Differential effect of MLC kinase in TNF-α-induced endothelial cell apoptosis and barrier dysfunction

2001 ◽  
Vol 280 (6) ◽  
pp. L1168-L1178 ◽  
Author(s):  
Irina Petrache ◽  
Alexander D. Verin ◽  
Michael T. Crow ◽  
Anna Birukova ◽  
Feng Liu ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Electrical Resistance ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Endothelial Cell Apoptosis ◽  
Gap Formation ◽  
Barrier Dysfunction ◽  
Tnf Α ◽  
Mlc Phosphorylation

Tumor necrosis factor (TNF)-α is released in acute inflammatory lung syndromes linked to the extensive vascular dysfunction associated with increased permeability and endothelial cell apoptosis. TNF-α induced significant decreases in transcellular electrical resistance across pulmonary endothelial cell monolayers, reflecting vascular barrier dysfunction (beginning at 4 h and persisting for 48 h). TNF-α also triggered endothelial cell apoptosis beginning at 4 h, which was attenuated by the caspase inhibitor Z-Val-Ala-Asp-fluoromethylketone. Exploring the involvement of the actomyosin cytoskeleton in these important endothelial cell responses, we determined that TNF-α significantly increased myosin light chain (MLC) phosphorylation, with prominent stress fiber and paracellular gap formation, which paralleled the onset of decreases in transcellular electrical resistance and enhanced apoptosis. Reductions in MLC phosphorylation by the inhibition of either MLC kinase (ML-7, cholera toxin) or Rho kinase (Y-27632) dramatically attenuated TNF-α-induced stress fiber formation, indexes of apoptosis, and caspase-8 activity but not TNF-α-induced barrier dysfunction. These studies indicate a central role for the endothelial cell cytoskeleton in TNF-α-mediated apoptosis, whereas TNF-α-induced vascular permeability appears to evolve independently of contractile tension generation.

scholarly journals Mechanisms of sodium fluoride-induced endothelial cell barrier dysfunction: role of MLC phosphorylation

2001 ◽  
Vol 281 (6) ◽  
pp. L1472-L1483 ◽  
Author(s):  
Peiyi Wang ◽  
Alexander D. Verin ◽  
Anna Birukova ◽  
Lydia I. Gilbert-McClain ◽  
Keri Jacobs ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Phosphatase Activity ◽  
Fiber Formation ◽  
Dominant Negative ◽  
Actin Stress Fiber ◽  
Gap Formation ◽  
Barrier Dysfunction ◽  
Transient Activation ◽  
Mlc Phosphorylation

NaF, a potent G protein activator and Ser/Thr phosphatase inhibitor, significantly increased albumin permeability and decreased transcellular electrical resistance (TER), indicating endothelial cell (EC) barrier impairment. EC barrier dysfunction induced by NaF was accompanied by the development of actin stress fibers, intercellular gap formation, and significant time-dependent increases in myosin light chain (MLC) phosphorylation. However, despite rapid, albeit transient, activation of Ca2+/calmodulin-dependent MLC kinase (MLCK), the specific MLCK inhibitor ML-7 failed to affect NaF-induced MLC phosphorylation, actin cytoskeletal rearrangement, and reductions in TER, suggesting a limited role of MLCK in NaF-induced EC activation. In contrast, strategies to reduce Rho (C3 exoenzyme or toxin B) or to inhibit Rho-associated kinase (Y-27632 or dominant/negative RhoK) dramatically reduced MLC phosphorylation and actin stress fiber formation and significantly attenuated NaF-induced EC barrier dysfunction. Consistent with this role for RhoK activity, NaF selectively inhibited myosin-specific phosphatase activity, whereas the total Ser/Thr phosphatase activity remained unchanged. These data strongly suggest that MLC phosphorylation, mediated primarily by RhoK, and not MLCK, participates in NaF-induced EC actin cytoskeletal changes and barrier dysfunction.

scholarly journals Microtubule disassembly increases endothelial cell barrier dysfunction: role of MLC phosphorylation

2001 ◽  
Vol 281 (3) ◽  
pp. L565-L574 ◽  
Author(s):  
Alexander D. Verin ◽  
Anna Birukova ◽  
Peiyi Wang ◽  
Feng Liu ◽  
Patrice Becker ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Electrical Resistance ◽  
Rho Gtpase ◽  
Dependent Manner ◽  
Transendothelial Electrical Resistance ◽  
Barrier Dysfunction ◽  
Microtubule Disruption ◽  
Barrier Regulation ◽  
Mlc Phosphorylation

