scholarly journals Haemophilus somnus Induces Apoptosis in Bovine Endothelial Cells In Vitro

2001 ◽  
Vol 69 (3) ◽  
pp. 1650-1660 ◽  
Author(s):  
Matt J. Sylte ◽  
Lynette B. Corbeil ◽  
Thomas J. Inzana ◽  
Charles J. Czuprynski
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Dependent Manner ◽  
Endothelial Cell Apoptosis ◽  
Heat Stable ◽  
Culture Filtrates ◽  
Haemophilus Somnus ◽  
Bovine Endothelial Cells ◽  
Dose Dependent

ABSTRACT Haemophilus somnus causes pneumonia, reproductive failure, infectious myocarditis, thrombotic meningoencephalitis, and other diseases in cattle. Although vasculitis is commonly seen as a result of systemic H. somnus infections, the pathogenesis of vascular damage is poorly characterized. In this study, we demonstrated that H. somnus (pathogenic isolates 649, 2336, and 8025 and asymptomatic carrier isolates 127P and 129Pt) induce apoptosis of bovine endothelial cells in a time- and dose-dependent manner, as determined by Hoechst 33342 staining, terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick end labeling, DNA fragmentation, and transmission electron microscopy. H. somnus induced endothelial cell apoptosis in as little as 1 h of incubation and did not require extracellular growth of the bacteria. Viable H. somnus organisms induced greater endothelial cell apoptosis than heat-killed organisms. Since viableH. somnus cells release membrane fibrils and blebs, which contain lipooligosaccharide (LOS) and immunoglobulin binding proteins, we examined culture filtrates for their ability to induce endothelial cell apoptosis. Culture filtrates induced similar levels of endothelial cell apoptosis, as did viable H. somnus organisms. Heat inactivation of H. somnus culture filtrates partially reduced the apoptotic effect on endothelial cells, which suggested the presence of both heat-labile and heat-stable factors. We found thatH. somnus LOS, which is heat stable, induced endothelial cell apoptosis in a time- and dose-dependent manner and was inhibited by the addition of polymyxin B. These data demonstrate that H. somnus and its LOS induce endothelial cell apoptosis, which may play a role in producing vasculitis in vivo.

Induction of Endothelial Cell Apoptosis by Cleaved High Molecular Weight Kininogen Is Mediated Through a Lck and p53-Dependent Pathway

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3305-3305
Author(s):  
Venkaiah Betapudi ◽  
Keith R. McCrae
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
High Molecular Weight ◽  
Cell Apoptosis ◽  
Negative Regulator ◽  
Dependent Manner ◽  
High Molecular Weight Kininogen ◽  
Endothelial Cell Apoptosis ◽  
Single Chain

Abstract Abstract 3305 Background and objective: High molecular weight kininogen (HK) is an abundant plasma protein that serves as an important component of the intrinsic pathway of coagulation. HK normally circulates as in the single chain form, but may be cleaved by plasma kallikrein to release the nonapeptide bradykinin, resulting in the formation cleaved high molecular weight kininogen (HKa) that consists of a heavy and light chain linked by a single disulfide bond. Conformational changes occurring after kallikrein cleavage result in increased exposure of histidine and glycine-rich regions with kininogen domain 5 that impart HKa with unique properties, including the ability to inhibit angiogenesis by causing selective apoptosis of proliferating endothelial cells. However, the receptors that mediate the antiangiogenic activity of HKa remain controversial, and the signaling pathways that lead to apoptosis have not been defined. Previous studies suggested possible involvement of SRC family kinases (SFK) in this process, and the purpose of this work was to further define the activation of SFKs and their downstream targets during HKa-induced endothelial cell apoptosis. Results: We first assessed the activation of SFKs in proliferating endothelial cells stimulated with bFGF before and after incubation with HKa (6–20 nM). SFKs are maintained in an inactive state through tyrosine phosphorylation of their C-terminal region mediated by the negative regulator C-terminal Src kinase (Csk). Exposure of endothelial cells to HKa caused downregulation of Csk in a dose-dependent manner within 60 minutes. In parallel, we observed a significant increase in expression of the proapoptotic SFK Lck in endothelial cells exposed to HKa, though expression of other SFKs including Lyn, Fyn, Src, Hck and Blk were not significantly altered. Increased expression of Lck was associated with activation of p53 and increased expression of the pro-apoptotic Bcl-2 family members Bax and Bak. Endothelial cell lysates prepared within 60 minutes of exposure to HKa demonstrated significant increases in the activity of caspases 3 and 7, as well as depletion of DNA fragmentation factors (DFF) 45 and 35, which cleave and inactivate DFF40, a major endonuclease involved in apoptosis. In parallel studies, endothelial cells depleted of Lck by treatment with Lck siRNA displayed loss of p53 phosphorylation, caspase 3 and 7 activity, and expression of Bax and Bad with no effects on the expression of Bad and Bid. Conclusion: These findings demonstrate a critical role for Csk in regulation of SFK activation and endothelial homeostasis, and demonstrate that downregulation of Csk by HKa leads to activation of a Lck-dependent, p53-mediated apoptotic pathway. Increasing the expression of Lck may represent a novel mechanism for regulation of aberrant angiogenesis. Disclosures: No relevant conflicts of interest to declare.

