is induced on endothelial cells by tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and lipopolysaccharide (LPS). We have reported the sensitivity of cytokine-induced ICAM-1 expression to protein kinase inhibitors, including inhibitors of protein kinase C (PKC) [C. L. Myers, S. N. Desai, J. Schembri-King, G. L. Letts, and R. W. Wallace. Am. J. Physiol. 262 (Cell Physiol. 31): C365-C373, 1992]. To directly investigate the role of PKC in ICAM-1 induction, we downregulated PKC by pretreatment of human umbilical vein endothelial cells with phorbol 12-myristate 13-acetate (PMA) and assessed ICAM-1 protein and mRNA induction elicited by subsequent exposure to inflammatory stimuli. PMA treatment results in ICAM-1 protein induction that declines to basal levels by 3 days. Western blots of endothelial cell lysates reveal a nearly complete loss of immunologically reactive PKC. Subsequent activation with cytokine or LPS leads to reinduction of ICAM-1 protein and mRNA; however, the cells no longer produced substantial amounts of ICAM-1 protein or mRNA in response to PMA stimulation. Cross desensitization is observed with phorbol dibutyrate, while 4 alpha-phorbol has no desensitizing effect. The data indicate that PKC activation, while capable of inducing ICAM-1 expression, is not essential for ICAM-1 induction by the inflammatory mediators TNF-alpha, IL-1 beta, or LPS.


2003 ◽  
Vol 10 (4) ◽  
pp. 558-563 ◽  
Author(s):  
C. S. M. Oude Nijhuis ◽  
E. Vellenga ◽  
S. M. G. J. Daenen ◽  
W. A. Kamps ◽  
E. S. J. M. de Bont

ABSTRACT Cancer patients who are leukopenic due to chemotherapy are susceptible to bacterial infections. Normally, clinical conditions during bacterial infections are caused by pathogen-associated molecular patterns, which are components that bind to Toll-like receptor (TLR) 2 (TLR-2) and TLR-4 on leukocytes, resulting in the production of inflammatory cytokines. The mechanism of this inflammatory response in cancer patients with diminished numbers of leukocytes is not completely clear. The levels of interleukin 1β (IL-1β) and tumor necrosis factor alpha measured in the circulation of leukopenic cancer patients are lower than those measured in that of nonleukopenic patients during bacterial infections, whereas plasma interleukin 8 (IL-8) levels show distinct identical increases during bacterial infections in both leukopenic and nonleukopenic patients. Normally, these cytokines are mainly secreted by leukocytes. In cancer patients with bacterial infections and a diminished number of leukocytes, other sources of IL-8 production, such as endothelial cells, might be expected. Endothelial cells instead of leukocytes become the most important producers of IL-8 during bacterial infections in patients with chemotherapy-induced leukopenia through TLR-2 and TLR-4 signaling. Whole blood samples from six cancer patients were stimulated with lipopolysaccharide (LPS), and then IL-8 concentrations in supernatants were measured. Further, human umbilical vein endothelial cells (HUVECs) were incubated with sera from leukopenic cancer patients with or without bacterial infections, and then IL-8 concentrations in supernatants were measured (n = 6). In addition, the same HUVEC experiment was performed with the addition of neutralizing antibodies against TLR-2 and TLR-4. During leukopenia (<109 cells/liter), LPS stimulation of whole blood did not result in an increase in IL-8 levels. However, when endothelial cells were incubated with sera from leukopenic cancer patients during bacterial infections, a three- to eightfold increase in IL-8 production was found, compared to the IL-8 production found after incubation with sera from patients without signs of infections. This increase did not reflect a higher level of IL-8 already present in the sera. Further, we demonstrated that IL-8 production induced in endothelial cells by sera from patients with documented gram-negative infections could be reduced significantly by up to 40% when the cells were incubated with neutralizing antibodies against TLR-4 (P = 0.028). The addition of TLR-2 antibodies slightly enhanced the reduction of IL-8 production. These results suggest that during bacterial infections in cancer patients with markedly diminished numbers of leukocytes, endothelial cells become important producers of IL-8 through TLR-4 signaling and, to a lesser extent, TLR-2 signaling.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Dongdong Zhang ◽  
Abhinav Srinath ◽  
Andrew J Kinloch ◽  
Robert Shenkar ◽  
Le Shen ◽  
...  

