Downregulation of Dicer expression by serum withdrawal sensitizes human endothelial cells to apoptosis

2008 ◽  
Vol 295 (6) ◽  
pp. H2512-H2521 ◽  
Author(s):  
Satoshi Asada ◽  
Tomosaburo Takahashi ◽  
Koji Isodono ◽  
Atsuo Adachi ◽  
Hiroko Imoto ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Caspase 3 ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Serum Withdrawal ◽  
Tyrosine Kinase 2 ◽  
Nitric Oxide Synthase 3 ◽  
Induced Apoptosis ◽  
Dicer Expression ◽  
Umbilical Vein Endothelial Cells

Although the modulated expression of Dicer is documented upon neoplastic transformation, little is known of the regulation of Dicer expression by environmental stimuli and its roles in the regulation of cellular functions in primary cells. In this study, we found that Dicer expression was downregulated upon serum withdrawal in human umbilical vein endothelial cells (HUVECs). Serum withdrawal induced a time-dependent repression of Dicer expression, which was specifically rescued by vascular endothelial cell growth factor or sphingosine-1-phosphate. When Dicer expression was silenced by short-hairpin RNA against Dicer, the cells were more prone to apoptosis under serum withdrawal, whereas the rate of apoptosis was comparable with control cells in the serum-containing condition. Real-time PCR-based gene expression profiling identified several genes, the expression of which was modulated by Dicer silencing, including adhesion and matrix-related molecules, caspase-3, and nitric oxide synthase 3 (NOS3). Dicer silencing markedly impaired migratory functions without affecting cell adhesion and repressed phosphorylation of focal adhesion kinase and proline-rich tyrosine kinase 2 in adherent HUVECs. Dicer knockdown upregulated caspase-3 and downregulated NOS3 expression, and serum withdrawal indeed increased caspase-3 and decreased NOS3 expression. Furthermore, the overexpression of Dicer in HUVECs resulted in a marked reduction in apoptosis upon serum withdrawal and a decreased caspase-3 and increased NOS3 expression. The inhibition of NOS activity by Nω-nitro-l-arginine methyl ester abrogated the effect of Dicer overexpression to rescue the cells from serum withdrawal-induced apoptosis. These results indicated that serum withdrawal decreases Dicer expression, leading to an increased susceptibility to apoptosis through the regulation of caspase-3 and NOS3 expression.

scholarly journals Regulation of Apoptosis by Vitamin C

2001 ◽  
Vol 276 (50) ◽  
pp. 46835-46840 ◽  
Author(s):  
Margret C. M. Vissers ◽  
Wai-Gin Lee ◽  
Mark B. Hampton
Keyword(s):  
Endothelial Cells ◽  
Vitamin C ◽  
Caspase 3 ◽  
Hypochlorous Acid ◽  
Umbilical Vein ◽  
Extended Period ◽  
Iodide Uptake ◽  
Serum Withdrawal ◽  
Initiation Phase ◽  
Umbilical Vein Endothelial Cells

We have investigated the ability of intracellular vitamin C to protect human umbilical vein endothelial cells from exposure to hypochlorous acid (HOCl) and a range of derived chloramines. Ascorbate provided minimal protection against the cytotoxicity induced by these oxidants, as measured by propidium iodide uptake. In contrast, there was a marked effect on apoptosis, monitored by caspase-3 activation and phosphatidylserine exposure. Extended incubation of the cells with glycine chloramine or histamine chloramine completely blocked apoptosis initiated in the cells by serum withdrawal. This effect was significantly abrogated by ascorbate. Inhibition of apoptosis required the oxidant to be present for an extended period after serum withdrawal and occurred prior to caspase-3 activation. General protection of thiols by ascorbate was not responsible for the protection of apoptosis, because intracellular oxidation by HOCl or chloramines was not prevented in supplemented cells. The results suggest a new role for vitamin C in the regulation of apoptosis. We propose that, by protection of an oxidant-sensitive step in the initiation phase, ascorbate allows apoptosis to proceed in endothelial cells under sustained oxidative stress.

scholarly journals The antioxidant effects of quercetin metabolites on the prevention of high glucose-induced apoptosis of human umbilical vein endothelial cells

