scholarly journals Endothelium as target for large-conductance calcium-activated potassium channel openers.

2009 ◽  
Vol 56 (3) ◽  
Author(s):  
Antoni Wrzosek
Keyword(s):  
Endothelial Cells ◽  
Potassium Channels ◽  
Potassium Channel ◽  
Plasma Membranes ◽  
Inflammatory Responses ◽  
Critical Role ◽  
The Body ◽  
Pharmacological Intervention ◽  
Ca Channels ◽  
Calcium Activated Potassium Channels

The endothelium is a highly active organ responsible for vasculatory tone and structure, angiogenesis, as well as hemodynamic, humoral, and inflammatory responses. The endothelium is constantly exposed to blood flow, sheer stress and tension. Endothelial cells are present as a vasculature in every tissue of the body and react to and control its microenvironment. A variety of ion channels are present in the plasma membranes of endothelial cells. These include potassium channels such as inwardly rectifying potassium (K(ir)) channels, voltage-dependent (K(v)) channels, ATP-regulated potassium (K(ATP)) channels and three types of calcium-activated potassium channels (K(Ca)), the large (BK(Ca)), intermediate (IK(Ca)), and small (SK(Ca)) -conductance potassium channels. Potassium current plays a critical role in action potentials in excitable cells, in setting the resting membrane potential, and in regulating neurotransmitter release. Mitochondrial isoforms of potassium channel contribute to the cytoprotection of endothelial cells. Prominent among potassium channels are families of calcium-activated potassium channels, and especially large-conductance calcium-activated potassium channels. The modulation of BK(Ca) channels, which are voltage- and calcium-dependent, has been intensively studied. The BK(Ca) channels show large expression dynamics in endothelial cells and tissue-specific expression of large numbers of alternatively spliced isoforms. In this review, a few examples of the modulatory mechanisms and physiological consequences of the expression of BK(Ca) channels are discussed in relation to potential targets for pharmacological intervention.

scholarly journals Reversal of the Inflammatory Responses in Fabry Patient iPSC-Derived Cardiovascular Endothelial Cells by CRISPR/Cas9-Corrected Mutation

2021 ◽  
Vol 22 (5) ◽  
pp. 2381
Author(s):  
Hui-Yung Song ◽  
Yi-Ping Yang ◽  
Yueh Chien ◽  
Wei-Yi Lai ◽  
Yi-Ying Lin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Responses ◽  
Late Onset ◽  
Critical Role ◽  
Vascular Complications ◽  
Digital Pcr ◽  
Mapk Signaling ◽  
Autophagic Flux ◽  
Fabry Patient ◽  
Genomic Editing

The late-onset type of Fabry disease (FD) with GLA IVS4 + 919G > A mutation has been shown to lead to cardiovascular dysfunctions. In order to eliminate variations in other aspects of the genetic background, we established the isogenic control of induced pluripotent stem cells (iPSCs) for the identification of the pathogenetic factors for FD phenotypes through CRISPR/Cas9 genomic editing. We adopted droplet digital PCR (ddPCR) to efficiently capture mutational events, thus enabling isolation of the corrected FD from FD-iPSCs. Both of these exhibited the characteristics of pluripotency and phenotypic plasticity, and they can be differentiated into endothelial cells (ECs). We demonstrated the phenotypic abnormalities in FD iPSC-derived ECs (FD-ECs), including intracellular Gb3 accumulation, autophagic flux impairment, and reactive oxygen species (ROS) production, and these abnormalities were rescued in isogenic control iPSC-derived ECs (corrected FD-ECs). Microarray profiling revealed that corrected FD-derived endothelial cells reversed the enrichment of genes in the pro-inflammatory pathway and validated the downregulation of NF-κB and the MAPK signaling pathway. Our findings highlighted the critical role of ECs in FD-associated vascular dysfunctions by establishing a reliable isogenic control and providing information on potential cellular targets to reduce the morbidity and mortality of FD patients with vascular complications.

