scholarly journals Upregulation of microRNA-876 Induces Endothelial Cell Apoptosis by Suppressing Bcl-Xl in Development of Atherosclerosis

2017 ◽  
Vol 42 (4) ◽  
pp. 1540-1549 ◽  
Author(s):  
Kaicheng Xu ◽  
Peng Liu ◽  
Yue Zhao

Background/Aims: The injury and apoptotic cell death of endothelial cells hallmark the development of atherosclerosis (AS), characterized by dysregulation of lipid homeostasis, immune responses, and formation of coronary plaques. However, the mechanisms underlying the initiation of endothelial cell apoptosis remain ill-defined. Recent evidence suggests a role of microRNAs in the processes of AS-associated endothelial cell apoptosis. Thus, we studied this question in the current study. Methods: AS was developed in ApoE (-/-) mice suppled with high-fat diet (HFD), compared to ApoE (-/-) mice suppled with normal diet (ND). Mouse endothelial cells were isolated from the aortic arch using flow cytometry based on their expression of Pecam-1. Oxidized low-density lipoprotein (ox-LDL) were used to treat human aortic endothelial cells (HAECs) as an in vitro model for AS. Gene expression was quantified by RT-qPCR and protein levels were analyzed by Western blotting. Apoptosis was evaluated by FITC Annexin V Apoptosis essay and by TUNEL staining. Prediction of the binding between miRNAs and 3'-UTR of mRNA from the target gene was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. Results: HFD mice, but not ND mice, developed AS in 12 weeks. Significantly reduced endothelial cell marks and significantly increased mesenchymal cell marks were detected in the aortic arch of the HFD mice, compared to the ND mice. The endothelial cell apoptosis was significantly higher in HFD mice, seemingly due to functional suppression of protein translation of anti-apoptotic Bcl-Xl protein through upregulation of miR-876. Similar results were obtained from in vitro study. Inhibition of miR-876 abolished the effects of ox-LDL-induced apoptotic cell death of HAECs. Conclusion: AS-associated endothelial cell apoptosis may partially result from downregulation of Bcl-Xl, through upregulation of miR-876 that binds and suppresses translation of Bcl-Xl mRNA.

2015 ◽  
Vol 37 (4) ◽  
pp. 1421-1430 ◽  
Author(s):  
Tao Zhang ◽  
Feng Tian ◽  
Jing Wang ◽  
Jing Jing ◽  
Shan-Shan Zhou ◽  
...  

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.


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.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3972-3972
Author(s):  
George T. Roberts ◽  
Muhammad A. Chishti ◽  
Fallah H. Al-Mohanna ◽  
Raafat M. El-Sayed ◽  
Abderezak Bouchama

Abstract Introduction: Ultrastructural evidence of endothelial cell (EC) injury has been associated with diffuse microvascular thrombosis in human heatstroke (HS). In vitro studies have also shown that heat stress accelerates apoptotic cell death. Using a recently described baboon model of heatstroke, we sought to examine pathological changes in the vascular endothelium and whether apoptosis is a mechanism of endothelial cell death. Hypothesis: Major structural vascular endothelium alterations occur in HS and apoptosis is a mechanism of endothelial cell death in HS. Methods: Anesthetized baboons (Papio hamadyras) were heat-stressed in a neonatal incubator maintained at 44 1.5 °C, until rectal temperature attained 42.5°C (moderate heatstroke; n =4) or systolic blood pressure fell to < 90 mm Hg (severe heatstroke n =4). Animals were resuscitated with normal saline and allowed to cool at room temperature. Four sham-heated animals served as control group. Spleen, liver, heart, kidney, gut, lung and adrenal tissue were obtained either by immediate autopsy in non-survivors or after euthanasia at 72-h for survivors. Vascular endothelium ultrastructure was evaluated by transmission electron microscopy (TEM) of ultra-thin tissue sections. Biological activity of EC was determined by light microscopy (LM) using a polyclonal antibody targeting von Willebrand Factor (vWF). Apoptosis was assessed, also in tissue sections, by deoxyuridine triphosphate nick end-labeling (TUNEL) procedure. Results: In heatstroke animals, there were marked EC changes in lungs, spleen, jejunum, kidneys and liver, demonstrated by TEM, as increased cytoplasmic membrane convolutions that included formation of villi projecting into the vessel lumina, and increase in the width of the gaps between ECs. Migration of neutrophils, platelets and erythrocytes through these widened gaps was noted. Weibel-Palade bodies were increased both in size and number in EC of jejunum, lungs and kidneys. This increase correlated with increased endothelial expression of immunologically detectable vWF. TEM also showed that there was increased apoptosis manifested by nuclear chromatin condensation and karyorrhexis and formation of cytoplasmic myelin whorls. Increased EC apoptosis was also observed by TUNEL in the jejunum, lungs, liver and spleen. All these changes were greater in animals with severe HS than in animals with moderate HS, whereas sham heated control animals showed no significant changes. Conclusion: Widespread EC injury with apoptotic cell death is consistent with the hypothesis that the endothelium may play a pathogenic role in heatstroke.


2004 ◽  
Vol 279 (19) ◽  
pp. 20221-20233 ◽  
Author(s):  
Bysani Chandrasekar ◽  
Kirankumar Vemula ◽  
Rama Mohan Surabhi ◽  
Min Li-Weber ◽  
Laurie B. Owen-Schaub ◽  
...  

