scholarly journals Impaired Autophagy Induced by oxLDL/β2GPI/anti-β2GPI Complex through PI3K/AKT/mTOR and eNOS Signaling Pathways Contributes to Endothelial Cell Dysfunction

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Guiting Zhang ◽  
Chao He ◽  
Qianqian Wu ◽  
Guoying Xu ◽  
Ming Kuang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Signaling Pathways ◽  
Western Blotting ◽  
Endothelial Injury ◽  
Vascular Endothelial ◽  
Endothelial Cell Dysfunction ◽  
Western Blotting Analysis ◽  
Cell Dysfunction ◽  
Glycoprotein I

Endothelial cell dysfunction plays a fundamental role in the pathogenesis of atherosclerosis (AS), and endothelial autophagy has protective effects on the development of AS. Our previous study had shown that oxidized low-density lipoprotein/β2-glycoprotein I/anti-β2-glycoprotein I antibody (oxLDL/β2GPI/anti-β2GPI) complex could promote the expressions of inflammatory cytokines and enhance the adhesion of leukocytes to endothelial cells. In the present study, we aimed to assess the effects of oxLDL/β2GPI/anti-β2GPI complex on endothelial autophagy and explore the associated potential mechanisms. Human umbilical vein endothelial cells (HUVECs) and mouse brain endothelial cell line (bEnd.3) were used as models of the vascular endothelial cells. Autophagy was evaluated by examining the expressions of autophagic proteins using western blotting analysis, autophagosome accumulation using transmission electron microscopy, and RFP-GFP-LC3 adenoviral transfection and autophagic flux using lysosome inhibitor chloroquine. The expressions of phospho-PI3K, phospho-AKT, phospho-mTOR, and phospho-eNOS were determined by western blotting analysis. 3-Methyladenine (3-MA) and rapamycin were used to determine the role of autophagy in oxLDL/β2GPI/anti-β2GPI complex-induced endothelial cell dysfunction. We showed that oxLDL/β2GPI/anti-β2GPI complex suppressed the autophagy, evidenced by an increase in p62 protein, a decrease in LC3-II and Beclin1, and a reduction of autophagosome generation in endothelial cells. Moreover, inhibition of autophagy was associated with PI3K/AKT/mTOR and eNOS signaling pathways. Rapamycin attenuated oxLDL/β2GPI/anti-β2GPI complex-induced endothelial inflammation, oxidative stress, and apoptosis, whereas 3-MA alone induced the endothelial injury. Our results suggested that oxLDL/β2GPI/anti-β2GPI complex inhibited endothelial autophagy via PI3K/AKT/mTOR and eNOS signaling pathways and further contributed to endothelial cell dysfunction. Collectively, our findings provided a novel mechanism for vascular endothelial injury in AS patients with an antiphospholipid syndrome (APS) background.

scholarly journals Corneal endothelial cell dysfunction: etiologies and management

2018 ◽  
Vol 10 ◽  
pp. 251584141881580 ◽  
Author(s):  
Sepehr Feizi
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Dysfunction ◽  
Corneal Endothelial Cell ◽  
Endothelial Cell Dysfunction ◽  
Endothelial Keratoplasty ◽  
Corneal Endothelial Cells ◽  
Cell Dysfunction ◽  
Corneal Endothelial Dysfunction

A transparent cornea is essential for the formation of a clear image on the retina. The human cornea is arranged into well-organized layers, and each layer plays a significant role in maintaining the transparency and viability of the tissue. The endothelium has both barrier and pump functions, which are important for the maintenance of corneal clarity. Many etiologies, including Fuchs’ endothelial corneal dystrophy, surgical trauma, and congenital hereditary endothelial dystrophy, lead to endothelial cell dysfunction. The main treatment for corneal decompensation is replacement of the abnormal corneal layers with normal donor tissue. Nowadays, the trend is to perform selective endothelial keratoplasty, including Descemet stripping automated endothelial keratoplasty and Descemet’s membrane endothelial keratoplasty, to manage corneal endothelial dysfunction. This selective approach has several advantages over penetrating keratoplasty, including rapid recovery of visual acuity, less likelihood of graft rejection, and better patient satisfaction. However, the global limitation in the supply of donor corneas is becoming an increasing challenge, necessitating alternatives to reduce this demand. Consequently, in vitro expansion of human corneal endothelial cells is evolving as a sustainable choice. This method is intended to prepare corneal endothelial cells in vitro that can be transferred to the eye. Herein, we describe the etiologies and manifestations of human corneal endothelial cell dysfunction. We also summarize the available options for as well as recent developments in the management of corneal endothelial dysfunction.

