scholarly journals Exendin-4 protects endothelial cells from lipoapoptosis by PKA, PI3K, eNOS, p38 MAPK, and JNK pathways

2013 ◽  
Vol 50 (2) ◽  
pp. 229-241 ◽  
Author(s):  
Özlem Erdogdu ◽  
Linnéa Eriksson ◽  
Hua Xu ◽  
Åke Sjöholm ◽  
Qimin Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
P38 Mapk ◽  
Experimental Studies ◽  
Receptor Activation ◽  
No Production ◽  
Ros Production ◽  
Human Coronary Artery ◽  
Glucagon Like Peptide 1 ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Experimental studies have indicated that endothelial cells play an important role in maintaining vascular homeostasis. We previously reported that human coronary artery endothelial cells (HCAECs) express the glucagon-like peptide 1 (GLP1) receptor and that the stable GLP1 mimetic exendin-4 is able to activate the receptor, leading to increased cell proliferation. Here, we have studied the effect of exendin-4 and native GLP1 (7–36) on lipoapoptosis and its underlying mechanisms in HCAECs. Apoptosis was assessed by DNA fragmentation and caspase-3 activation, after incubating cells with palmitate. Nitric oxide (NO) and reactive oxidative species (ROS) were analyzed. GLP1 receptor activation, PKA-, PI3K/Akt-, eNOS-, p38 MAPK-, and JNK-dependent pathways, and genetic silencing of transfection of eNOS were also studied. Palmitate-induced apoptosis stimulated cells to release NO and ROS, concomitant with upregulation of eNOS, which required activation of p38 MAPK and JNK. Exendin-4 restored the imbalance between NO and ROS production in which ROS production decreased and NO production was further augmented. Incubation with exendin-4 and GLP1 (7–36) protected HCAECs against lipoapoptosis, an effect that was blocked by PKA, PI3K/Akt, eNOS, p38 MAPK, and JNK inhibitors. Genetic silencing of eNOS also abolished the anti-apoptotic effect afforded by exendin-4. Our results support the notion that GLP1 receptor agonists restore eNOS-induced ROS production due to lipotoxicity and that such agonists protect against lipoapoptosis through PKA-PI3K/Akt-eNOS-p38 MAPK-JNK-dependent pathways via a GLP1 receptor-dependent mechanism.

scholarly journals Ang (1–7) Protects Islet Endothelial Cells from Palmitate-Induced Apoptosis by AKT, eNOS, p38 MAPK, and JNK Pathways

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Li Yuan ◽  
Chun-Li Lu ◽  
Ying Wang ◽  
Yang Li ◽  
Xiao-Ya Li
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
P38 Mapk ◽  
Reactive Oxygen ◽  
Treated Group ◽  
Ros Production ◽  
Oxygen Species ◽  
Concomitant Reduction ◽  
Jnk Inhibitors ◽  
Induced Apoptosis

This study aimed to explore the effect of angiotensin (1–7) (Ang (1–7)) on palmitate-induced apoptosis in islet endothelial cells and the mechanism of action. MS-1 cells were treated with palmitate in the presence or absence of Ang (1–7). The percentage of apoptotic cells was determined by DNA fragmentation and flow cytometry. Reactive oxygen species (ROS) production was measured using a Reactive Oxygen Species Assay Kit. Expression of AKT, eNOS, C-Jun N-terminal kinase (JNK), and p38 was detected by western blotting. Compared with palmitate treated group, palmitate-induced apoptosis was decreased in MS-1 cells which were preincubated with Ang (1–7) (P<0.05). Palmitate decreased the phosphorylation of AKT and eNOS, and Ang (1–7) increased the phosphorylation of these kinases (P<0.05), with a concomitant reduction in MS-1 cells apoptosis. Ang (1–7) also inhibited the palmitate-induced ROS production and attenuated the apoptosis-related signaling molecule JNK and p38 activation (allP<0.05). PI3K/AKT, eNOS, p38 MAPK, and JNK inhibitors blocked the antilipoapoptosis of Ang (1–7) (allP<0.05). Our findings suggest that Ang (1–7) reduces palmitate-induced islet endothelial cells apoptosis. AKT/eNOS/NO signaling and JNK and p38 pathway are involved in the Ang (1–7)-mediated modulation of islet endothelial cells lipoapoptosis.