Disruption of endothelial Pfkfb3 ameliorates diet-induced murine insulin resistance

2021 ◽  
Author(s):  
Qiuhua Yang ◽  
Jiean Xu ◽  
Qian Ma ◽  
Zhiping Liu ◽  
Yaqi Zhou ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Endothelial Cells ◽  
High Fat Diet ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Endothelial Inflammation ◽  
Glucose Clearance ◽  
Deficient Mice

Overnutrition-induced endothelial inflammation plays a crucial role in high fat diet (HFD)-induced insulin resistance in animals. Endothelial glycolysis plays a critical role in endothelial inflammation and proliferation, but its role in diet-induced endothelial inflammation and subsequent insulin resistance has not been elucidated. PFKFB3 is a critical glycolytic regulator, and its increased expression has been observed in adipose vascular endothelium of C57BL/6J mice fed with HFD in vivo, and in palmitate (PA)-treated primary human adipose microvascular endothelial cells (HAMECs) in vitro. We generated mice with Pfkfb3 deficiency selective for endothelial cells to examine the effect of endothelial Pfkfb3 in endothelial inflammation in metabolic organs and in the development of HFD-induced insulin resistance. EC Pfkfb3-deficient mice exhibited mitigated HFD-induced insulin resistance, including decreased body weight and fat mass, improved glucose clearance and insulin sensitivity, and alleviated adiposity and hepatic steatosis. Mechanistically, cultured PFKFB3 knockdown HAMECs showed decreased NF-κB activation induced by PA, and consequent suppressed adhesion molecule expression and monocyte adhesion. Taken together, these results demonstrate that increased endothelial PFKFB3 expression promotes diet-induced inflammatory responses and subsequent insulin resistance, suggesting that endothelial metabolic alteration plays an important role in the development of insulin resistance.

scholarly journals Invasive Phenotype of Candida albicans Affects the Host Proinflammatory Response to Infection

2005 ◽  
Vol 73 (8) ◽  
pp. 4588-4595 ◽  
Author(s):  
C. C. Villar ◽  
H. Kashleva ◽  
A. P. Mitchell ◽  
A. Dongari-Bagtzoglou
Keyword(s):  
Endothelial Cells ◽  
Candida Albicans ◽  
Proinflammatory Cytokines ◽  
Proinflammatory Cytokine ◽  
Inflammatory Responses ◽  
Gene Knockout ◽  
Critical Role ◽  
Host Cells ◽  
Proinflammatory Response ◽  
Cytokine Responses

ABSTRACT Candida albicans is a major opportunistic pathogen in immunocompromised patients. Production of proinflammatory cytokines by host cells in response to C. albicans plays a critical role in the activation of immune cells and final clearance of the organism. Invasion of host cells and tissues is considered one of the virulence attributes of this organism. The purpose of this study was to investigate whether the ability of C. albicans to invade host cells and tissues affects the proinflammatory cytokine responses by epithelial and endothelial cells. In this study we used the invasion-deficient RIM101 gene knockout strain DAY25, the highly invasive strain SC5314, and highly invasive RIM101-complemented strain DAY44 to compare the proinflammatory cytokine responses by oral epithelial or endothelial cells. Using a high-throughput approach, we found both qualitative and quantitative differences in the overall inflammatory responses to C. albicans strains with different invasive potentials. Overall, the highly invasive strains triggered higher levels of proinflammatory cytokines in host cells than the invasion-deficient mutant triggered. Significant differences compared to the attenuated mutant were noted in interleukin-1α (IL-1α), IL-6, IL-8, and tumor necrosis factor alpha in epithelial cells and in IL-6, growth-related oncogene, IL-8, monocyte chemoattractant protein 1 (MCP-1), MCP-2, and granulocyte colony-stimulating factor in endothelial cells. Our results indicate that invasion of host cells and tissues by C. albicans enhances the host proinflammatory response to infection.

scholarly journals The cell-type specific uptake of polymer-coated or micelle-embedded QDs and SPIOs does not provoke an acute pro-inflammatory response in the liver

2014 ◽  
Vol 5 ◽  
pp. 1432-1440 ◽  
Author(s):  
Markus Heine ◽  
Alexander Bartelt ◽  
Oliver T Bruns ◽  
Denise Bargheer ◽  
Artur Giemsa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Side Effects ◽  
Kupffer Cells ◽  
Biomedical Applications ◽  
Inflammatory Responses ◽  
The Body ◽  
Wild Type ◽  
Liver Sinusoidal Endothelial Cells ◽  
Necrosis Factor Alpha ◽  
Lipid Micelles