Oxidized β2-glycoprotein I induces human dendritic cell maturation and promotes a T helper type 1 response

Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3880-3887 ◽  
Author(s):  
Brigitta Buttari ◽  
Elisabetta Profumo ◽  
Vincenzo Mattei ◽  
Alessandra Siracusano ◽  
Elena Ortona ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Interleukin 1 ◽  
Oxidative Modification ◽  
Interleukin 12 ◽  
Endothelial Cell Dysfunction ◽  
T Helper ◽  
Healthy Human ◽  
Cell Dysfunction ◽  
Glycoprotein I ◽  
Chronic Disorders

The human plasma protein β2-glycoprotein I (β2-GPI) is the most common target for antiphospholipid antibodies associated with thrombotic events in chronic disorders related to endothelial cell dysfunction. Crucial information is needed to clarify why this self-abundant protein is targeted by autoimmune responses. In this study, we investigated whether oxidative modification of β2-GPI, either spontaneous in culture wells or induced by treatment with H2O2, renders this self-protein able to activate immature monocyte-derived dendritic cells (DCs) from healthy human donors. Oxidized β2-GPI caused DCs to mature so that CD83 appeared and CD80, CD86, human leukocyte antigen-D region related (HLA-DR), and CD40 increased. The interaction between oxidized β2-GPI and DCs specifically stimulated these cells to secrete interleukin 12 (IL-12), IL-1β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and IL-10. Oxidized β2-GPI-stimulated DCs had increased allostimulatory ability and primed naive T lymphocytes, thus inducing T helper 1 (Th1) polarization. The interaction between oxidized β2-GPI and DCs involved interleukin-1 receptor associated kinase (IRAK) phosphorylation and nuclear factor κB (NFκB) activation. Pretreatment of β2-GPI with the antioxidant α-tocopherol prevented DC maturation. These findings show that human oxidized β2-GPI, probably by interacting with a member of the Toll-like receptor (TLR) family, causes DCs to mature. Because this key β2-GPI function requires oxidative modification, in several chronic disorders related to endothelial cell dysfunction oxidative stress might trigger the “autoimmune spiral.”

scholarly journals REDD1 is a determinant of low-dose metronomic doxorubicin-elicited endothelial cell dysfunction through downregulation of VEGFR-2/3 expression

2021 ◽  
Author(s):  
Minsik Park ◽  
Joohwan Kim ◽  
Taesam Kim ◽  
Suji Kim ◽  
Wonjin Park ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tumor Angiogenesis ◽  
Low Dose ◽  
Mammalian Target Of Rapamycin ◽  
Growth Factor Receptor ◽  
Metronomic Chemotherapy ◽  
Endothelial Cell Dysfunction ◽  
Lymphatic Endothelial Cells ◽  
Cell Dysfunction

AbstractLow-dose metronomic chemotherapy (LDMC) inhibits tumor angiogenesis and growth by targeting tumor-associated endothelial cells, but the molecular mechanism has not been fully elucidated. Here, we examined the functional role of regulated in development and DNA damage responses 1 (REDD1), an inhibitor of mammalian target of rapamycin complex 1 (mTORC1), in LDMC-mediated endothelial cell dysfunction. Low-dose doxorubicin (DOX) treatment induced REDD1 expression in cultured vascular and lymphatic endothelial cells and subsequently repressed the mRNA expression of mTORC1-dependent translation of vascular endothelial growth factor receptor (Vegfr)-2/3, resulting in the inhibition of VEGF-mediated angiogenesis and lymphangiogenesis. These regulatory effects of DOX-induced REDD1 expression were additionally confirmed by loss- and gain-of-function studies. Furthermore, LDMC with DOX significantly suppressed tumor angiogenesis, lymphangiogenesis, vascular permeability, growth, and metastasis in B16 melanoma-bearing wild-type but not Redd1-deficient mice. Altogether, our findings indicate that REDD1 is a crucial determinant of LDMC-mediated functional dysregulation of tumor vascular and lymphatic endothelial cells by translational repression of Vegfr-2/3 transcripts, supporting the potential therapeutic properties of REDD1 in highly progressive or metastatic tumors.