Endothelial cell (EC) barrier regulation is critically dependent on cytoskeletal components (microfilaments and microtubules). Because several edemagenic agents induce actomyosin-driven EC contraction tightly linked to myosin light chain (MLC) phosphorylation and microfilament reorganization, we examined the role of microtubule components in bovine EC barrier regulation. Nocodazole or vinblastine, inhibitors of microtubule polymerization, significantly decreased transendothelial electrical resistance in a dose-dependent manner, whereas pretreatment with the microtubule stabilizer paclitaxel significantly attenuated this effect. Decreases in transendothelial electrical resistance induced by microtubule disruption correlated with increases in lung permeability in isolated ferret lung preparations as well as with increases in EC stress fiber content and MLC phosphorylation. The increases in MLC phosphorylation were attributed to decreases in myosin-specific phosphatase activity without significant increases in MLC kinase activity and were attenuated by paclitaxel or by several strategies (C3 exotoxin, toxin B, Rho kinase inhibition) to inhibit Rho GTPase. Together, these results suggest that microtubule disruption initiates specific signaling pathways that cross talk with microfilament networks, resulting in Rho-mediated EC contractility and barrier dysfunction.

scholarly journals Effects of down-regulation of microRNA-23a on TNF-α-induced endothelial cell apoptosis through caspase-dependent pathways

2011 ◽  
Vol 93 (4) ◽  
pp. 623-632 ◽  
Author(s):  
Wei Ruan ◽  
Jun-mei Xu ◽  
Suo-bei Li ◽  
Ling-qing Yuan ◽  
Ru-ping Dai
Keyword(s):  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Endothelial Cell Apoptosis ◽  
Down Regulation ◽  
Tnf Α

Direct ANP inhibition of hypoxia-induced inflammatory pathways in pulmonary microvascular and macrovascular endothelial monolayers

2005 ◽  
Vol 288 (5) ◽  
pp. L849-L859 ◽  
Author(s):  
D. C. Irwin ◽  
M. C. Tissot van Patot ◽  
A. Tucker ◽  
R. Bowen
Keyword(s):  
Endothelial Cell ◽  
P38 Mapk ◽  
Umbilical Vein ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Mitogen Activated Protein Kinase ◽  
Actin Stress Fiber ◽  
Vascular Leak ◽  
Stress Fiber Formation ◽  
Tnf Α

Atrial natriuretic peptide (ANP) has been shown to reduce hypoxia-induced pulmonary vascular leak in vivo, but no explanation of a mechanism has been offered other than its vasodilatory and natriuretic actions. Recently, data have shown that ANP can protect endothelial barrier functions in TNF-α-stimulated human umbilical vein endothelial cells. Therefore, we hypothesized that ANP actions would inhibit pulmonary vascular leak by inhibition of TNF-α secretion and F-actin formation. Bovine pulmonary microvascular (MVEC) and macrovascular endothelial cell (LEC) monolayers were stimulated with hypoxia, TNF-α, or bacterial endotoxin (LPS) in the presence or absence of ANP, and albumin flux, NF-κB activation, TNF-α secretion, p38 mitogen-activated protein kinase (MAPK), and F-actin (stress fiber) formation were assessed. In Transwell cultures, ANP reduced hypoxia-induced permeability in MVEC and TNF-α-induced permeability in MVEC and LEC. ANP inhibited hypoxia and LPS increased NF-κB activation and TNF-α synthesis in MVEC and LEC. Hypoxia decreased activation of p38 MAPK in MVEC but increased activation of p38 MAPK and stress fiber formation in LEC; TNF-α had the opposite effect. ANP inhibited an activation of p38 MAPK in MVEC or LEC. These data indicate that in endothelial cell monolayers, hypoxia activates a signal cascade analogous to that initiated by inflammatory agents, and ANP has a direct cytoprotective effect on the pulmonary endothelium other than its vasodilatory and natriuretic properties. Furthermore, our data show that MVEC and LEC respond differently to hypoxia, TNF-α-stimulation, and ANP treatment.