scholarly journals p38 Mitogen-Activated Protein Kinase Mediates Palmitate-Induced Apoptosis But Not Inhibitor of Nuclear Factor-κB Degradation in Human Coronary Artery Endothelial Cells

Endocrinology ◽  
2007 ◽  
Vol 148 (4) ◽  
pp. 1622-1628 ◽  
Author(s):  
Weidong Chai ◽  
Zhenqi Liu
Keyword(s):  
Fatty Acids ◽  
Endothelial Cells ◽  
Coronary Artery ◽  
P38 Mapk ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Human Coronary Artery ◽  
Mapk Activity ◽  
Induced Apoptosis

Plasma free fatty acids are elevated in patients with type 2 diabetes and contribute to the pathogenesis of insulin resistance and endothelial dysfunction. The p38 MAPK mediates stress, inflammation, and apoptosis. Whether free fatty acids induce apoptosis and/or activate nuclear factor-κB inflammatory pathway in human coronary artery endothelial cells (hCAECs) and, if so, whether this involves the p38 MAPK pathway is unknown. hCAECs (passages 4–6) were grown to 70% confluence and then incubated with palmitate at concentrations of 0–300 μm for 6–48 h. Palmitate at 100, 200, or 300 μm markedly increased apoptosis after 12 h of incubation. This apoptotic effect was time (P = 0.008) and dose (P = 0.006) dependent. Palmitate (100 μm for 24 h) induced a greater than 2-fold increase in apoptosis, which was accompanied with a 4-fold increase in p38 MAPK activity (P &lt; 0.001). Palmitate did not affect the phosphorylation of Akt1 or ERK1/2. SB203580 (a specific inhibitor of p38 MAPK) alone did not affect cellular apoptosis; however, it abolished palmitate-induced apoptosis and p38 MAPK activation. Palmitate significantly reduced the level of inhibitor of nuclear factor-κB (IκB). However, treatment of cells with SB203580 did not restore IκB to baseline. We conclude that palmitate induces hCAEC apoptosis via a p38 MAPK-dependent mechanism and may participate in coronary endothelial injury in diabetes. However, palmitate-mediated IκB degradation in hCAECs is independent of p38 MAPK activity.

Ox-LDL induces apoptosis in human coronary artery endothelial cells: role of PKC, PTK, bcl-2, and Fas

1998 ◽  
Vol 275 (2) ◽  
pp. H568-H576 ◽  
Author(s):  
Dayuan Li ◽  
Baichun Yang ◽  
Jawahar L. Mehta
Keyword(s):  
Endothelial Cells ◽  
Protein Tyrosine Kinase ◽  
Low Density Lipoprotein ◽  
Critical Role ◽  
Light And Electron Microscopy ◽  
Density Lipoprotein ◽  
Human Coronary Artery ◽  
Underlying Mechanisms ◽  
Induced Apoptosis ◽  
Hypoxia Reoxygenation

