CD95 engagement induces disseminated endothelial cell apoptosis in vivo: immunopathologic implications

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2940-2947 ◽  
Author(s):  
Anne Janin ◽  
Christophe Deschaumes ◽  
Marjan Daneshpouy ◽  
Jérôme Estaquier ◽  
Juliette Micic-Polianski ◽  
...  

Abstract Fas (CD95) is a death receptor involved in apoptosis induction on engagement by Fas ligand (CD95L). Although CD95L-mediated apoptosis has been proposed as a pathogenic mechanism in a wide range of diseases, including graft-versus-host disease, systemic CD95 engagement in mice by agonistic CD95-specific antibodies or by soluble multimeric CD95L (smCD95L), though lethal, has been reported to cause apoptosis only in a limited range of cell types, that is, hepatocytes, hepatic sinusoidal endothelial cells, and lymphocytes. Another member of the tumor necrosis factor (TNF)/CD95L family, TNF-α, induces disseminated vascular endothelial cell apoptosis, which precedes apoptosis of other cell types and lethal multiorgan failure. Here we show that systemic CD95 engagement in vivo by agonistic CD95-specific antibody or smCD95L causes rapid, extensive, and disseminated endothelial cell apoptosis throughout the body, by a mechanism that does not depend on TNF-α. Disseminated endothelial cell apoptosis was also the first detectable lesion in a murine model of acute tissue damage induced by systemic transfer of allogeneic lymphocytes and did not occur when allogeneic lymphocytes were from CD95L-defective mice. Both vascular and additional tissue lesions induced by agonistic CD95-specific antibody, smCD95L, or allogeneic lymphocytes were prevented by treatment with an inhibitor of caspase-8, the upstream caspase coupled to CD95 death signaling. Vascular lesions are likely to play an important role in the pathogenesis of allogeneic immune responses and of other diseases involving circulating CD95L-expressing cells or smCD95L, and the prevention of CD95-mediated death signaling in endothelial cells may have therapeutic implications in these diseases.

2007 ◽  
Vol 26 (7) ◽  
pp. 595-602 ◽  
Author(s):  
R. Demiralay ◽  
N. Gürsan ◽  
H. Erdem

This study investigated the frequency of apoptosis in rat pulmonary artery endothelial cells after intraperitoneal nicotine injection, examining the roles of the inflammatory markers myeloperoxidase (MPO), tumour necrosis factor alpha (TNF-α ), and vascular endothelial growth factor (VEGF) in nicotine-induced vascular damage and the protective effects of two known antioxidant agents, N-acetylcysteine (NAC) and vitamin E. Female Wistar rats were divided into four groups, each composed of nine rats: negative control group, positive control group, NACtreated group (500 mg/kg), and vitamin E-treated group (500 mg/kg). Nicotine was intraperitoneally injected at a dosage of 0.6 mg/kg for 21 days. Following nicotine injection, the antioxidants were administered orally; treatment was continued until the rats were killed. Lung tissue samples were stained with hematoxylin-eosin (H&E) for histopathological assessments. Apoptosis level in endothelial cells was determined by using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick endlabelling) method. Staining of cytoplasmic TNF-α and VEGF in endothelial cells, and perivascular MPO activity were evaluated by immunohistochemistry. The treatments with NAC and vitamin E significantly reduced the rate of nicotine-induced endothelial cell apoptosis. NAC and vitamin E significantly reduced the increases in the local production of TNF-α and VEGF, and perivascular MPO activity. This findings suggest that NAC can be as effective as vitamin E in protecting against nicotine-induced endothelial cell apoptosis. Human & Experimental Toxicology (2007) 26: 595—602.


Author(s):  
Ji-Xiong Chen ◽  
Xiao-Yan Huang ◽  
Ping Wang ◽  
Wen-Ting Lin ◽  
Wen-Xing Xu ◽  
...  

This study aimed to investigate the effects of arachidonic acid metabolite epoxyeicosatrienoic acid (EETs) in the apoptosis of endothelial cells induced by tumor necrosis factor-alpha (TNF-α). After human umbilical vein endothelial cells were cultured, TNF-α/ActD, 14, 15-EET, and HMR-1098 were added, respectively, into the culture medium. The apoptosis level of endothelial cells was detected by flow cytometry. After TNF-α/ActD induced endothelial cell apoptosis, flow cytometry staining showed that endothelial cell apoptosis increased significantly, and the apoptotic cells were significantly reduced after the addition of 14, 15-EET. However, the apoptotic cells significantly increased after the addition of HMR-1098. Western Blot results showed that the phosphorylation levels of LC3-II and AMPK were increased after TNF-α/ActD induction, and the increase was noticeable after the addition of 14, 15-EET. However, the phosphorylation levels of LC3-II and AMPK significantly decreased after the addition of HMR-1098. The activity of Caspase-8 and -9 decreased significantly after the addition of 14, 15-EET but increased after the addition of HMR-1098. Arachidonic acid can inhibit TNF-α induced endothelial cell apoptosis by upregulating autophagy.