scholarly journals Early Ascorbic Acid Administration Prevents Vascular Endothelial Cell Damage In Septic Mice

2021 ◽  
Author(s):  
Yutaro Madokoro ◽  
Chinatsu Kamikokuryo ◽  
Shuhei Niiyama ◽  
Takashi Ito ◽  
Satoshi Hara ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Treatment Group ◽  
Vascular Endothelial Cells ◽  
Cell Damage ◽  
Vascular Endothelial Cell ◽  
Vascular Endothelial ◽  
Endothelial Cell Dysfunction ◽  
Endothelial Cell Damage ◽  
Cell Dysfunction ◽  
Late Group

Abstract Ascorbic acid (AsA) therapy for sepsis is thought to have a protective effect on vascular endothelial cells, but the effect of AsA therapy on endothelial cell dysfunction over time and the appropriate timing for AsA administration to demonstrate efficacy is unclear. Septic mice, induced by cecal ligation and puncture (CLP), were examined for the effect of AsA administration (200 mg/kg) on vascular endothelial cell dysfunction at two administration timings: early group (AsA was administered immediately after CLP) and late group (AsA was administered 12 h after CLP). Survival rates were compared between the early and late administration groups, and vascular endothelial cell damage, indicated by the dihydrobiopterin/tetrahydrobiopterin ratio, serum syndecan-1, and endothelial nitric oxide synthase, as well as liver damage, were examined. The early group showed significantly improved survival compared to the non-treatment group (p < 0.05), while the late group showed no improved survival compared to the non-treatment group. Early AsA administration suppressed damage to the vascular endothelial system and liver compared to the non-treatment group. In septic mice, early AsA administration immediately after CLP may have protective effects on vascular endothelial cells, resulting in reduced organ dysfunction and improved survival.

scholarly journals circAFF1 Aggravates Vascular Endothelial Cell Dysfunction Mediated by miR-516b/SAV1/YAP1 Axis

2020 ◽  
Vol 11 ◽  
Author(s):  
Hong-guang Wang ◽  
Hua Yan ◽  
Chen Wang ◽  
Mi-mi Li ◽  
Xin-ze Lv ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Vascular Endothelial Cell ◽  
Vascular Endothelial ◽  
Endothelial Cell Dysfunction ◽  
Cell Dysfunction

scholarly journals miR-101-3p induces vascular endothelial cell dysfunction by targeting tet methylcytosine dioxygenase 2

2020 ◽  
Vol 52 (2) ◽  
pp. 180-191 ◽  
Author(s):  
Qiaoli Chen ◽  
Xiaoye Li ◽  
Lingjun Kong ◽  
Qing Xu ◽  
Zi Wang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Endothelial Cells ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Nuclear Factor Κb ◽  
Vascular Endothelial ◽  
Ros Production ◽  
Cell Dysfunction ◽  
Umbilical Vein Endothelial Cells

Abstract Endothelial cell (EC) dysfunction represents an early key event in atherosclerosis. Recently, MicroRNAs have been demonstrated to regulate EC function. miR-101-3p has been discovered to regulate cell apoptosis and proliferation in cardiovascular diseases. Therefore, the aim of the current study was to clarify whether miR-101-3p regulates the dysfunction of vascular endothelial cells. In this study, the transfection of human umbilical vein endothelial cells (HUVECs) with miR-101-3p mimic induced reactive oxygen species (ROS) production, EC dysfunction, and activated nuclear factor-κB (NF-κB), whereas transfection with miR-101-3p inhibitor alleviated these events. The antioxidant N-acetylcysteine alleviated miR-101-3p-induced EC dysfunction. Moreover, we observed that miR-101-3p inhibited the expression of tet methylcytosine dioxygenase 2 (TET2) at the posttranscriptional level, resulting in increased ROS production and activated NF-κB. TET2 overexpression inhibited ROS production, EC dysfunction, and NF-κB activation in miR-101-3p-transfected HUVECs. These results indicate that miR-101-3p induces EC dysfunction by targeting TET2, which regulates ROS production, EC dysfunction, and NF-κB activation. Taken together, our current study reveals a novel pathway associated with EC dysfunction. The modulation of miR-101-3p and TET2 expression levels may serve as a potential target for therapeutic strategies for atherosclerosis.

