scholarly journals DAXX mediates high phosphate-induced endothelial cell apoptosis in vitro through activating ERK signaling

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.

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 ◽  
Author(s):  
Mangyuan Wang ◽  
Fen Liu ◽  
Binbin Fang ◽  
Qiang Huo ◽  
Yining Yang

Abstract Backgrounds: Vascular endothelial cell apoptosis is the first risk factor of atherosclerosis (AS), and it can be induced by high doses of glucose and palmitic acid (PA). The purpose of our study is to use a new generation of high-throughput transcription factors (TFs) detecting method to identify novel candidate key TFs involved in PA-induced vascular endothelial cell apoptosis.Methods: Human umbilical vein endothelial cells (HUVECs) were treated with 0µM PA (control group), 250µM PA (group 1), or 500µM PA (group 2). Candidate TFs among the three groups were determined by significant changes according to t-test, and pathway enrichment, western blot (WB) and RT-qPCR were then performed.Results: Fifty-one TFs showing with significant p value were identified, and 24 TFs with significant p value plus fold change > 2 and with dose-dependence were identified with 12 TFs biologically validated in former studies. Two of the remaining 12 novel TFs, v-maf musculoaponeurotic fibrosarcoma oncogene family protein G (MAFG) and v-maf musculoaponeurotic fibrosarcoma oncogene family protein F (MAFF), were matched to AS known signalling pathways and were validated by WB and RT-qPCR in our study.Conclusions: We identified MAFG and MAFF as novel candidate key TFs in vascular endothelial cell apoptosis, which is the key initial process of AS.


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.


2010 ◽  
Vol 299 (3) ◽  
pp. E351-E363 ◽  
Author(s):  
Shu Liu ◽  
Hua Shen ◽  
Ming Xu ◽  
Ou Liu ◽  
Limin Zhao ◽  
...  

Atherosclerosis is the most common cause of cardiovascular diseases in the world. Although the development of atherosclerosis appears to be the result of multiple maladaptive pathways, a particularly important factor in the pathogenesis of atherosclerosis is oxidized low-density lipoprotein (ox-LDL), which contributes to endothelial damage. Data from our laboratory and others show that follistatin-related protein (FRP), which is expressed in the vasculature, has cardioprotective effects, suggesting that loss of FRP protection might play a role in the development of atherosclerosis. In the present study, we determined whether FRP overexpression protects against endothelial cell (EC) damage, an intermediate end point for atherosclerosis. We bred apoE-knockout (apoE−/−) mice that were FRP+ transgenic (they overexpressed FRP). We compared them with control mice (their littermates). Human umbilical vein endothelial cells (HUVECs) were isolated and treated with ox-LDL and recombinant FRP. FRP-induced signal transduction and Bcl-2 mRNA and protein stability were analyzed. After 16 wk, apoE−/− FRP+ mice had significantly fewer apoptotic ECs than controls. In vitro experiments showed that the effect of FRP on EC apoptosis was mediated by upregulation of expression of the antiapoptotic protein Bcl-2. In HUVECs, FRP upregulated Bcl-2 transcription via a PI3K-Akt-NF-κB pathway. We conclude that FRP overexpression maintains EC viability by preventing apoptosis via Bcl-2 upregulation. FRP may be a novel therapeutic target for the prevention and treatment of vascular EC injury and of atherosclerosis.


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.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Krishna K Singh ◽  
Praphulla C Shukla ◽  
Fina Lovren ◽  
Yi Pan ◽  
Paul Jurasz ◽  
...  

INTRODUCTION: Endothelial cell apoptosis, in response to inflammatory, ischemic and hypoxic stressors, has been identified as an essential target for therapies aimed at improving graft patency. BRCA1 is a tumor suppressor gene which functions primarily to promote DNA repair, and afford protection against various genotoxic stimuli, including immunosuppressant and chemotherapeutic regimens often employed post-transplantation. We hypothesized that BRCA1 is a novel target to limit inflammation-induced endothelial cell apoptosis and to restore endothelial function. METHODS AND RESULTS: In the first series of studies, we used a gain-of-function approach by adenoviral BRCA1 overexpression in human umbilical vein endothelial cells (HUVECs). Ad-BRCA1-expressing HUVECs exhibited profound protection against TNFα (20 ng/ml)-induced apoptosis, as assessed by flow cytometry, DNA laddering, COMET assay and cleaved procaspase 3 (P < 0.01). This response was mediated by complete prevention of TNFα-induced increases in endothelial ROS production (P < 0.001, vs. Ad-BRCA1). Furthermore, Ad-BRCA1 overexpression prevented TNFα-induced reduction in key indices of endothelial function, namely capillary-like tube formation (P < 0.01) and cell migration (P < 0.01). The protective effects of BRCA1 were not mediated by changes in total or phosphorylated p53 (P = 0.1) but were associated with a significant 6-fold upregulation in eNOS (P < 0.05). A loss-of-function strategy with BRCA1 gene silencing reversed the effects on endothelial apoptosis, ROS production and eNOS phosporylation. CONCLUSIONS: BRCA1 protects endothelial cells against inflammation-induced apoptosis, through a mechanism that involves up-regulation of eNOS and reduced ROS production, and is a novel candidate gene to limit aberrant vascular remodeling. These data also suggest that patients with BRCA1 mutations or cancer syndromes may be at an exaggerated risk of native and transplant atherosclerosis and graft dysfunction, particularly in the setting of DNA damaging immunosuppressants.


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.


2012 ◽  
Vol 302 (7) ◽  
pp. F884-F894 ◽  
Author(s):  
Nidia Maritza Hernandez ◽  
Anna Casselbrant ◽  
Meghnad Joshi ◽  
Bengt R. Johansson ◽  
Suchitra Sumitran-Holgersson

Anti-endothelial cell antibodies (AECA) have been reported to cause endothelial dysfunction, but their clinical importance for tissue-specific endothelial cells is not clear. We hypothesized that AECA reactive with human kidney endothelial cells (HKEC) may cause renal endothelial dysfunction in patients with chronic kidney diseases. We report that a higher fraction (56%) of end-stage renal disease (ESRD) patients than healthy controls (5%) have AECA reactive against kidney endothelial cells ( P <0.001). The presence of antibodies was associated with female gender ( P < 0.001), systolic hypertension ( P < 0.01), and elevated TNF-α ( P < 0.05). These antibodies markedly decrease expression of both adherens and tight junction proteins VE-cadherin, claudin-1, and zonula occludens-1 and provoked a rapid increase in cytosolic free Ca2+and rearrangement of actin filaments in HKEC compared with controls. This was followed by an enhancement in protein flux and phosphorylation of VE-cadherin, events associated with augmented endothelial cell permeability. Additionally, kidney biopsies from ESRD patients with AECA but not controls demonstrated a marked decrease in adherens and tight junctions in glomerular endothelium, confirming our in vitro data. In summary, our data demonstrate a causal link between AECA and their capacity to induce alterations in glomerular vascular permeability.


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