scholarly journals Omega-3 fatty acids differentially reduced expression of neutrophil degranulation-associated proteins in endothelial cells during IL-6 exposure

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S C R Sherratt ◽  
P Libby ◽  
D L Bhatt ◽  
H Dawoud ◽  
T Malinski ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Protein Expression ◽  
Tissue Injury ◽  
Umbilical Vein ◽  
Mitogen Activated Protein Kinase ◽  
Omega 3 ◽  
Private Company ◽  
Epa And Dha ◽  
Neutrophil Degranulation

Abstract Background Neutrophil degranulation contributes to atherogenesis and tissue injury. Mixed omega-3 fatty acid (n3-FA) formulations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have failed to reduce CV events compared to EPA only (REDUCE-IT), but the mechanisms are not understood. Purpose The purpose of this study was to compare the effects of EPA and DHA on expression of proteins linked to neutrophil degranulation in the vascular endothelium in vitro. Methods Human umbilical vein endothelial cells (HUVECs) were pretreated with EPA or DHA at equimolar levels (10 μM) for 2 h, then challenged with IL-6 at 12 ng/ml for 24 h. Proteomic analysis was performed using LC/MS to measure relative protein expression. Only significant (p<0.05) changes between treatment groups >1-fold were analyzed. Results In the Reactome “neutrophil degranulation” pathway, EPA and DHA downregulated 27 and 14 proteins, respectively, (p=9.97E-9 and 5.30E-4, respectively) relative to IL-6 alone. There were 12 protein changes common to both n3-FAs, including heme oxygenase-2 and ferritin light chain. EPA downregulated 15 proteins unlike DHA, including peroxiredoxin-6 and mitogen-activated protein kinase-1 (MAPK1). A combined 21 proteins downregulated by EPA and DHA versus IL-6 were upregulated by IL-6 alone relative to vehicle. EPA also increased expression of Rho-associated protein kinase-1 (ROCK-1), a protein downregulated by IL-6 alone and unaffected by DHA. Conclusions EPA and DHA differentially modulated expression of proteins linked to neutrophil degranulation. The distinct effects of EPA on protein expression may contribute to reduced inflammation in vascular injury compared to DHA. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Amarin Pharma Inc., Elucida Research

scholarly journals Characterization of the biological effects of a novel protein kinase D inhibitor in endothelial cells

2010 ◽  
Vol 429 (3) ◽  
pp. 565-572 ◽  
Author(s):  
Ian M. Evans ◽  
Azadeh Bagherzadeh ◽  
Mark Charles ◽  
Tony Raynham ◽  
Chris Ireson ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Umbilical Vein ◽  
Biological Effects ◽  
Camp Response Element Binding ◽  
Mitogen Activated Protein Kinase ◽  
Protein Kinase D ◽  
Vegf Receptor

VEGF (vascular endothelial growth factor) plays an essential role in angiogenesis during development and in disease largely mediated by signalling events initiated by binding of VEGF to its receptor, VEGFR2 (VEGF receptor 2)/KDR (kinase insert domain receptor). Recent studies indicate that VEGF activates PKD (protein kinase D) in endothelial cells to regulate a variety of cellular functions, including signalling events, proliferation, migration and angiogenesis. To better understand the role of PKD in VEGF-mediated endothelial function, we characterized the effects of a novel pyrazine benzamide PKD inhibitor CRT5 in HUVECs (human umbilical vein endothelial cells). The activity of the isoforms PKD1 and PKD2 were blocked by this inhibitor as indicated by reduced phosphorylation, at Ser916 and Ser876 respectively, after VEGF stimulation. The VEGF-induced phosphorylation of three PKD substrates, histone deacetylase 5, CREB (cAMP-response-element-binding protein) and HSP27 (heat-shock protein 27) at Ser82, was also inhibited by CRT5. In contrast, CRT6, an inactive analogue of CRT5, had no effect on PKD or HSP27 Ser82 phosphorylation. Furthermore, phosphorylation of HSP27 at Ser78, which occurs solely via the p38 MAPK (mitogen-activated protein kinase) pathway, was also unaffected by CRT5. In vitro kinase assays show that CRT5 did not significantly inhibit several PKC isoforms expressed in endothelial cells. CRT5 also decreased VEGF-induced endothelial migration, proliferation and tubulogenesis, similar to effects seen when the cells were transfected with PKD siRNA (small interfering RNA). CRT5, a novel specific PKD inhibitor, will greatly facilitate the study of the role of PKD signalling mechanisms in angiogenesis.

scholarly journals Bacteroides fragilis Enterotoxin Induces Formation of Autophagosomes in Endothelial Cells but Interferes with Fusion with Lysosomes for Complete Autophagic Flux through a Mitogen-Activated Protein Kinase-, AP-1-, and C/EBP Homologous Protein-Dependent Pathway