Semiconductor quantum dots (QD) and superparamagnetic iron oxide nanocrystals (SPIO) have exceptional physical properties that are well suited for biomedical applications in vitro and in vivo. For future applications, the direct injection of nanocrystals for imaging and therapy represents an important entry route into the human body. Therefore, it is crucial to investigate biological responses of the body to nanocrystals to avoid harmful side effects. In recent years, we established a system to embed nanocrystals with a hydrophobic oleic acid shell either by lipid micelles or by the amphiphilic polymer poly(maleic anhydride-alt-1-octadecene) (PMAOD). The goal of the current study is to investigate the uptake processes as well as pro-inflammatory responses in the liver after the injection of these encapsulated nanocrystals. By immunofluorescence and electron microscopy studies using wild type mice, we show that 30 min after injection polymer-coated nanocrystals are primarily taken up by liver sinusoidal endothelial cells. In contrast, by using wild type, Ldlr -/- as well as Apoe -/- mice we show that nanocrystals embedded within lipid micelles are internalized by Kupffer cells and, in a process that is dependent on the LDL receptor and apolipoprotein E, by hepatocytes. Gene expression analysis of pro-inflammatory markers such as tumor necrosis factor alpha (TNFα) or chemokine (C-X-C motif) ligand 10 (Cxcl10) indicated that 48 h after injection internalized nanocrystals did not provoke pro-inflammatory pathways. In conclusion, internalized nanocrystals at least in mouse liver cells, namely endothelial cells, Kupffer cells and hepatocytes are at least not acutely associated with potential adverse side effects, underlining their potential for biomedical applications.

scholarly journals Necroptosis in Pulmonary Diseases: A New Therapeutic Target

2021 ◽  
Vol 12 ◽  
Author(s):  
Lingling Wang ◽  
Ling Zhou ◽  
Yuhao Zhou ◽  
Lu Liu ◽  
Weiling Jiang ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membranes ◽  
Inflammatory Responses ◽  
Neurological Diseases ◽  
Kinase Domain ◽  
The Body ◽  
Interacting Protein ◽  
Membrane Rupture ◽  
Regulated Cell Death ◽  
Scientific Attention

In the past decades, apoptosis has been the most well-studied regulated cell death (RCD) that has essential functions in tissue homeostasis throughout life. However, a novel form of RCD called necroptosis, which requires receptor-interacting protein kinase-3 (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), has recently been receiving increasing scientific attention. The phosphorylation of RIPK3 enables the recruitment and phosphorylation of MLKL, which oligomerizes and translocates to the plasma membranes, ultimately leading to plasma membrane rupture and cell death. Although apoptosis elicits no inflammatory responses, necroptosis triggers inflammation or causes an innate immune response to protect the body through the release of damage-associated molecular patterns (DAMPs). Increasing evidence now suggests that necroptosis is implicated in the pathogenesis of several human diseases such as systemic inflammation, respiratory diseases, cardiovascular diseases, neurodegenerative diseases, neurological diseases, and cancer. This review summarizes the emerging insights of necroptosis and its contribution toward the pathogenesis of lung diseases.

The Role of VWF In BBB Permeability Associated with Hypoxia/Reoxygenation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2102-2102
Author(s):  
Georgette L. Suidan ◽  
Simon F. De Meyer ◽  
Alexander Brill ◽  
Stephen M. Cifuni ◽  
Denisa D. Wagner
Keyword(s):  
Endothelial Cells ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
The Body ◽  
Wild Type ◽  
Junction Protein ◽  
Bbb Permeability ◽  
Deficient Mice ◽  
Hypoxia Reoxygenation