Measuring the Direct Effects of Sickle Cell Vaso-Occlusion on Endothelial Cells Using Microfluidic Technology

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 897-897
Author(s):  
David R Myers ◽  
Yumiko Sakurai ◽  
Prasanthi Chappa ◽  
Gilda Barabino ◽  
David R. Archer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Sickle Cell Disease ◽  
Endothelial Function ◽  
Sickle Cell ◽  
Endothelial Cell Dysfunction ◽  
Cell Disease ◽  
Cell Dysfunction ◽  
Sickle Erythrocytes

Abstract Abstract 897 Sickle cell disease is a complex process involving biophysical and biological phenomenon such as microvascular occlusion due to rigid sickle erythrocytes, hemolysis, and aberrant cellular interactions involving endothelial cells and sickle erythrocytes and leukocytes. Indeed, a key aspect of sickle cell pathophysiology is endothelial cell dysfunction. Cardiovascular research in recent years has shown that endothelial cells biologically respond to the local mechanical environment, particularly to the changes in the applied shear stresses (Chiu and Chien, Physiological Reviews, 2011). Interestingly, no studies investigating how the biophysical alterations in sickle cell disease may directly affect endothelial function have been published. The classic view has been that vaso-occlusion is simply due to sickled erythrocytes becoming stuck in microvasculature at low oxygen tensions leading to decreased blood flow and tissue ischemia. However, the mechanical aspects of sickle cell vaso-occlusion themselves, that is, the physical phenomenon of sickling erythrocytes tightly packed in an occluded blood vessel, may directly affect endothelial biology and lead to dysfunction. We hypothesize that these pathologic forces induced by sickling erythrocytes directly lead to dysfunction of endothelial cells, which are mechanosensitive, and contribute to sickle cell pathophysiology. However, these sickling-induced forces and their effects on endothelial cells have been difficult to measure, in part due to a lack of available tools. To that end, we have developed two microfluidic tools to assess the role of sickle-cell vaso-occlusion on endothelial cells. The first device is an in vitro microfluidic platform featuring microchannels the size of post-capillary venules (30 μm) with human endothelial cells cultured within and completely lining the entire inner surface of those microchannels (Figure 1A). This “microvasculature-on-a-chip” enables the visualization of blood cell-endothelial cell interactions during vaso-occlusion under a controlled hemodynamic environment and provides a platform to study the effect of vaso-occlusion on endothelial cells. To date we have characterized this “endothelialized” microfluidic device, showing that endothelial cells are confluent using anti-VE-cadherin immunostaining and adequately generate nitric oxide. Furthermore, we have flowed blood samples from patients with sickle cell disease and found that hydroxyurea treatment both reduces the number of occlusions and increases the mean velocity of the blood traveling through the device, as expected (Figure 1B–E). To decouple whether it is a biochemical or biophysical phenomenon that causes endothelial cell dysfunction during vaso-occlusion, a second micromechanical device was created to quantitatively measure the forces generated by sickling events. The device captures whole blood and will deform outward when forces are applied by the sickle erythrocytes as shown in Figure 2. The membrane above the sickle cells has been coated with 2 μm fluorescent beads which will change focus during deflection. Deflections of one or two beads indicates that a single sickle cell is locally applying force, whereas deflections of large numbers of beads indicates that the cells are collectively applying a pressure to the membrane. The device has been fully fabricated and loaded with blood cells. An accompanying experimental setup enabling the deoxygenation of the device coupled with microscopy has also been created and preliminary tests show successful deoxygenation of sickle erythrocytes from patients with hemoglobin SS disease and the Berkeley sickle cell mouse model. By combining insights gained from each device, future work will determine how the mechanical process of sickling and vaso-occlusion directly affect endothelial function and will lead to a new understanding of sickle cell pathophysiology. Sickle cell vaso-occlusion will be induced in the “endothelialized” microfluidic device while monitoring nitric oxide production and the upregulation of inflammatory markers, such as adhesion molecules and free radicals. The second device will provide quantitative numbers of forces produced by sickling erythrocytes, leading to experiments in which these forces are applied to endothelial cells while monitoring the same metrics. Disclosures: No relevant conflicts of interest to declare.