Inhibition of angiogenesis by two-chain high molecular weight kininogen (HKa) and kininogen-derived polypeptides

2002 ◽  
Vol 80 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Jing-Chuan Zhang ◽  
Xiaoping Qi ◽  
Jose' Juarez ◽  
Marian Plunkett ◽  
Fernando Donaté ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
High Molecular Weight ◽  
Cell Apoptosis ◽  
Endothelial Cell Proliferation ◽  
Dependent Manner ◽  
High Molecular Weight Kininogen ◽  
Endothelial Cell Apoptosis ◽  
Domain 3

We recently reported that the two-chain form of human high molecular weight kininogen (HKa) inhibits angiogenesis by inducing endothelial cell apoptosis (Zhang et al. 2000). This property appears to be primarily conferred by HKa domain 5 (HKa D5). In this manuscript, we further characterize the activity of these polypeptides toward proliferating endothelial cells, as well as their in vivo anti-angiogenic activity in the chick chorioallantoic membrane (CAM). We also demonstrate that short peptides derived from endothelial cell binding regions in HKa domains 3 and 5 inhibit endothelial cell proliferation and induce endothelial cell apoptosis. Like HKa and HKa D5, peptides derived from the latter domain induce endothelial cell apoptosis in a Zn2+-dependent manner, while those derived from domain 3 function independently of Zn2+. The implications of these findings to the regulation of angiogenesis and development of anti-angiogenic therapeutics are discussed.Key words: angiogenesis, kininogen, endothelial cells, apoptosis, peptides.

15-Deoxy-Δ12,14-prostaglandin J2 and laminar fluid shear stress stabilize c-IAP1 in vascular endothelial cells

2003 ◽  
Vol 285 (1) ◽  
pp. H38-H46 ◽  
Author(s):  
Yoji Taba ◽  
Megumi Miyagi ◽  
Yoshikazu Miwa ◽  
Hiroyasu Inoue ◽  
Fumi Takahashi-Yanaga ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Expression Level ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Laminar Shear Stress ◽  
Endothelial Cell Apoptosis ◽  
Laminar Shear

Laminar shear stress strongly inhibits vascular endothelial cell apoptosis by unknown mechanisms. We reported that shear stress stimulates endothelial cells to produce 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) by elevating the expression level of lipocalin-type prostaglandin D synthase. To investigate the role of 15d-PGJ2 produced in the vascular wall, we examined the effect of 15d-PGJ2 on endothelial cell apoptosis. We induced apoptosis in human umbilical vein endothelial cells (HUVECs) by growth factor deprivation. 15d-PGJ2 strongly inhibited DNA ladder formation, nuclear fragmentation, and caspase-3-like activity in HUVECs. To elucidate the mechanism by which 15d-PGJ2 inhibits endothelial cell apoptosis, we examined expression of the inhibitor of apoptosis proteins (IAP) cellular-IAP1 (c-IAP1), c-IAP2, x-linked IAP, and survivin in HUVECs. In parallel with the inhibition of apoptosis, 15d-PGJ2 elevated the expression level of c-IAP1 protein in a dose- and time-dependent manner without changing the mRNA level. Laminar shear stress also induced c-IAP1 expression. Chase experiments with the use of cycloheximide revealed that 15d-PGJ2 and shear stress both inhibited the proteolytic degradation of c-IAP1 protein. These results suggested that 15d-PGJ2 inhibits endothelial cell apoptosis through, at least in part, c-IAP1 protein stabilization. This mechanism might be involved in the antiapoptotic effect of laminar shear stress.

