Oxidized low-density lipoprotein (oxLDL) triggers hypoxia-inducible factor-1α (HIF-1α) accumulation via redox-dependent mechanisms

Blood ◽  
2003 ◽  
Vol 101 (12) ◽  
pp. 4847-4849 ◽  
Author(s):  
Vladimir A. Shatrov ◽  
Vadim V. Sumbayev ◽  
Jie Zhou ◽  
Bernhard Brüne

Abstract Oxidized low-density lipoprotein (oxLDL) and macrophages play a central role in atherosclerosis. Here, we obtained evidence that oxLDL induced hypoxia-inducible factor-1α (HIF-1α) protein accumulation in human macrophages (Mono-Mac-6) under normoxia. HIF-1α accumulation was attenuated by pretreatment with the antioxidant N-acetyl-L-cysteine (NAC), the nitric oxide (NO) donor S-nitrosoglutathione (GSNO), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors such as diphenyleniodonium (DPI) or 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), thus implicating the contribution of oxLDL-generated reactive oxygen species (ROS). Whereas oxLDL did not modulate HIF-1α mRNA levels, experiments with cycloheximide pointed to a translational mechanism in oxLDL action. HIF-1–dependent luciferase reporter gene analysis underscored HIF-1 transactivation. Our results indicate that oxLDL induced HIF-1α accumulation and HIF-1–dependent reporter gene activation in human macrophages via a redox-mediated pathway. This finding may suggest a role of HIF-1 in atherosclerosis and oxLDL-induced pathogenesis.

2008 ◽  
Vol 7 (8) ◽  
pp. 3572-3582 ◽  
Author(s):  
Annabelle Dupont ◽  
Maggy Chwastyniak ◽  
Olivia Beseme ◽  
Anne-Laure Guihot ◽  
Hervé Drobecq ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaojuan Wang ◽  
Ming Bai

Abstract Background Atherosclerosis (AS) is a chronic inflammatory disorder. The aim of our study was to explore the role of circular RNA (circRNA) transmembrane 7 superfamily member 3 (circTM7SF3) in AS progression. Methods Experiments were conducted using oxidized low-density lipoprotein (ox-LDL)-induced THP-1-derived macrophages and differentiated human monocyte-derived macrophages (hMDMs). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circTM7SF3, its linear form TM7SF3, microRNA-206 (miR-206) and aspartyl (asparaginyl) β-hydroxylase (ASPH) messenger RNA (mRNA). Cell viability and apoptosis were examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Cell inflammation was analyzed by measuring the production of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) using enzyme-linked immunosorbent assay (ELISA) kits. Cell oxidative stress was assessed through analyzing the levels of oxidative stress markers using their corresponding commercial kits. Dual-luciferase reporter assay and RNA-pull down assay were used to confirm the interaction between miR-206 and circTM7SF3 or ASPH. The protein level of ASPH was examined by Western blot assay. Results CircTM7SF3 level was markedly increased in the serum samples of AS patients and ox-LDL-induced THP-1-derived macrophages compared with their matching counterparts. ox-LDL induced-damage in THP-1 cells was partly attenuated by the interference of circTM7SF3. MiR-206 was a downstream molecular target of circTM7SF3. Si-circTM7SF3-mediated effects in ox-LDL-induced THP-1-derived macrophages were partly ameliorated by the addition of anti-miR-206. MiR-206 directly interacted with ASPH mRNA. CircTM7SF3 silencing reduced the expression of ASPH partly through up-regulating miR-206 in THP-1-derived macrophages. ASPH overexpression partly counteracted the effects induced by miR-206 overexpression in ox-LDL-induced THP-1-derived macrophages. Conclusion CircTM7SF3 contributed to ox-LDL-induced injury in AS cell model through up-regulating the expression of ASPH via targeting miR-206.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Tomohide Takaya ◽  
Tatsuya Morimoto ◽  
Yoichi Sunagawa ◽  
Hiromichi Wada ◽  
Teruhisa Kawamura ◽  
...  

Lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1) was originally identified as an endothelial receptor for oxidized LDL, and now is recognized as a multi-ligand receptor. LOX-1 expression in cardiomyocytes can be induced by oxidative stress and various hormonal stimuli. Activation of the LOX-1 pathway in cardiomyocytes induces apoptosis in vitro and deteriorates ischemia-reperfusion injury in vivo . However the role of LOX-1 in chronic heart failure is unknown. We examined the left ventricular (LV) expression of LOX-1 in a salt-sensitive Dahl (DS) rat model of hypertension. Compared with control salt-resistant Dahl (DR) rats, a high-salt diet, started at the age of 6 weeks, induced marked hypertension and apparent concentric LV hypertrophy on echocardiography in DS rats. The LV hypertrophy was moderate at the age of 11 weeks and marked at 18 weeks. The LV systolic function was preserved at 11 weeks, and decreased at 18 weeks. Quantitative real-time PCR revealed a 4.7-fold increase in LV levels of LOX-1 mRNA in DS rats compared with DR rats at 11 weeks, and a 32-fold increase at 18 weeks. The LV LOX-1 mRNA levels were significantly correlated with the LV end-systolic dimension (R=0.640, p=0.0002), and LV posterior wall thickness (R=0.555, p=0.0022), as well as the LV/body weight ratio (R=0.647, p=0.0002), and systolic blood pressure (R=0.751, p<0.0001). LOX-1 levels were also connected with an increase in LV mRNA levels of heme oxygenase-1 (R=0.692, p<0.0001), a marker of oxidative stress. Importantly, LOX-1 levels were strongly associated with a decrease in the LV ejection fraction (R=0.774, p<0.0001) and an increase in mRNA levels of BNP (R=0.814, p<0.0001), a representative marker of LV wall stress and heart failure. Immunohistochemistry demonstrated LOX-1 expression in cardiomyocytes as well as vessel walls of both DS and DR rat hearts. However, expression in cardiomyocytes was greater in DS than in DR. These findings demonstrate that LV cardiomyocyte expression of LOX-1 is markedly increased in proportion to the extent of heart failure and possibly involved in the deterioration of systolic function in the DS rat model of hypertension.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Haiyan Shan ◽  
Dawei Guo ◽  
Siyang Zhang ◽  
Huimeng Qi ◽  
Shen Liu ◽  
...  

