scholarly journals Bubbles Induce Endothelial Microparticle Formation via a Calcium-Dependent Pathway Involving Flippase Inactivation and Rho Kinase Activation

2018 ◽  
Vol 46 (3) ◽  
pp. 965-974 ◽  
Author(s):  
Xuhua Yu ◽  
Jiajun Xu ◽  
Wenwu Liu ◽  
Weigang Xu

Background/Aims: Intravascular bubbles can exert pleiotropic detrimental effects, partly by inducing endothelial microparticles (EMPs) production, which play critical roles in cell communication and vascular inflammation cascades. However, the underlying mechanisms remain unclear. This study aimed to delineate the possible mechanisms involving bubble-induced EMPs formation. Methods: Human umbilical vein endothelial cells (HUVECs) were contacted by bubbles and EMPs level in supernatant were quantified by flow cytometry. Cytoplasmic calcium (Ca2+) was measured by the Ca2+ binding dyes Fluo-3 AM and flippase activity was assessed by translocation rate of fluorescent phosphatidylserine (PS) analogue NBD-PS. Protein levels of phospho-myosin light chain (MLC, a Rho kinase substrate) and phospho-extracellular signal-regulated kinase 1 or 2 (ERK1/2) were determined by western blotting. The score of actin colocalization was assessed by phalloidin-FITC using an immunofluorescent microscopy. Results: EMPs level markedly increased after bubble stimulus. Cytoplasmic calcium (Ca2+) significantly elevated (P< 0.05), flippase activity decreased (P< 0.05), protein levels of phospho- MLC and phospho- ERK1/2 significantly increased (P< 0.05, P < 0.05), and the score of actin colocalization markedly reduced (P< 0.05) in bubble-stimulated HUVECs. All the above changes except the increase in phospho-ERK1/2 can be reversed by Ca2+ channel blocker LaCl3 (P< 0.05). Additionally, MLC phosphorylation was significantly inhibited and actin colocalization markedly increased by Rho kinase inhibitor pretreatment and more importantly, bubble-induced EMPs markedly decreased. Conclusions: These results demonstrate that bubble stimulates EMPs formation by cytoplasmic Ca2+ elevation and subsequently activating Rho kinase pathway and cytoskeleton reorganization. Simultaneously, cytoplasmic Ca2+ inhibits the flippase activity and subsequently increases phosphatidylserine exposure, which also contributes to EMPs formation.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Zhang ◽  
Chun-Mei Wang ◽  
Jing Li ◽  
Zhao-Jie Meng ◽  
Sheng-Nan Wei ◽  
...  

Endothelial dysfunction is a critical factor during the initiation of cardiovascular complications in diabetes. Berberine can ameliorate endothelial dysfunction induced by diabetes. However, the underlying mechanisms remain unclear. The aim of this study was to investigate the protective effect and mechanism of berberine on palmitate-induced endothelial dysfunction in human umbilical vein endothelial cells (HUVECs). The cell viability of HUVECs was determined by MTT assays. Nitric oxide (NO) level and production of reactive oxygen species (ROS) were determined in supernatants or in the cultured HUVECs. The mRNA level of endothelial nitric oxide synthase (eNOS) was measured by RT-PCR, and the protein levels of eNOS, p-eNOS, Akt, p-Akt, AMPK, p-AMPK, and NADPH oxidase (NOX4) were analyzed. The results demonstrated that berberine significantly elevated NO levels and reduced the production of ROS. The expressions of eNOS were significantly increased, while NOX4 protein expression was decreased in berberine-treated HUVECs. Moreover, berberine upregulated the protein expression of AMPK and p-AMPK in palmitate-treated HUVECs, but had no effect on the levels of Akt. Therefore, berberine ameliorates palmitate-induced endothelial dysfunction by upregulating eNOS expression and downregulating expression of NOX4. This regulatory effect of berberine may be related to the activation of AMPK.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Zhimin Zhang ◽  
Congying Wei ◽  
Yanfen Zhou ◽  
Tao Yan ◽  
Zhengqiang Wang ◽  
...  

Homocysteine- (Hcy-) induced endothelial cell apoptosis has been suggested as a cause of Hcy-dependent vascular injury, while the proposed molecular pathways underlying this process are unclear. In this study, we investigated the adverse effects of Hcy on human umbilical vein endothelial cells (HUVEC) and the underlying mechanisms. Our results demonstrated that moderate-dose Hcy treatment induced HUVEC apoptosis in a time-dependent manner. Furthermore, prolonged Hcy treatment increased the expression of NOX4 and the production of intracellular ROS but decreased the ratio of Bcl-2/Bax and mitochondrial membrane potential (MMP), resulting in the leakage of cytochrome c and activation of caspase-3. Prolonged Hcy treatment also upregulated glucose-regulated protein 78 (GRP78), activated protein kinase RNA-like ER kinase (PERK), and induced the expression of C/EBP homologous protein (CHOP) and the phosphorylation of NF-κb. The inhibition of NOX4 decreased the production of ROS and alleviated the Hcy-induced HUVEC apoptosis and ER stress. Blocking the PERK pathway partly alleviated Hcy-induced HUVEC apoptosis and the activation of NF-κb. Taken together, our results suggest that Hcy-induced mitochondrial dysfunction crucially modulated apoptosis and contributed to the activation of ER stress in HUVEC. The excessive activation of the PERK pathway partly contributed to Hcy-induced HUVEC apoptosis and the phosphorylation of NF-κb.