Maternal Anti-HPA-1a Antibodies Increase Endothelial Cell Apoptosis and Permeability

2021 ◽  
pp. 1-9
Author(s):  
Rima Dardik ◽  
Ophira Salomon
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Intracranial Hemorrhage ◽  
Cell Apoptosis ◽  
Endothelial Damage ◽  
Αvβ3 Integrin ◽  
Endothelial Cell Apoptosis ◽  
Vascular Beds ◽  
Alloimmune Thrombocytopenia

Intracranial hemorrhage (ICH) associated with fetal/neonatal alloimmune thrombocytopenia (FNAIT) is attributed mainly to endothelial damage caused by binding of maternal anti-HPA-1a antibodies to the αvβ3 integrin on endothelial cells (ECs). We examined the effect of anti-HPA-1a antibodies on EC function using 2 EC lines from different vascular beds, HMVEC of dermal origin and hCMEC/D3 of cerebral origin. Anti-HPA-1a sera significantly increased apoptosis in both HMVEC and hCMEC/D3 cells and permeability in hCMEC/D3 cells only. This increase in both apoptosis and permeability was significantly inhibited by a monoclonal anti-β3 antibody (SZ21) binding to the HPA-1a epitope. Our results indicate that (1) maternal anti-HPA-1a antibodies impair EC function by increasing apoptosis and permeability and (2) ECs from different vascular beds vary in their susceptibility to pathological effects elicited by maternal anti-HPA-1a antibodies on EC permeability. Examination of maternal anti-HPA-1a antibodies for their effect on EC permeability may predict potential ICH associated with FNAIT.

scholarly journals LncRNA LUADT1 sponges miR-195 to prevent cardiac endothelial cell apoptosis in sepsis

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Zhimin Zhang ◽  
Mingzhu Lv ◽  
Xiang Wang ◽  
Zheng Zhao ◽  
Daolong Jiang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Critical Role ◽  
Potential Interaction ◽  
Luciferase Reporter ◽  
Endothelial Cell Apoptosis ◽  
Luciferase Activity Assay ◽  
Apoptosis Related Protein

Abstract Background The oncogenic role of the newly identified lncRNA LUADT1 has been revealed in lung adenocarcinoma. It was reported that LUADT1 plays a critical role in multiple human diseases. This study was carried out to investigate the role of LUADT1 in sepsis. Methods Sixty patients with sepsis and sixty healthy volunteers were recruited for this study. Plasma samples were collected from all participants. Human primary coronary artery endothelial cells were also used in this study. The expression of Pim-1, miR-195 and LUADT1 were detected by RT-qPCR. The interaction between miR-195 and LUADT1 was determined by overexpression experiments and luciferase activity assay. Cell apoptosis was detected by flow cytometry. The expression of apoptosis-related protein was detected by Western blotting. Results Bioinformatics analysis revealed the potential interaction between LUADT1 and miR-195, which was confirmed by dual luciferase reporter assay. LUADT1 was downregulated in patients with sepsis. Moreover, LPS treatment downregulated the expression of LUADT1 in primary cardiac endothelial cells. Overexpression of LUADT1 and miR-195 did not affect the expression of each other in primary cardiac endothelial cells. Interestingly, overexpression of LUADT1 was found to upregulate the expression of Pim-1, a target of miR-195. In addition, it was found that overexpression of LUADT1 and Pim-1 reduced the enhancement effects of miR-195 on LPS-induced cardiac endothelial cell apoptosis. Conclusion In summary, LUADT1 may protect cardiac endothelial cells against apoptosis in sepsis by regulating the miR-195/Pim-1 axis.