scholarly journals Endothelial cell apoptosis in brown adipose tissue of rats induced by hyperinsulinaemia: the possible role of TNF-α

2011 ◽  
Vol 55 (4) ◽  
pp. 34 ◽  
Author(s):  
M. Markelic ◽  
K. Velickovic ◽  
I. Golic ◽  
V. Otasevic ◽  
A. Stancic ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Endothelial Cell ◽  
Brown Adipose Tissue ◽  
Cell Apoptosis ◽  
Endothelial Cell Apoptosis ◽  
Brown Adipose ◽  
Tnf Α

Regulation of nicotine-induced apoptosis of pulmonary artery endothelial cells by treatment of N-acetylcysteine and vitamin E

2007 ◽  
Vol 26 (7) ◽  
pp. 595-602 ◽  
Author(s):  
R. Demiralay ◽  
N. Gürsan ◽  
H. Erdem
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vitamin E ◽  
Pulmonary Artery ◽  
Cell Apoptosis ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Control Group ◽  
Endothelial Cell Apoptosis ◽  
Antioxidant Agents ◽  
Tnf Α

This study investigated the frequency of apoptosis in rat pulmonary artery endothelial cells after intraperitoneal nicotine injection, examining the roles of the inflammatory markers myeloperoxidase (MPO), tumour necrosis factor alpha (TNF-α ), and vascular endothelial growth factor (VEGF) in nicotine-induced vascular damage and the protective effects of two known antioxidant agents, N-acetylcysteine (NAC) and vitamin E. Female Wistar rats were divided into four groups, each composed of nine rats: negative control group, positive control group, NACtreated group (500 mg/kg), and vitamin E-treated group (500 mg/kg). Nicotine was intraperitoneally injected at a dosage of 0.6 mg/kg for 21 days. Following nicotine injection, the antioxidants were administered orally; treatment was continued until the rats were killed. Lung tissue samples were stained with hematoxylin-eosin (H&E) for histopathological assessments. Apoptosis level in endothelial cells was determined by using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick endlabelling) method. Staining of cytoplasmic TNF-α and VEGF in endothelial cells, and perivascular MPO activity were evaluated by immunohistochemistry. The treatments with NAC and vitamin E significantly reduced the rate of nicotine-induced endothelial cell apoptosis. NAC and vitamin E significantly reduced the increases in the local production of TNF-α and VEGF, and perivascular MPO activity. This findings suggest that NAC can be as effective as vitamin E in protecting against nicotine-induced endothelial cell apoptosis. Human & Experimental Toxicology (2007) 26: 595—602.

Effects and mechanism of arachidonic acid against TNF-α induced apoptosis of endothelial cells

2020 ◽  
pp. 1-7
Author(s):  
Ji-Xiong Chen ◽  
Xiao-Yan Huang ◽  
Ping Wang ◽  
Wen-Ting Lin ◽  
Wen-Xing Xu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Umbilical Vein ◽  
Arachidonic Acid Metabolite ◽  
Apoptotic Cells ◽  
Endothelial Cell Apoptosis ◽  
Tnf Α

This study aimed to investigate the effects of arachidonic acid metabolite epoxyeicosatrienoic acid (EETs) in the apoptosis of endothelial cells induced by tumor necrosis factor-alpha (TNF-α). After human umbilical vein endothelial cells were cultured, TNF-α/ActD, 14, 15-EET, and HMR-1098 were added, respectively, into the culture medium. The apoptosis level of endothelial cells was detected by flow cytometry. After TNF-α/ActD induced endothelial cell apoptosis, flow cytometry staining showed that endothelial cell apoptosis increased significantly, and the apoptotic cells were significantly reduced after the addition of 14, 15-EET. However, the apoptotic cells significantly increased after the addition of HMR-1098. Western Blot results showed that the phosphorylation levels of LC3-II and AMPK were increased after TNF-α/ActD induction, and the increase was noticeable after the addition of 14, 15-EET. However, the phosphorylation levels of LC3-II and AMPK significantly decreased after the addition of HMR-1098. The activity of Caspase-8 and -9 decreased significantly after the addition of 14, 15-EET but increased after the addition of HMR-1098. Arachidonic acid can inhibit TNF-α induced endothelial cell apoptosis by upregulating autophagy.

Sign in / Sign up

Export Citation Format

Share Document