Author(s):  
Suleyman Ilhan ◽  
Gamze Dilekci ◽  
Adem Guner ◽  
Hakan Bektas

Background: Investigating the effects of newly synthesized agents on various molecular mechanisms to understand their mechanism of action is an important step of pre-clinical screening. Benzimidazoles are composed of a unique fused benzene and imidazole ring and have attracted great attention due to their broad bioactivities, including antitumor. Objective: In the current study, we reported the synthesis of novel benzimidazole derivatives and investigated the possible cytotoxic and anti-angiogenic effects on human prostate cancer and umbilical vein endothelial cells (HUVECs). Methods: MTT assay was used to assess cell viability. A scratch assay was conducted to monitor the migration of cells. mRNA expression levels of VEGF, MMP-2, and MMP-9 were evaluated using qPCR. Changes in protein levels were evaluated by western blotting. Results: Compound G1, having a chlorine moiety, showed a potent cytotoxic activity on both prostate cancer cells and HUVECs, and inhibited cell migration via decreasing the mRNA and protein levels of key angiogenesis-related molecules such as VEGF, MMP-2, and MMP-9. Conclusion: These results suggest that newly synthesized G1 may be a novel anti-angiogenic agent for prostate cancer treatment.


2019 ◽  
Vol 20 (21) ◽  
pp. 5383 ◽  
Author(s):  
Li Zhang ◽  
Feifei Wang ◽  
Qing Zhang ◽  
Qiuming Liang ◽  
Shumei Wang ◽  
...  

Inflammation is a key mediator in the progression of atherosclerosis (AS). Benzoinum, a resin secreted from the bark of Styrax tonkinensis, has been widely used as a form of traditional Chinese medicine in clinical settings to enhance cardiovascular function, but the active components of the resin responsible for those pharmaceutical effects remain unclear. To better clarify these components, a new phenylpropane derivative termed stybenpropol A was isolated from benzoinum and characterized via comprehensive spectra a nalysis. We further assessed how this phenylpropane derivative affected treatment of human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor-α (TNF-α). Our results revealed that stybenpropol A reduced soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-8 (IL-8), and interleukin-1β (IL-1β) expression by ELISA, inhibited apoptosis, and accelerated nitric oxide (NO) release in TNF-α-treated HUVECs. We further found that stybenpropol A decreased VCAM-1, ICAM-1, Bax, and caspase-9 protein levels, and increased the protein levels of Bcl-2, IKK-β, and IκB-α. This study identified a new, natural phenylpropane derivative of benzoinum, and is the first to reveal its cytoprotective effects in the context of TNF-α-treated HUVECs via regulation of the NF-κB and caspase-9 signaling pathways.


1995 ◽  
Vol 108 (3) ◽  
pp. 1165-1174
Author(s):  
K. Jewell ◽  
C. Kapron-Bras ◽  
P. Jeevaratnam ◽  
S. Dedhar

The interaction of cells with components of the extracellular matrix through their integrin receptors results in the stimulation of tyrosine phosphorylation of several proteins, suggesting that these receptors play a key role in signal transduction. Here we report that antibody-mediated ligation and clustering of alpha 3 beta 1 and alpha 6 beta 1/alpha 6 beta 4 integrins resulted in the stimulation of tyrosine phosphorylation of proteins that are specific for each heterodimer. Thus, ligation and clustering of the alpha 3 beta 1 integrin on human prostate carcinoma cells (PC-3) and human umbilical vein endothelial cells (HUVEC) with anti-alpha 3 antibodies resulted in the stimulation of tyrosine phosphorylation of a 55 kDa protein. In contrast, ligation and clustering of the alpha 6 beta 1 integrin on these cells with anti-alpha 6 antibody resulted in the dramatic stimulation of tyrosine phosphorylation of a 90 kDa protein in addition to a 52 kDa protein, and ligation and clustering of alpha 5 beta 1 on HUVEC did not result in the apparent stimulation of tyrosine phosphorylation of any proteins. Clustering with anti-beta 1 antibodies triggered the tyrosine phosphorylation of all of these proteins, whereas ligation and clustering of PC-3 cells with an anti-beta 4 antibody resulted in the tyrosine phosphorylation of a distinct 62 kDa protein. Since the PC-3 cells express both alpha 6 beta 1 and alpha 6 beta 4, these data suggest that these two receptors can transduce distinct signals. All of the phosphorylations could be inhibited by treating the cells with Genistein, a tyrosine kinase inhibitor. Antibody-mediated ligation and clustering of integrins on the two types of cells did not result in the stimulation of tyrosine phosphorylation of pp125 focal adhesion kinase, although this was observed upon cell attachment and spreading on fibronectin, laminin and anti-alpha 3 monoclonal antibody. Collectively, these data demonstrate that cross-linking of different integrin heterodimers can stimulate tyrosine kinase activities, leading to the phosphorylation of distinct proteins, which are also different from those observed when cells are allowed to spread on a matrix.


Sign in / Sign up

Export Citation Format

Share Document