Epigallocatechin Gallate Reduces Homocysteine-Caused Oxidative Damages through Modulation SIRT1/AMPK Pathway in Endothelial Cells

2020 ◽  
pp. 1-17
Author(s):  
Pei-Ying Pai ◽  
Wan-Ching Chou ◽  
Shih-Hung Chan ◽  
Shu-Yih Wu ◽  
Hsiu-I Chen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Protein Kinase ◽  
Cell Apoptosis ◽  
Pathological Condition ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Epigallocatechin Gallate ◽  
Sirtuin 1 ◽  
Ros Generation ◽  
Endothelial Cell Apoptosis

Elevated plasma concentration of total homocysteine is a pathological condition that causes vascular endothelial injury and subsequently leads to the progression of endothelial apoptosis in atherosclerosis. Epigallocatechin gallate (EGCG), a well-known anti-oxidant in green tea, has been reported with benefits on metabolic and cardiovascular diseases. This study aimed to explore that EGCG ameliorates homocysteine-induced endothelial cell apoptosis through enhancing the sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) survival signaling pathway. Human umbilical endothelial cells were treated with homocysteine in the presence or absence of EGCG. We found that EGCG significantly increased the activities of SIRT1 and AMPK. EGCG diminished homocysteine-mediated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation by inhibiting protein kinase C activation as well as reactive oxygen species (ROS) generation and recovered the activity of the endogenous antioxidant enzyme, superoxidase dismutase (SOD). Besides, EGCG also restores homocysteine-mediated dephosphorylation of Akt and decreases endothelial NO synthase (eNOS) expression. Furthermore, EGCG ameliorates homocysteine-activated pro-apoptotic events. The present study shows that EGCG prevents homocysteine-induced endothelial cell apoptosis via enhancing SIRT1/AMPK as well as Akt/eNOS signaling pathways. Results from this study indicated that EGCG might have some benefits for hyperhomocysteinemia.

Cytosolic phospholipase A2-α is an early apoptotic activator in PEDF-induced endothelial cell apoptosis

2009 ◽  
Vol 296 (2) ◽  
pp. C273-C284 ◽  
Author(s):  
Tsung-Chuan Ho ◽  
Show-Li Chen ◽  
Yuh-Cheng Yang ◽  
Tzu-Hsiu Lo ◽  
Jui-Wen Hsieh ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
P38 Mapk ◽  
Cell Apoptosis ◽  
Nuclear Translocation ◽  
Mitogen Activated Protein Kinase ◽  
Endothelial Cell Apoptosis ◽  
P53 Expression ◽  
Ppar Γ

Pigment epithelium-derived factor (PEDF) is an intrinsic antiangiogenic factor and a potential therapeutic agent. Previously, we discovered the mechanism of PEDF-induced apoptosis of human umbilical vein endothelial cells (HUVECs) as sequential induction/activation of p38 mitogen-activated protein kinase (MAPK), peroxisome proliferator-activated receptor gamma (PPAR-γ), and p53. In the present study, we investigated the signaling role of cytosolic calcium-dependent phospholipase A2-α (cPLA2-α) to bridge p38 MAPK and PPAR-γ activation. PEDF induced cPLA2-α activation in HUVECs and in endothelial cells in chemical burn-induced vessels on mouse cornea. The cPLA2-α activation is evident from the phosphorylation and nuclear translocation of cPLA2-α as well as arachidonic acid release and the cleavage of PED6, a synthetic PLA2 substrate. Such activation can be abolished by p38 MAPK inhibitor. The PEDF-induced PPAR-γ activation, p53 expression, caspase-3 activity, and apoptosis can be abolished by both cPLA2 inhibitor and small interfering RNA targeting cPLA2-α. Our observation not only establishes the signaling role of cPLA2-α but also for the first time demonstrates the sequential activation of p38 MAPK, cPLA2-α, PPAR-γ, and p53 as the mechanism of PEDF-induced endothelial cell apoptosis.