Endothelial cells are the primary targets of circulating immune and inflammatory mediators. We hypothesize that interleukin-18, a proinflammatory cytokine, induces endothelial cell apoptosis. Human cardiac microvascular endothelial cells (HCMEC) were treated with interleukin (IL) 18. mRNA expression was analyzed by ribonuclease protection assay, protein levels by immunoblotting, and cell death by enzyme-linked immunosorbent assay and fluorescence-activated cell sorter analysis. We also investigated the signal transduction pathways involved in IL-18-mediated cell death. Treatment of HCMEC with IL-18 increases 1) NF-κB DNA binding activity; 2) induces κB-driven luciferase activity; 3) induces IL-1β and TNF-α expression via NF-κB activation; 4) inhibits antiapoptotic Bcl-2 and Bcl-XL; 5) up-regulates proapoptotic Fas, Fas-L, and Bcl-XSexpression; 6) inducesfasand Fas-L promoter activities via NF-κB activation; 7) activates caspases-8, -3, -9, and BID; 8) induces cytochromecrelease into the cytoplasm; 9) inhibits FLIP; and 10) induces HCME cell death by apoptosis as seen by increased annexin V staining and increased levels of mono- and oligonucleosomal fragmented DNA. Whereas overexpression of Bcl-2 significantly attenuated IL-18-induced endothelial cell apoptosis, Bcl-2/Bcl-XLchimeric phosphorothioated 2′-MOE-modified antisense oligonucleotides potentiated the proapoptotic effects of IL-18. Furthermore, caspase-8, IKK-α, and NF-κB p65 knockdown or dominant negative IκB-α and dominant negative IκB-β or kinase dead IKK-β significantly attenuated IL-18-induced HCME cell death. Effects of IL-18 on cell death are direct and are not mediated by intermediaries such as IL-1β, tumor necrosis factor-α, or interferon-γ. Taken together, our results indicate that IL-18 activates both intrinsic and extrinsic proapoptotic signaling pathways, induces endothelial cell death, and thereby may play a role in myocardial inflammation and injury.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9203
Author(s):  
Shu Wang ◽  
Mingyu Wu ◽  
Ling Qin ◽  
Yaxiang Song ◽  
Ai Peng

Backgroud and Purpose Hyperphosphatemia, which is a high inorganic phosphate (Pi) level in the serum, promotes endothelial cells dysfunction and is associated with cardiovascular diseases in patients with chronic kidney diseases (CKD). However, the underlying mechanism of high Pi-induced endothelia cell apoptosis remains unclear. Methods Human umbilical vein endothelial cells (HUVECs) were treated with normal Pi (1.0 mM) and high Pi (3.0 mM), and then cell apoptosis, abnormal gene expression and potential signaling pathway involvement in simulated hyperphosphatemia were examined using flow cytometry, quantitative PCR (qPCR) and western blot analysis. A two-step 5/6 nephrectomy was carried out to induce CKD and biochemical measurements were taken. Results The rat model of CKD revealed that hyperphosphatemia is correlated with an increased death-domain associated protein (DAXX) expression in endothelial cells. In vitro, high Pi increased the mRNA and protein expression level of DAXX in HUVECs, effects that were reversed by additional phosphonoformic acid treatment. Functionally, high Pi resulted in a significantly increased apoptosis in HUVECs, whereas DAXX knockdown markedly repressed high Pi-induced cell apoptosis, indicating that DAXX mediated high Pi-induced endothelial cell apoptosis. High Pi treatment and DAXX overexpression induced the activation of extracellular regulated protein kinases (ERKs), while DAXX knockdown inhibited high Pi-induced ERKs activation. Finally, we demonstrated that DAXX overexpression induced HUVECs apoptosis in the presence of normal Pi, whereas additional treatment with U0126 (a specific ERK inhibitor) reversed that effect. Conclusion Upregulated DAXX promoted high Pi-induced HUVECs apoptosis by activating ERK signaling and indicated that the DAXX/ERK signaling axis may be served as a potential target for CKD therapy.


RSC Advances ◽  
2018 ◽  
Vol 8 (61) ◽  
pp. 35031-35041 ◽  
Author(s):  
Zhi-Qin Liu ◽  
Jing-Jing Du ◽  
Jing-Jing Ren ◽  
Zhi-Yong Zhang ◽  
Xiao-Bo Guo ◽  
...  

The present research represents the first insight into miRNA regulating FOXO1 expression in atherosclerotic endothelial cells.


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.


1994 ◽  
Vol 180 (4) ◽  
pp. 1547-1552 ◽  
Author(s):  
M G Cifone ◽  
R De Maria ◽  
P Roncaioli ◽  
M R Rippo ◽  
M Azuma ◽  
...  

Intracellular pathways leading from membrane receptor engagement to apoptotic cell death are still poorly characterized. We investigated the intracellular signaling generated after cross-linking of CD95 (Fas/Apo-1 antigen), a broadly expressed cell surface receptor whose engagement results in triggering of cellular apoptotic programs. DX2, a new functional anti-CD95 monoclonal antibody was produced by immunizing mice with human CD95-transfected L cells. Crosslinking of CD95 with DX2 resulted in the activation of a sphingomyelinase (SMase) in promyelocytic U937 cells, as well as in other human tumor cell lines and in CD95-transfected murine cells, as demonstrated by induction of in vivo sphingomyelin (SM) hydrolysis and generation of ceramide. Direct in vitro measurement of enzymatic activity within CD95-stimulated U937 cell extracts, using labeled SM vesicles as substrates, showed strong SMase activity, which required pH 5.0 for optimal substrate hydrolysis. Finally, all CD95-sensitive cell lines tested could be induced to undergo apoptosis after exposure to cell-permeant C2-ceramide. These data indicate that CD95 cross-linking induces SM breakdown and ceramide production through an acidic SMase, thus providing the first information regarding early signal generation from CD95, and may be relevant in defining the biochemical nature of intracellular messengers leading to apoptotic cell death.


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