2009 ◽  
Vol 87 (3) ◽  
pp. 221-229 ◽  
Author(s):  
Fang Wang ◽  
Hui-min Liu ◽  
Michael G. Irwin ◽  
Zhong-yuan Xia ◽  
Zhiyong Huang ◽  
...  

The circulatory inflammatory cytokine tumor necrosis factor alpha (TNF-α) is increased in pathologic conditions that initiate or exacerbate vascular endothelial injury, such as diabetes. Protein kinase C (PKC) has been shown to play a critical role in TNF-α-induced human endothelial cell apoptosis. However, the relative roles played by specific isoforms of PKC in TNF-α-induced human endothelial cell apoptosis have not been addressed. We investigated the effects of a selective PKCβ2 inhibitor (CGP53353) on TNF-α-induced apoptosis in human vascular endothelial cells (cell line ECV304) and on the production of reactive oxygen species and nitric oxide, and compared its effects with rottlerin, a reagent that has been shown to reduce PKCδ protein levels. Cultured human vascular endothelial cells (ECV304) were treated for 24 h with one of 4 regimes: 40 ng/mL TNF-α alone (TNF-α), TNF-α with 10 µmol/L rottlerin (T+rottlerin), TNF-α with 1 µmol/L CGP53353 (T+CGP), or untreated (control). Cell viability was measured by MTT assay, and cell apoptosis was assessed by flow cytometry. TNF-α-induced endothelial cell apoptosis was associated with dramatic increases in production of intracellular hydrogen peroxide (approximately 20 times greater than control) and superoxide (approximately 16 times greater than control), as measured by dichlorofluorescein and dihydroethidium fluorescent staining, respectively. This increase was accompanied by reduced activity of superoxide dismutase and glutathione peroxidase and, subsequently, an increase in the lipid peroxidation product malondialdehyde. CGP53353, but not rottlerin, abolished or attenuated all these changes. We conclude that PKCβ2 plays a major role in TNF-α-induced human vascular endothelial cell apoptosis.


2002 ◽  
Vol 367 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Jahangir KABIR ◽  
Melvin LOBO ◽  
Ian ZACHARY

The survival of endothelial cells is dependent on interactions between the matrix and integrins mediated through focal adhesions. Focal adhesion kinase (FAK) is thought to play a key role in maintaining focal adhesion function and cell survival, whereas caspase-mediated FAK proteolysis is implicated in focal adhesion disassembly during apoptosis. We examined the relationship between changes in FAK phosphorylation and proteolysis during apoptosis of primary porcine aortic endothelial cells (PAEC) induced by staurosporine, a widely used apoptogenic agent in diverse cell types. Staurosporine-induced PAEC apoptosis was detected after 1h and was preceded by disruption and loss of FAK localization to focal adhesions within a few minutes, whereas staurosporine-induced cleavage of FAK occurred only after 8—24h. Staurosporine induced a very rapid dephosphorylation of FAK at Tyr861 and Tyr397 and caused dissociation of phosphorylated FAK from focal adhesions as early as 30s. The effect of staurosporine was very potent with striking inhibition of Tyr861 and Tyr397 phosphorylation and focal adhesion disruption occurring in the range 10—100nM. Selective inhibition of a known target of staurosporine, protein kinase C, using GF109203X, and of phosphoinositide 3′-kinase using wortmannin, did not reduce FAK tyrosine phosphorylation at Tyr861 and Tyr397, or cause disruption of focal adhesions. Cycloheximide, the protein synthesis inhibitor, induced PAEC apoptosis more slowly than staurosporine, but did not induce FAK dephosphorylation or rapid focal adhesion disruption, and instead caused a slower loss of focal adhesions and a marked increase in FAK proteolysis. These studies show that FAK dephosphorylation and focal adhesion disassembly are very early events mediating the onset of staurosporine-induced endothelial cell apoptosis and are dissociated from FAK proteolysis. Cycloheximide induces apoptosis through a pathway involving FAK proteolysis without dephosphorylation.


2021 ◽  
pp. 1-9
Author(s):  
Rima Dardik ◽  
Ophira Salomon

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.


2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Zhimin Zhang ◽  
Mingzhu Lv ◽  
Xiang Wang ◽  
Zheng Zhao ◽  
Daolong Jiang ◽  
...  

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.


Author(s):  
Pei-Ying Pai ◽  
Wan-Ching Chou ◽  
Shih-Hung Chan ◽  
Shu-Yih Wu ◽  
Hsiu-I Chen ◽  
...  

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.


2009 ◽  
Vol 296 (2) ◽  
pp. C273-C284 ◽  
Author(s):  
Tsung-Chuan Ho ◽  
Show-Li Chen ◽  
Yuh-Cheng Yang ◽  
Tzu-Hsiu Lo ◽  
Jui-Wen Hsieh ◽  
...  

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.


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