Angiostatin and plasminogen share binding to endothelial cell surface actin

2005 ◽  
Vol 83 (1) ◽  
pp. 28-35 ◽  
Author(s):  
A K Dudani ◽  
M Ben-Tchavtchavadze ◽  
S Porter ◽  
E Tackaberry
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Dependent Manner ◽  
Proteolytic Fragment ◽  
Binding Motifs ◽  
Fluorescence Studies ◽  
Endothelial Cell Surface ◽  
Dose Dependent ◽  
Dependent Processes

Previous studies from this laboratory have demonstrated that plasminogen binds to endothelial cell surface-associated actin via its kringles in a dose-dependent and specific manner. The purpose of this study was to determine whether angiostatin, a proteolytic fragment of plasminogen, shares binding properties with plasminogen. Our results indicated that like plasminogen, angiostatin bound to actin in a time-, concentration-, and kringle-dependent manner. Furthermore, this binding was significantly inhibited by excess plasminogen, suggesting that both proteins shared binding motifs on the actin molecule. Fluorescence studies demonstrated that angiostatin bound to intact endothelial cells through its kringles, and this binding was also inhibited by plasminogen but not by unrelated proteins. Ligand blot analyses on endothelial cell lysates indicated that angiostatin interacted with a 42 kDa protein, which was identified as actin. Furthermore, an anti-actin antibody inhibited binding of angiostatin to endothelial cells by approximately 25%. These results suggest that angiostatin and plasminogen share binding to endothelial cell surface actin and, therefore, that angiostatin has the potential to inhibit plasmin-dependent processes such as cell migration–movement.Key words: plasminogen, angiostatin, endothelial cells, actin.

scholarly journals Atherosclerosis-Associated Endothelial Cell Apoptosis by MiR-429-Mediated Down Regulation of Bcl-2

2015 ◽  
Vol 37 (4) ◽  
pp. 1421-1430 ◽  
Author(s):  
Tao Zhang ◽  
Feng Tian ◽  
Jing Wang ◽  
Jing Jing ◽  
Shan-Shan Zhou ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Cell Injury ◽  
Luciferase Reporter ◽  
Lower Percentage ◽  
Endothelial Cell Apoptosis ◽  
Down Regulation ◽  
Bioinformatics Analyses

Background/Aims: Endothelial cell injury and subsequent apoptosis play a key role in the development and pathogenesis of atherosclerosis, which is hallmarked by dysregulated lipid homeostasis, aberrant immunity and inflammation, and plaque-instability-associated coronary occlusion. Nevertheless, our understanding of the mechanisms underlying endothelial cell apoptosis is still limited. MicroRNA-429 (miR-29) is a known cancer suppressor that promotes cancer cell apoptosis. However, it is unknown whether miR-429 may be involved in the development of atherosclerosis through similar mechanisms. We addressed these questions in the current study. Methods: We examined the levels of endothelial cell apoptosis in ApoE (-/-) mice suppled with high-fat diet (HFD), a mouse model for atherosclerosis (simplified as HFD mice). We analyzed the levels of anti-apoptotic protein Bcl-2 and the levels of miR-429 in the purified CD31+ endothelial cells from mouse aorta. Prediction of the binding between miR-429 and 3'-UTR of Bcl-2 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. The effects of miR-429 were further analyzed in an in vitro model using oxidized low-density lipoprotein (ox-LDL)-treated human aortic endothelial cells (HAECs). Results: HFD mice developed atherosclerosis in 12 weeks, while the control ApoE (-/-) mice that had received normal diet (simplified as NOR mice) did not. HFD mice had significantly lower percentage of endothelial cells and significantly higher percentage of mesenchymal cells in the aorta than NOR mice. Significantly higher levels of endothelial cell apoptosis were detected in HFD mice, resulting from decreases in Bcl-2 protein, but not mRNA. The decreases in Bcl-2 in endothelial cells were due to increased levels of miR-429, which suppressed the translation of Bcl-2 mRNA via 3'-UTR binding. These in vivo findings were reproduced in vitro on ox-LDL-treated HAECs. Conclusion: Atherosclerosis-associated endothelial cell apoptosis may result from down regulation of Bcl-2, through increased miR-429 that binds and suppresses translation of Bcl-2 mRNA.

Sign in / Sign up

Export Citation Format

Share Document