Introduction: Previous studies have reported robust inflammatory cell infiltration, selective synthesis of IgG, B-cell clonal expansion, and deposition of immune complexes and complement within Cerebral Cavernous Malformation (CCM) lesions. Furthermore,B-cell depletion has been shown to reduce the maturation of CCM in murine models. We hypothesize that specific autoantigen(s) within the lesional milieu trigger the pathogenetic immune responses in CCMs. This study aims to identify those putative autoantigen(s) using recombinant antibodies (rAbs) derived from plasma cells found in surgical human CCM lesions. Methods: CD138 + plasma cells were laser captured from fresh frozen surgically resected human CCM lesions. Clonally expanded immunoglobulin heavy- and light-chain variable region pairs were cloned into IgG expression vectors and expressed as monoclonal antibodies. Purified rAbs were assayed by immunofluorescence with CCM lesion tissue and normal brain tissue sections. rAbs assayed by immunocytochemistry with human primary cell line were used to further define the staining pattern. The cell lysates were immunoprecipitated with rAb, after protein purification by SDS-PAGE, and analyzed by Mass spectrometry. Results: In normal brain tissue, rAbs stained endothelial cells with limited staining of glial cells. In CCM lesional tissue, rAbs stained endothelial cells, glial cells as well as structures in the acellular matrix adjacent to caverns. In cultured Human Brain Microvascular Endothelial Cells (HBMECs) and Human Astrocytes (HAs), rAbs co-localized with cytoplasmic components. After HBMEC and HA cell lysates were immunoprecipitated with rAb, a Coomassie Stain detected bands of approximately 50 kDa. Conclusions: Our results suggest that autoantigen(s) in human CCM lesions are cytoplasmic components present in lesional tissue as well as in normal brain tissue. Molecular level identification of the triggering antigen is still ongoing by mass spectrometry. Identification of the autoantigen(s) in the lesional milieu might explain the propensity of lesion development from leaky endothelium in the neuroglial parenchyma. Characterization of the autoantigen triggers will open new venues for therapy or vaccine in this disease.


Blood ◽  
1991 ◽  
Vol 78 (8) ◽  
pp. 2027-2035 ◽  
Author(s):  
N Busso ◽  
S Huet ◽  
E Nicodeme ◽  
J Hiernaux ◽  
F Hyafil

Tissue factor (TF) is the first factor of the extrinsic pathway of coagulation. Normally, TF is not expressed on the surface of endothelial cells. However, expression of TF can be induced in these cells in response to stimulation by diverse inflammatory mediators such as interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF- alpha), lipopolysaccharide (LPS), and phorbol 12-myristate 13-acetate (PMA). We have studied the effect of these mediators on the kinetics of the induction of TF-related procoagulant activity (PCA) on human umbilical vein endothelial cells (HUVECs). PCA is transiently induced on HUVECs, attaining a peak some 4 to 8 hours after addition of inflammatory agents, with maximal accumulation of TF messenger RNA (mRNA) occurring 3 to 5 hours earlier. Because the expression of PCA by treated HUVECs returns to basal levels by 20 to 30 hours, we examined the response of these cells to a second inflammatory stimulus. Continuous incubation of cells with a single inflammatory agent for 24 to 48 hours induces a hyporesponsive state with respect to the reinduction of TF expression by the same agent (14% of the initial stimulation for IL-1 beta, 39% for TNF-alpha 30% for LPS, and 7% for PMA). Such a diminution in PCA was also observed in the levels of TF mRNA. By contrast, pretreatment of HUVECs with one agent did not dramatically affect the reinduction of TF by any of the three other factors. We subsequently focused our attention on the induction of the autologous refractory period by IL-1 beta. De novo protein synthesis was not required during the preincubation of ECs for hyporesponsiveness to be observed. The establishment of the refractory state did not depend on the downmodulation of IL-1 beta receptor affinity or expression. Moreover, pretreatment of HUVECs with IL-1 beta increased prostacyclin (PGI2) production in response to a second stimulation by IL-1 beta, although such cells were unable to reexpress TF under the same conditions. This result suggests that distinct secondary messenger pathways are involved in TF induction and PGI2 synthesis by IL-1 beta in HUVECs.