2008 ◽  
Vol 101 (8) ◽  
pp. 1165-1170 ◽  
Author(s):  
Chia-Lun Chao ◽  
Yu-Chi Hou ◽  
Pei-Dawn Lee Chao ◽  
Ching-Sung Weng ◽  
Feng-Ming Ho
Keyword(s):  
Endothelial Cells ◽  
Ascorbic Acid ◽  
High Glucose ◽  
Caspase 3 ◽  
Umbilical Vein ◽  
Dependent Manner ◽  
Human Umbilical Vein ◽  
Micromolar Concentration ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Diabetes mellitus is an important risk factor for CVD. A previous study showed that high glucose induced the apoptosis of human umbilical vein endothelial cells (HUVEC) via the sequential activation of reactive oxygen species, Jun N-terminal kinase (JNK) and caspase-3. The apoptosis cascade could be blocked by ascorbic acid at the micromolar concentration (100 μm). In addition to ascorbic acid, quercetin, the most abundant dietary flavonol, has been recently actively studied in vascular protection effects due to its antioxidant effect at low micromolar concentrations (10–50 μm). Quercetin sulfate/glucuronide, the metabolite of quercetin in blood, however, has been rarely evaluated. In the present study, we investigated the effect of quercetin sulfate/glucuronide on the prevention of high glucose-induced apoptosis of HUVEC. HUVEC were treated with media containing high glucose (33 mm) in the presence or absence of ascorbic acid (100 μm) or quercetin sulfate/glucuronide (100 nm, 300 nm and 1 μm). For the detection of apoptosis, a cell death detection ELISA assay was used. The level of intracellular H2O2 was measured by flow cytometry. JNK and caspase-3 were evaluated by a kinase activity assay and Western blot analysis. The results showed that high glucose-induced apoptosis was inhibited by quercetin sulfate/glucuronide in a dose-dependent manner. The effect of quercetin sulfate/glucuronide on H2O2 quenching, inhibition of JNK and caspase-3 activity at the nanomolar concentration (300 nm) was similar to that of ascorbic acid at the micromolar concentration (100 μm). The findings of the present study may shed light on the pharmacological application of quercetin in CVD.

scholarly journals Isosamidin from Peucedanum japonicum Roots Prevents Methylglyoxal-Induced Glucotoxicity in Human Umbilical Vein Endothelial Cells via Suppression of ROS-Mediated Bax/Bcl-2

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 531
Author(s):  
Moon Ho Do ◽  
Jae Hyuk Lee ◽  
Jongmin Ahn ◽  
Min Jee Hong ◽  
Jinwoong Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Endothelial Dysfunction ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Vascular Complications ◽  
In Vivo Models ◽  
Human Umbilical Vein ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Methylglyoxal (MGO) is a highly reactive metabolite of glucose. Elevated levels of MGO induce the generation of reactive oxygen species (ROS) and cause cell death in endothelial cells. Vascular endothelial cell damage by ROS has been implicated in the progression of diabetic vascular complications, cardiovascular diseases, and atherosclerosis. In this study, the protective effect of isosamidin, isolated from Peucedanum japonicum roots, on MGO-induced apoptosis was investigated using human umbilical vein endothelial cells (HUVECs). Among the 20 compounds isolated from P. japonicum, isosamidin showed the highest effectiveness in inhibiting MGO-induced apoptosis of HUVECs. Pretreatment of HUVECs with isosamidin significantly prevented the generation of ROS and cell death induced by MGO. Isosamidin prevented MGO-induced apoptosis in HUVECs by downregulating the expression of Bax and upregulating the expression of Bcl-2. MGO treatment activated mitogen-activated protein kinases (MAPKs), such as p38, c-Jun N terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). In contrast, pretreatment with isosamidin strongly inhibited the activation of p38 and JNK. Furthermore, isosamidin caused the breakdown of the crosslinks of the MGO-derived advanced glycation end products (AGEs). These findings suggest that isosamidin from P. japonicum may be used as a preventive agent against MGO-mediated endothelial dysfunction in diabetes. However, further study of the therapeutic potential of isosamidin on endothelial dysfunction needs to explored in vivo models.