2017 ◽  
Vol 85 (10) ◽  
Author(s):  
Su Hyuk Ko ◽  
Jong Ik Jeon ◽  
Hyun Soo Myung ◽  
Young-Jeon Kim ◽  
Jung Mogg Kim
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Umbilical Vein ◽  
Bacteroides Fragilis ◽  
Mitogen Activated Protein Kinase ◽  
Mucosal Inflammation ◽  
Autophagic Flux ◽  
Content Type ◽  
Homologous Protein ◽  
Mitogen Activated Protein

ABSTRACT Bacteroides fragilis enterotoxin (BFT), a virulence factor of enterotoxigenic B. fragilis (ETBF), plays an essential role in mucosal inflammation. Although autophagy contributes to the pathogenesis of diverse infectious diseases, little is known about autophagy in ETBF infection. This study was conducted to investigate the role of BFT in the autophagic process in endothelial cells (ECs). Stimulation of human umbilical vein ECs (HUVECs) with BFT increased light chain 3 protein II (LC3-II) conversion from LC3-I and protein expression of p62, Atg5, and Atg12. In addition, BFT-exposed ECs showed increased indices of autophagosomal fusion with lysosomes such as LC3–lysosome-associated protein 2 (LAMP2) colocalization and the percentage of red vesicles monitored by the expression of dual-tagged LC3B. BFT also upregulated expression of C/EBP homologous protein (CHOP), and inhibition of CHOP significantly increased indices of autophagosomal fusion with lysosomes. BFT activated an AP-1 transcription factor, in which suppression of AP-1 activity significantly downregulated CHOP and augmented autophagosomal fusion with lysosomes. Furthermore, suppression of Jun N-terminal protein kinase (JNK) mitogen-activated protein kinase (MAPK) significantly inhibited the AP-1 and CHOP signals, leading to an increase in autophagosomal fusion with lysosomes in BFT-stimulated ECs. These results suggest that BFT induced accumulation of autophagosomes in ECs, but activation of a signaling pathway involving JNK, AP-1, and CHOP may interfere with complete autophagy.

Transient hypoxia induces ERK-dependent anti-apoptotic cell survival in endothelial cells

2010 ◽  
Vol 298 (6) ◽  
pp. C1501-C1509 ◽  
Author(s):  
F. V. Härtel ◽  
M. Holl ◽  
M. Arshad ◽  
M. Aslam ◽  
D. Gündüz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Caspase 3 ◽  
Tissue Injury ◽  
Apoptotic Cell ◽  
Umbilical Vein ◽  
Phosphorylation Site ◽  
Cell Types ◽  
Mitogen Activated Protein Kinase ◽  
Protective Effects ◽  
Induced Apoptosis

Ischemia-induced apoptosis of endothelial cells may contribute to tissue injury, organ failure, and transplantation rejection. However, little is known about survival mechanisms capable to counteract endothelial apoptosis. This study investigated the potential role of an endogenous anti-apoptotic response elicited by transient hypoxia, capable to avert ongoing apoptosis in endothelial cells. Experiments were carried out in three different types of cultured endothelial cells (human umbilical vein, pig aorta, and from rat coronary microvasculature). As a pro-apoptotic challenge endothelial cells were cultured in serum-free medium and subjected to hypoxia for 2 h. We found that transient hypoxia reduced caspase 3 activation within 1 h of hypoxia. Accordingly, the number of apoptotic cells was reduced after 24 h of reoxygenation. This was true for all three cell types analyzed. Analysis of Akt and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways revealed that hypoxia induced a transient activation of ERK 2 but not of Akt. ERK 2 phosphorylation preceded the phosphorylation of pro-apoptotic molecule Bad at Ser112, an inhibitory phosphorylation site specific for ERK. The protective effects of hypoxia regarding Bad phosphorylation, caspase 3 activation, and apoptosis were abolished by MEK 1/2 inhibitors, PD98059 or UO126, as well as by antisense oligonucleotides directed against ERK 1/2. Furthermore, inhibition of this pathway inhibited hypoxia-induced increase in mitochondrial membrane potential. The present study demonstrates that transient hypoxia induces a novel survival mechanism that protects endothelial cells against apoptosis. This endogenous process involves MEK/ERK-mediated inhibition of the pro-apoptotic molecule Bad and caspase 3.

scholarly journals Omega-3 fatty acids differentially alter the expression of detoxification enzymes and nitric oxide bioavailability in endothelial cells during IL-6 exposure