2017 ◽  
Vol 49 (7) ◽  
pp. 339-345 ◽  
Author(s):  
Tse-Shun Huang ◽  
Kuei-Chun Wang ◽  
Sara Quon ◽  
Phu Nguyen ◽  
Ting-Yu Chang ◽  
...  

The long noncoding RNAs (lncRNAs), which constitute a large portion of the transcriptome, have gained intense research interest because of their roles in regulating physiological and pathophysiological functions in the cell. We identified from RNA-Seq profiling a set of lncRNAs in cultured human umbilical vein endothelial cells (HUVECs) that are differentially regulated by atheroprotective vs. atheroprone shear flows. Among the comprehensively annotated lncRNAs, including both known and novel transcripts, LINC00341 is one of the most abundant lncRNAs in endothelial cells. Moreover, its expression level is enhanced by atheroprotective pulsatile shear flow and atorvastatin. Overexpression of LINC00341 suppresses the expression of vascular cell adhesion molecule 1 (VCAM1) and the adhesion of monocytes induced by atheroprone flow and tumor necrosis factor-alpha. Underlying this anti-inflammatory role, LINC00341 guides enhancer of zest homolog 2, a core histone methyltransferase of polycomb repressive complex 2, to the promoter region of the VCAM1 gene to suppress VCAM1. Network analysis reveals that the key signaling pathways (e.g., Rho and PI3K/AKT) are co-regulated with LINC00341 in endothelial cells in response to pulsatile shear. Together, these findings suggest that LINC00341, as an example of lncRNAs, plays important roles in modulating endothelial function in health and disease.


2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Priscilla Das ◽  
Nyi Nyi Naing ◽  
Nadiah Wan Arfah ◽  
KON Noorjan ◽  
Yee Cheng Kueh ◽  
...  

Introduction: Astrocytic gliomas are the most common and lethal intracranial brain tumours and rely on angiogenesis for the tumour development. Endothelial progenitor cells (EPCs) contribute to the angiogenesis of glioma tumour. Objectives: The study aimed to investigate the matured circulating endothelial cells population in the peripheral blood mononuclear cells (PBMCs) and its associations with tissue resident angiogenic cells in astrocytic glioma patients. Methods: A total of 22 astrocytic glioma patients were recruited from Hospital Universiti Sains Malaysia. Tumour were sliced and stained with CD133+ and VEGFA+ for angiogenic cells (n=22). The circulating (CD133-/VEGFR2+) matured endothelial cells in PBMCs (n=22) were quantified using FACS. The paired t-test and Pearson correlation test were used for the data analysis. Results: The angiogenic cells in brain tumour tissue were significantly higher compared to adjacent normal brain tissue (median 1.07±0.96% vs. median 0.69±0.68%; Wilcoxon signed rank test Z=-3.100; p=0.002). Positive correlation was found between the angiogenic cells of brain tumour tissue and adjacent normal brain tissue (Spearman’s rho correlation test, r=0.56; p=0.007). Significant positive correlation was found between matured endothelial cells in peripheral circulating systems and angiogenic cells in tumour of astrocytic glioma patients (Pearson correlation test, r=0.60, p=0.003).Conclusion:The findings of the study give support to the possible roles of EPCs in astrocytic glioma patients. Thus targeting tissue resident angiogenic cells and matured circulating endothelial cells by antiangiogenic treatment might be useful to prevent the tumour growth.


2019 ◽  
Vol 20 (19) ◽  
pp. 4930 ◽  
Author(s):  
Francesco Vieceli Dalla Sega ◽  
Raffaella Mastrocola ◽  
Giorgio Aquila ◽  
Francesca Fortini ◽  
Claudia Fornelli ◽  
...  