Oxidized low-density lipoprotein (ox-LDL) plays a critical role in the development of atherosclerosis. Recent studies show that ox-LDL may induce apoptosis of cultured rabbit smooth muscle cells and human macrophages. This study was designed to determine the modulation by ox-LDL of apoptosis in cultured human coronary arterial endothelial cells (HCAEC) during hypoxia-reoxygenation and to determine underlying mechanisms. When HCAEC were ∼85% confluent, the cells were exposed to hypoxia (24 h)-reoxygenation (3 h), native LDL, or ox-LDL. Fragmented DNA end-labeling, DNA laddering, and light and electron microscopy were used to determine changes characteristic of apoptosis. Ox-LDL (20 μg/ml) increased apoptosis during hypoxia-reoxygenation compared with hypoxia-reoxygenation alone ( P < 0.05). Low concentrations of ox-LDL (5 μg/ml) and native LDL (20 μg/ml) under identical conditions had no effect on the degree of apoptosis. Ox-LDL markedly decreased endogenous superoxide dismutase activity and increased lipid peroxidation in HCAEC. The presence of ox-LDL, but not native LDL, in cultured HCAEC resulted in the activation of protein kinase C (PKC) and protein tyrosine kinase (PTK). The specific PKC and PTK inhibitors significantly reduced ox-LDL-mediated apoptosis of HCAEC ( P < 0.05). Hypoxia-reoxygenation significantly increased Fas expression and decreased bcl-2 expression in HCAEC lysate as determined by Western analysis. Ox-LDL further increased Fas expression and decreased bcl-2 expression. These data indicate that ox-LDL enhances hypoxia-reoxygenation-mediated apoptosis in HCAEC. Ox-LDL-mediated apoptosis of HCAEC appears to involve activation of PKC and PTK. In addition, ox-LDL modulates Fas and bcl-2 protein expression in HCAEC. This study also suggests that ox-LDL is more important than native LDL in hypoxia-reoxygenation-induced apoptosis.

scholarly journals Sodium Glucose Co-Transporter 2 Inhibitors Ameliorate Endothelium Barrier Dysfunction Induced by Cyclic Stretch through Inhibition of Reactive Oxygen Species

2021 ◽  
Vol 22 (11) ◽  
pp. 6044
Author(s):  
Xiaoling Li ◽  
Gregor Römer ◽  
Raphaela P. Kerindongo ◽  
Jeroen Hermanides ◽  
Martin Albrecht ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Reactive Oxygen ◽  
Cyclic Stretch ◽  
Cell Permeability ◽  
Ros Production ◽  
Oxygen Species ◽  
Barrier Dysfunction ◽  
Human Coronary Artery ◽  
Oxidative Effect

SGLT-2i’s exert direct anti-inflammatory and anti-oxidative effects on resting endothelial cells. However, endothelial cells are constantly exposed to mechanical forces such as cyclic stretch. Enhanced stretch increases the production of reactive oxygen species (ROS) and thereby impairs endothelial barrier function. We hypothesized that the SGLT-2i’s empagliflozin (EMPA), dapagliflozin (DAPA) and canagliflozin (CANA) exert an anti-oxidative effect and alleviate cyclic stretch-induced endothelial permeability in human coronary artery endothelial cells (HCAECs). HCAECs were pre-incubated with one of the SGLT-2i’s (1 µM EMPA, 1 µM DAPA and 3 µM CANA) for 2 h, followed by 10% stretch for 24 h. HCAECs exposed to 5% stretch were considered as control. Involvement of ROS was measured using N-acetyl-l-cysteine (NAC). The sodium-hydrogen exchanger 1 (NHE1) and NADPH oxidases (NOXs) were inhibited by cariporide, or GKT136901, respectively. Cell permeability and ROS were investigated by fluorescence intensity imaging. Cell permeability and ROS production were increased by 10% stretch; EMPA, DAPA and CANA decreased this effect significantly. Cariporide and GKT136901 inhibited stretch-induced ROS production but neither of them further reduced ROS production when combined with EMPA. SGLT-2i’s improve the barrier dysfunction of HCAECs under enhanced stretch and this effect might be mediated through scavenging of ROS. Anti-oxidative effect of SGLT-2i’s might be partially mediated by inhibition of NHE1 and NOXs.

scholarly journals (−)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells

2011 ◽  
Vol 300 (4) ◽  
pp. C880-C887 ◽  
Author(s):  
Israel Ramirez-Sanchez ◽  
Lisandro Maya ◽  
Guillermo Ceballos ◽  
Francisco Villarreal
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Cardiovascular Effects ◽  
Mesenteric Arteries ◽  
No Production ◽  
Human Coronary Artery ◽  
Calmodulin Binding ◽  
Pathway Activation ◽  
Functional Relevance ◽  
Endothelial Nitric Oxide