Increased Erythrocyte Rigidity Is Sufficient to Cause Endothelial Dysfunction in Sickle Cell Disease

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 818-818 ◽  
Author(s):  
Robert Mannino ◽  
David R Myers ◽  
Yumiko Sakurai ◽  
Russell E. Ware ◽  
Gilda Barabino ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Dysfunction ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Adhesion Molecule ◽  
Endothelial Cell Dysfunction ◽  
Cell Disease ◽  
Cell Dysfunction ◽  
Sickle Erythrocytes

Abstract Abstract 818 Endothelial dysfunction is a major component of sickle cell disease (SCD) pathophysiology. Interestingly, previous cardiovascular research has definitively shown that endothelial cells biologically respond to mechanical forces and aberrations in these forces cause endothelial dysfunction via pro-inflammatory pathways that are also involved in SCD. While endothelial dysfunction in SCD has been well characterized biologically, little research has focused on the direct biophysical effects of SCD blood on endothelium. As endothelial cells are in constant contact with flowing “stiffened” sickle erythrocytes, we propose that the direct mechanical interactions between the physically altered sickle erythrocytes and endothelial cells are an additional cause of endothelial dysfunction in SCD (Figure 1A). Endothelial dysfunction in SCD is thought to be caused by the downstream effects of vaso-occlusion and/or hemolysis. Our laboratory has recently developed and published a description of an in vitro microvasculature model comprised of endothelial cells that are cultured throughout the entire 3D inner surface of a microfluidic system designed for investigating cellular interactions in hematologic diseases (Tsai, et al, JCI, 2012), (Figure 1B-D). This microvasculature-on-a-chip recapitulates an ensemble of physiological processes and biophysical properties, including adhesion molecule expression, blood cell-endothelial cell interactions, cell deformability, cell size/shape, microvascular geometry, hemodynamics, and oxygen levels (Myers et al. JoVE, 2012), all of which may contribute to endothelial dysfunction in SCD. We hypothesize that the mechanical interactions between sickle erythrocytes and endothelial cells alone are sufficientto cause endothelial dysfunction in our microvasculature-on-a-chip. To test our hypothesis, we flowed different suspensions of healthy red blood cells (RBCs), and stiffened RBCs, through our microvasculature on a chip cultured with HUVECs. We suspended fresh human RBCs in media at a low hematocrit recapitulating the anemic conditions typically seen in SCD patients as a control. The experimental conditions used the same solution as the control, but also contained glutaraldehyde-stiffened RBCs, which are of the same stiffness as irreversibly sickled cells (ISCs), at approximately the same concentrations as ISCs in SCD patients. The stiffened RBC suspension was washed multiple times to eliminate all traces of glutaraldehyde and to ensure that any endothelial cell dysfunction in our system was due to mechanical effects between the endothelium and RBCs. After 4 hours of perfusion, the number of occlusions in our microsystem was counted and the cells were fixed and stained for Vascular Cell Adhesion Molecule 1 (VCAM-1). VCAM-1 been shown to be a marker of endothelial cell dysfunction and is a biomarker for severe vasculopathy in SCD (Dworkis, Am J Hematol, 2011). Immunofluorescence staining in our microsystem confirmed that VCAM1 is upregulated (Figure 2) in HUVECs when exposed to flowing stiffened RBCs compared to control RBCs. VCAM-1 upregulation appears to be diffuse throughout the length of the device. After experimentation, endothelial cells in our system can be isolated for further RT-PCR or microarray analysis. As such, ongoing work involves investigating and quantifying the expression of other pro-inflammatory molecules to elucidate the underlying mechanisms of this biomechanical process involving RBCs and endothelial cells. Additional experiments complementary experiments using endothelial cells from other anatomic areas, SCD patient samples, and murine SCD models are also underway. Our data indicates that purely physical interactions between endothelial cells and stiffened RBCs are sufficient to cause some degree of endothelial dysfunction, even in the absence of vaso-occlusion, ischemia, or oxidative stress due to hemolysis. As sickle RBCs and ISCs are constantly circulating in the blood of SCD patients, our results have profound implications for SCD pathophysiology and may help explain why SCD patients develop chronic diffuse vasculopathy over time. Disclosures: No relevant conflicts of interest to declare.

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