Loss-of-function mutations of the gene encoding Krev interaction trapped protein 1 (KRIT1) are associated with the pathogenesis of Cerebral Cavernous Malformation (CCM), a major cerebrovascular disease characterized by abnormally enlarged and leaky capillaries and affecting 0.5% of the human population. However, growing evidence demonstrates that KRIT1 is implicated in the modulation of major redox-sensitive signaling pathways and mechanisms involved in adaptive responses to oxidative stress and inflammation, suggesting that its loss-of-function mutations may have pathological effects not limited to CCM disease. The aim of this study was to address whether KRIT1 loss-of-function predisposes to the development of pathological conditions associated with enhanced endothelial cell susceptibility to oxidative stress and inflammation, such as arterial endothelial dysfunction (ED) and atherosclerosis. Silencing of KRIT1 in human aortic endothelial cells (HAECs), coronary artery endothelial cells (HCAECs), and umbilical vein endothelial cells (HUVECs) resulted in increased expression of endothelial proinflammatory adhesion molecules vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) and in enhanced susceptibility to tumor necrosis factor alpha (TNF-α)-induced apoptosis. These effects were associated with a downregulation of Notch1 activation that could be rescued by antioxidant treatment, suggesting that they are consequent to altered intracellular redox homeostasis induced by KRIT1 loss-of-function. Furthermore, analysis of the aorta of heterozygous KRIT1+/− mice fed a high-fructose diet to induce systemic oxidative stress and inflammation demonstrated a 1.6-fold increased expression of VCAM-1 and an approximately 2-fold enhanced fat accumulation (7.5% vs 3.6%) in atherosclerosis-prone regions, including the aortic arch and aortic root, as compared to corresponding wild-type littermates. In conclusion, we found that KRIT1 deficiency promotes ED, suggesting that, besides CCM, KRIT1 may be implicated in genetic susceptibility to the development of atherosclerotic lesions.


1995 ◽  
Vol 269 (1) ◽  
pp. C42-C47 ◽  
Author(s):  
D. Macconi ◽  
M. Foppolo ◽  
S. Paris ◽  
M. Noris ◽  
S. Aiello ◽  
...  

Platelet-activating factor (PAF) is known to modulate polymorphonuclear leukocyte (PMN) adhesion to endothelial cells cultured under static conditions and activated by thrombin. In contrast, there are no data on the role of PAF in PMN adhesion to cells exposed to flow conditions and activated by stimuli other than thrombin. Here we used the PAF receptor antagonist L-659,989 to evaluate PMN adhesion to human umbilical vein endothelial cells (HUVEC) in basal conditions or upon challenge with thrombin or tumor necrosis factor-alpha (TNF-alpha). Experiments were performed under dynamic flow using a parallel-plate flow chamber and a computer-based image analysis system. Rolling and adhesion of PMNs to endothelial cells significantly increased upon stimulation with thrombin. Thrombin-stimulated HUVEC also synthesized higher amounts of PAF than untreated cells. Pretreatment of PMNs with L-659,989 significantly reduced their rolling and adhesion to thrombin-activated HUVEC. Stimulation of HUVEC with TNF-alpha significantly increased the number of rolling and adherent PMNs as compared with untreated cells. Adhesion of PMNs to and migration across TNF-alpha-stimulated HUVEC were reduced by L-659,989, whereas cell rolling was unchanged. We conclude that PAF mediates leukocyte interaction under flow conditions with HUVEC activated by inflammatory stimuli.


2020 ◽  
Vol 21 (10) ◽  
pp. 3618 ◽  
Author(s):  
Anna Kloska ◽  
Marcelina Malinowska ◽  
Magdalena Gabig-Cimińska ◽  
Joanna Jakóbkiewicz-Banecka

Stroke is a severe neurological disorder in humans that results from an interruption of the blood supply to the brain. Worldwide, stoke affects over 100 million people each year and is the second largest contributor to disability. Dyslipidemia is a modifiable risk factor for stroke that is associated with an increased risk of the disease. Traditional and non-traditional lipid measures are proposed as biomarkers for the better detection of subclinical disease. In the central nervous system, lipids and lipid mediators are essential to sustain the normal brain tissue structure and function. Pathways leading to post-stroke brain deterioration include the metabolism of polyunsaturated fatty acids. A variety of lipid mediators are generated from fatty acids and these molecules may have either neuroprotective or neurodegenerative effects on the post-stroke brain tissue; therefore, they largely contribute to the outcome and recovery from stroke. In this review, we provide an overview of serum lipids associated with the risk of ischemic stroke. We also discuss the role of lipid mediators, with particular emphasis on eicosanoids, in the pathology of ischemic stroke. Finally, we summarize the latest research on potential targets in lipid metabolic pathways for ischemic stroke treatment and on the development of new stroke risk biomarkers for use in clinical practice.


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