scholarly journals α-Mangostin protects against high-glucose induced apoptosis of human umbilical vein endothelial cells

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Yanli Luo ◽  
Minxiang Lei
Keyword(s):  
High Glucose ◽  
Caspase 3 ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Vascular Complications ◽  
Vascular Endothelial ◽  
Apoptosis Rate ◽  
Diabetic Vascular Complications ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Diabetic vascular complications result from high-glucose induced vascular endothelial cell dysfunction. There is an emerging need for novel drugs with vascular endothelial cell protective effects for the treatment of diabetic vascular complications. The present study aimed to investigate the protective effect of α-mangostin against high-glucose induced apoptosis of cultured human umbilical vein endothelial cells (HUVECs). HUVECs were treated with glucose to induce apoptosis. The expression of the apoptosis-related proteins, Bcl-2, Bax, and cleaved caspase-3, were detected by Western blotting. Ceramide concentration and acid sphingomyelinase (ASM) activity were assayed by HPLC. The cell apoptosis rate was detected by flow cytometry after staining with annexin V/propidium iodide (PI). Compared with HUVECs cultured in 5 mM glucose, cells cultured in 30 mM glucose exhibited a higher apoptosis rate, up-regulation of cleaved caspase-3 and Bax (proapoptotic proteins), down-regulation of Bcl-2 (anti-apoptotic protein), increased ceramide concentration, and enhanced ASM activity (all P<0.05). α-Mangostin (15 µM) significantly attenuated the high-glucose induced increase in apoptosis rate (8.64 ± 2.16 compared with 19.6 ± 3.54%), up-regulation of cleaved caspase-3 and Bax, down-regulation of Bcl-2, elevation of ceramide level, and enhancement of ASM activity (all P<0.05). The effects of desipramine were similar to those of α-mangostin. The protective effect of α-mangostin on high-glucose induced apoptotic damage may be mediated by an inhibition of ASM and thus a decreased level of ceramide.

SAR131675 Receptor Tyrosine Kinase Inhibitor Induces Apoptosis through Bcl-2/Bax/Cyto c Mitochondrial Pathway in Human Umbilical Vein Endothelial Cells

2021 ◽  
Vol 21 ◽  
Author(s):  
Zeinab Babaei ◽  
Mojtaba Panjehpour ◽  
Hadi Parsian ◽  
Mahmoud Aghaei
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Umbilical Vein ◽  
Ros Generation ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Background: Tyrosine kinase inhibitors (TKIs) can be used to inhibit cancer cell proliferation by targeting the vascular endothelial growth factor receptor (VEGFR) family. SAR131675 is a highly selective receptor tyrosine kinase inhibitor to VEGFR3 that reveals the inhibitory effect on proliferation in human lymphatic endothelial cells. However, the molecular mechanisms underlying this process are generally unclear. Objective: This study was performed to investigate the possible involvement of the Bcl-2/Bax/Cyto c apoptosis pathway in human umbilical vein endothelial cells (HUVECs). In addition, the role of reactive oxygen species (ROS) and mitochondrial membrane potential was evaluated. Methods: The effect of SAR131675 on HUVEC cell viability was evaluated by MTT assay. The activity of SAR131675 in inducing apoptosis was carried out through the detection of Annexin V-FITC/PI signal by flow cytometry. To determine the mechanisms underlying SAR131675 induced apoptosis, the mitochondrial membrane potential, ROS generation, the activity of caspase-3, and expression of apoptosis-related proteins such as Bcl-2, Bax, and cytochrome c were evaluated in HUVECs. Results: SAR131675 significantly inhibited cell viability and induced apoptosis in HUVECs in a dose-dependent manner. Moreover, SAR131675 induced mitochondrial dysfunction, ROS generation, Bcl-2 down-regulation, Bax up-regulation, cytochrome c release, and caspase-3 activation, which displays features of the mitochondria-dependent apoptosis signaling pathway. Conclusion: Our present data demonstrated that SAR131675-induced cytotoxicity in HUVECs is associated with the mitochondria apoptotic pathway. These results suggest that further studies are required to fully elucidate the role of TKIs in these cellular processes.

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