The consumption of cacao-derived (i.e., cocoa) products provides beneficial cardiovascular effects in healthy subjects as well as individuals with endothelial dysfunction such as smokers, diabetics, and postmenopausal women. The vascular actions of cocoa are related to enhanced nitric oxide (NO) production. These actions can be reproduced by the administration of the cacao flavanol (−)-epicatechin (EPI). To further understand the mechanisms behind the vascular action of EPI, we investigated the effects of Ca2+ depletion on endothelial nitric oxide (NO) synthase (eNOS) activation/phosphorylation and translocation. Human coronary artery endothelial cells were treated with EPI or with bradykinin (BK), a well-known Ca2+-dependent eNOS activator. Results demonstrate that both EPI and BK induce increases in intracellular calcium and NO levels. However, under Ca2+-free conditions, EPI (but not BK) is still capable of inducing NO production through eNOS phosphorylation at serine 615, 633, and 1177. Interestingly, EPI-induced translocation of eNOS from the plasmalemma was abolished upon Ca2+ depletion. Thus, under Ca2+-free conditions, EPI can stimulate NO synthesis independent of calmodulin binding to eNOS and of its translocation into the cytoplasm. We also examined the effect of EPI on the NO/cGMP/vasodilator-stimulated phosphoprotein (VASP) pathway activation in isolated Ca2+-deprived canine mesenteric arteries. Results demonstrate that under these conditions, EPI induces the activation of this vasorelaxation-related pathway and that this effect is inhibited by pretreatment with nitro-l-arginine methyl ester, suggesting a functional relevance for this phenomenon.

FERM domain promotes resveratrol-induced apoptosis in endothelial cells via inhibition of NO production

2013 ◽  
Vol 441 (4) ◽  
pp. 891-896 ◽  
Author(s):  
Hye-Rim Lee ◽  
Jongmin Kim ◽  
Jinsun Park ◽  
Sunyoung Ahn ◽  
Eunsil Jeong ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
No Production ◽  
Ferm Domain ◽  
Induced Apoptosis

scholarly journals Metformin Alleviated Aβ-Induced Apoptosis via the Suppression of JNK MAPK Signaling Pathway in Cultured Hippocampal Neurons

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bin Chen ◽  
Ying Teng ◽  
Xingguang Zhang ◽  
Xiaofeng Lv ◽  
Yanling Yin
Keyword(s):  
P38 Mapk ◽  
Hippocampal Neurons ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ldh Assay ◽  
Underlying Mechanisms ◽  
Induced Apoptosis ◽  
Positive Effect

Both diabetes and hyperinsulinemia are confirmed risk factors for Alzheimer’s disease. Some researchers proposed that antidiabetic drugs may be used as disease-modifying therapies, such as metformin and thiazolidinediones, although more evidence was poorly supported. The aim of the current study is to investigate the role of metformin in Aβ-induced cytotoxicity and explore the underlying mechanisms. First, the experimental results show that metformin salvaged the neurons exposed to Aβin a concentration-dependent manner with MTT and LDH assay. Further, the phosphorylation levels of JNK, ERK1/2, and p38 MAPK were measured with western blot analysis. It was investigated that Aβincreased phospho-JNK significantly but had no effect on phospho-p38 MAPK and phospho-ERK1/2. Metformin decreased hyperphosphorylated JNK induced by Aβ; however, the protection of metformin against Aβwas blocked when anisomycin, the activator of JNK, was added to the medium, indicating that metformin performed its protection against Aβin a JNK-dependent way. In addition, it was observed that metformin protected the neurons via the suppression of apoptosis. Taken together, our findings demonstrate that metformin may have a positive effect on Aβ-induced cytotoxicity, which provides a preclinical strategy against AD for elders with diabetes.

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