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S C R Sherratt ◽  
P Libby ◽  
D L Bhatt ◽  
H Dawoud ◽  
T Malinski ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Umbilical Vein ◽  
Calcium Ionophore ◽  
Detoxification Enzymes ◽  
Omega 3 ◽  
Private Company ◽  
Sod Isoforms ◽  
No Bioavailability

Abstract Background Atherosclerotic plaques can elaborate reactive oxygen species (ROS) that reduce nitric oxide (NO) bioavailability. Cellular detoxification enzymes including various peroxiredoxin (PRDX) and superoxide dismutase (SOD) isoforms can inactivate ROS. The omega-3 fatty acid (n3-FA) eicosapentaenoic acid (EPA) reduced cardiovascular (CV) events in high-risk patients (REDUCE-IT), a benefit not observed with mixed n3-FAs containing docosahexaenoic acid (DHA). Purpose The purpose of this study was to compare the effects of EPA and DHA on NO bioavailability and expression of detoxification enzymes in the vascular endothelium in vitro. Methods Human umbilical vein endothelial cells (HUVECs) were pretreated with EPA or DHA at equimolar levels (10 μM) for 2 h, then challenged with IL-6 at 12 ng/ml for 24 h. Proteomic analysis was performed using LC/MS to measure relative protein expression. Only significant (p<0.05) changes between treatment groups >1-fold were analyzed. Cells were stimulated with calcium ionophore to measure NO and peroxynitrite (ONOO-) release using a porphyrinic nanosensor. Results EPA, but not DHA, augmented PRDX-2 and SOD1 expression in HUVECs relative to IL-6 alone (1.2-fold and 1.6-fold, respectively, p=0.03). EPA also significantly lowered other isoforms unlike DHA. Either EPA or DHA increased thioredoxin expression by 1.5-fold (p=0.001) and 1.3-fold (p=0.02), respectively and decreased SOD2 expression by 1.5-fold (p=8.75E-11) and 1.6-fold (p=6.03E-9), respectively. IL-6 alone only increased expression of 6 detoxification enzymes by at least 1.2-fold, relative to vehicle. Unlike DHA, EPA also increased the NO to ONOO- release ratio by 36% (p<0.05) relative to IL-6 alone, without changes in NO synthase (eNOS) expression. Conclusions n3-FAs differentially influenced NO bioavailability and expression of ROS detoxification proteins, including peroxiredoxin and SOD isoforms. The net benefits of EPA on eNOS function and ROS detoxification may contribute to reduced atherothrombotic risk compared to DHA. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Amarin Pharma Inc., Elucida Research

scholarly journals Enhanced Autophagy in GAB1-Deficient Vascular Endothelial Cells Is Responsible for Atherosclerosis Progression

2021 ◽  
Vol 11 ◽  
Author(s):  
Xin Qian ◽  
Han Wang ◽  
Yuli Wang ◽  
Jiaquan Chen ◽  
Xiangjiang Guo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Adaptor Protein ◽  
Tube Formation ◽  
Mitogen Activated Protein Kinase ◽  
Atherosclerosis Progression ◽  
Sequestosome 1 ◽  
Atherosclerosis Treatment

Autophagy is a host machinery that controls cellular health. Dysfunction of autophagy is responsible for the pathogenesis of many human diseases that include atherosclerosis obliterans (ASO). Physiologically, host autophagy removes aging organelles and delays the formation of atherosclerotic plaque. However, in ischemia event, dysregulated autophagy can be induced to trigger autosis, leading to an inevitable cellular death. Grb2-associated binder 1 (GAB1) is a docking/scaffolding adaptor protein that regulates many cell processes including autophagy. Our study first reported that the protein expression of GAB1 significantly decreased in ASO. Mechanically, our results showed that inhibition of Akt (protein kinase B), the upstream of mTOR (mechanistic target of rapamycin), significantly enhanced autophagy by demonstrating the downregulation of p62/Sequestosome 1 expression and the upregulation of the ratio of LC3II/LC3I. Conversely, we found that the inhibition of ERK1/2 (extracellular signal-regulated kinases1/2), p38, and JNK (c-Jun N-terminal kinase) signaling pathway, respectively, significantly inhibited autophagy by demonstrating the upregulation of p62 expression and the downregulation of the ratio of LC3II/LC3I. Further, we demonstrated that knockdown of GAB1 significantly increased autophagy in HUVECs (human umbilical vein endothelial cells) via activation of MAPK (mitogen-activated protein kinase) pathways that include ERK1/2, p38, and JNK. Moreover, we found that knockdown of GAB1 profoundly inhibited HUVEC proliferation, migration, and tube formation. Taken together, this study first suggests that GAB1 is a key regulator of autophagy in HUVECs. Targeting GAB1 may serve as a potential strategy for the atherosclerosis treatment.

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