Abstract Background Plenty of long non-coding RNAs (lncRNAs) play vital roles in the progression of atherosclerosis. Small nucleolar RNA host gene 6 (SNHG6) is a well known lncRNA that is aberrantly high expressed in atherosclerosis patients. However, its function and basic mechanism in atherosclerosis events have not been well clarified. Methods The expression patterns of SNHG6, miR-135a-5p, ROCK1 and ROCK2 in clinical samples and cells were detected by RT-qPCR assays. Cell Counting Kit-8 (CCK-8), flow cytometry assays, ELISA and reactive oxygen species (ROS) and malondialdehyde (MDA) detection, were performed to assess cell viability, apoptosis, inflammation and oxidative stress, respectively. Western blot analysis was carried out to examine the protein levels of Bax, Bcl-2, and SNHG6. Luciferase reporter and RIP assays were used to confirm the true interaction between SNHG6 and miR-135a-5p, or miR-135a-5p and ROCK. Results The levels of SNHG6, ROCK1 and ROCK2 were notably increased and miR-135a-5p was decreased in atherosclerosis patients and oxidized low-density lipoprotein (ox-LDL)-treated HUVECs. Knockdown of SNHG6 alleviated ox-LDL-induced injury of HUVECs, while this effect was partly reversed by miR-135a-5p inhibitor. Moreover, overexpression of ROCKs aggravated miR-135a-5p-alleviated atherosclerosis cell injury. SNHG6 contributed to ROCK expression through sequestering miR-135a-5p as a molecular sponge. Conclusion SNHG6 functions as a promoter in atherosclerosis events by targeting miR-135a-5p/ROCK axis in ox-LDL-stimulated HUVECs. This finding will help to develop a novel therapeutic strategy for atherosclerosis.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Jia Ni ◽  
Zhen Huang ◽  
Dan Wang

Abstract Background Although lncRNA TP73-AS1 has been shown to play important roles in various human diseases, its function in atherosclerosis (AS) remains unclear. Methods Human aortic endothelial cells (HAECs) were treated with 50 μg/ml oxidized low-density lipoprotein (ox-LDL) to establish an atherosclerotic cell model. The expression of TP73-AS1, miR-654-3p and AKT3 was detected by qRT-PCR. Cell functions were evaluated CCK-8 assay and flow cytometry. The protein levels of apoptosis-related proteins were evaluated by western blot. The binding relationship among TP73-AS1, miR-654-3p and AKT3 was determined by bioinformatics analysis and luciferase reporter assay. Results TP73-AS1 was upregulated and miR-654-3p was downregulated in ox-LDL treated HAECs. TP73-AS1 silencing and miR-654-3p mimics decreased the viability and inhibited apoptosis of ox-LDL treated HAECs, decreased the expression levels of c-caspase-9, c-caspase-3 and Bax, and increased Bcl-2 expression. In addition, miR-654-3p inhibitor significantly reversed the inhibitory effects of si-TP73-AS1 on cell viability and apoptosis. TP73-AS1 could positively regulate AKT3 through directly sponging miR-654-3p. Conclusion TP73-AS1 promoted apoptosis of ox-LDL stimulated endothelial cells by targeting the miR-654-3p/AKT3 axis, suggesting that TP73-AS1 might be a potential target for AS treatment.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chi Zhang ◽  
Liyue Wang ◽  
Ying Shen

Abstract Background Circular RNAs have shown important regulatory roles in cardiovascular diseases, containing atherosclerosis (AS). We intended to explore the role of circ_0004104 in AS using oxidized low-density lipoprotein (ox-LDL)-induced vascular endothelial cells and its associated mechanism. Methods Real-time quantitative polymerase chain reaction and Western blot assay were conducted to analyze RNA levels and protein levels, respectively. Cell viability, apoptosis, angiogenic ability and inflammatory response were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, flow cytometry, capillary-like network formation assay and enzyme-linked immunosorbent assay, respectively. Cell oxidative stress was assessed using commercial kits. Dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA-pull down assay were performed to verify the intermolecular interaction. Results ox-LDL exposure up-regulated the level of circ_0004104 in HUVECs. ox-LDL exposure suppressed cell viability and angiogenic ability whereas promoted the apoptosis, inflammation and oxidative stress of HUVECs partly through up-regulating circ_0004104. MicroRNA-328-3p (miR-328-3p) was confirmed as a target of circ_0004104. MiR-328-3p interference largely reversed circ_0004104 silencing-mediated effects in HUVECs upon ox-LDL exposure. MiR-328-3p interacted with the 3′ untranslated region of tripartite motif 14, and circ_0004104 positively regulated TRIM14 expression by sponging miR-328-3p. TRIM14 overexpression largely overturned miR-328-3p accumulation-induced influences in HUVECs upon ox-LDL exposure. Conclusion Circ_0004104 knockdown attenuated ox-LDL-induced dysfunction in HUVECs via miR-328-3p-mediated regulation of TRIM14.


Sign in / Sign up

Export Citation Format

Share Document