Abstract Abstract 2102 Aberrant blood brain barrier (BBB) permeability is a hallmark pathology in many diseases of the central nervous system (CNS) including hypoxia, epilepsy, multiple sclerosis and ischemic stroke. Generalized hypoxia is a pathological condition in which the body as a whole is deprived of adequate oxygen supply. Hypoxia occurs in healthy people when they ascend to high altitudes, where it can cause altitude sickness, often manifested by headache, leading to potentially fatal complications such as high altitude cerebral edema (HACE). Hypoxia followed by reoxygenation (H/R) is also commonly used as a model to investigate pathology associated with ischemia/reperfusion as the latter condition is present in several disease states including stroke. In animal models, H/R has been shown to cause tight junction protein abnormalities, increased BBB paracellular permeability and edema. von Willebrand Factor (VWF) is a glycoprotein that is synthesized exclusively by endothelial cells and megakaryocytes. Endothelial cell-derived VWF is secreted constitutively and stored in Weibel-Palade bodies (WPB) from where it is released by regulated secretion into the plasma and subendothelium in response to endothelial activation. It has been demonstrated in vitro that exposure of cultured endothelial cells to hypoxia results in WPB exocytosis and VWF secretion. While it is known that VWF is expressed abundantly by cerebral endothelial cells, very little is known about the role of VWF in endothelial biology, particularly, in regulation of the BBB under stressful conditions. Several studies have shown that VWF protein is up regulated in plasma of patients with several neurological conditions involving BBB disruption such as stroke, severe head injury, cerebral malaria and cerebral venous sinus thrombosis. As it is known that C57BL/6 (wild-type) mice have increased BBB permeability induced by H/R, we investigated the status of BBB integrity in VWF-deficient mice (also on the C57BL/6 background). For these experiments, we used a mouse model of normobaric hypoxia (24 hours of 6% oxygen) followed by reoxygenation (1 hour ~21% oxygen). VWF antigen levels were measured by ELISA and BBB permeability was assessed by quantification of Evan's blue dye leakage into the brain. Our data indicate that plasma VWF levels in wild-type mice are significantly increased after hypoxia when compared to normoxic controls. Upon comparison with wild-type mice, we have determined that VWF-deficient mice have significantly less BBB permeability after H/R suggesting that VWF plays a role in BBB integrity under stressful conditions. We have previously reported that VWF-deficient mice have a defect in regulated P-selectin secretion (Denis et al., PNAS, 2001). To determine if the maintenance of BBB integrity found in VWF-deficient mice was due to lack of P-selectin we utilized an aptamer which inhibits P-selectin (Archemix). Inhibition of P-selectin in wild-type animals resulted in similar BBB permeability when compared to controls. Our findings suggest a critical role for VWF in BBB permeability after hypoxia/reoxygenation that is independent of P-selectin. Disclosures: No relevant conflicts of interest to declare.

Calcium-Activated Potassium Conductances in Retinal Ganglion Cells of the Ferret

1998 ◽  
Vol 79 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Guo-Yong Wang ◽  
David W. Robinson ◽  
Leo M. Chalupa
Keyword(s):  
Potassium Channels ◽  
Potassium Channel ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Membrane Properties ◽  
Retinal Ganglion ◽  
Wide Range ◽  
Potassium Conductances ◽  
Calcium Activated Potassium Channels ◽  
Calcium Activated Potassium Channel

Wang, Guo-Yong, David W. Robinson, and Leo M. Chalupa. Calcium-activated potassium conductances in retinal ganglion cells of the ferret. J. Neurophysiol. 79: 151–158, 1998. Patch-clamp recordings were made from isolated and intact retinal ganglion cells (RGCs) of the ferret to examine the calcium-activated potassium channels expressed by these neurons and to determine their functional role in the generation of spikes and spiking patterns. Single-channel recordings from isolated neurons revealed the presence of two calcium-sensitive potassium channels that had conductances of 118 and 22 pS. The properties of these two channels were shown to be similar to those ascribed to the large-conductance calcium-activated potassium channel (BKCa) and small-conductance calcium-activated potassium channel (SKCa) channels in other neurons. Whole cell recordings from isolated RGCs showed that apamin and charybdotoxin (CTX), specific blockers of the SKCa and BKCa channels, respectively, resulted in a shortening of the time to threshold and a reduction in the hyperpolarization after the spike. Addition of these blockers also resulted in a significant increase in spike frequency over a wide range of maintained depolarizations. Similar effects of apamin and CTX were observed during current-clamp recordings from intact alpha and beta ganglion cells, morphologically identified after Lucifer yellow filling. About 20% of these neurons did not exhibit a sensitivity to either blocker, suggesting the presence of functionally distinct subgroups of alpha and beta RGCs on the basis of their intrinsic membrane properties. The expression of these calcium-activated potassium channels in the majority of alpha and beta cells provides a means by which the activity of these output neurons could be modulated by retinal neurochemicals.

Large-conductance calcium-activated potassium channels in purkinje cell plasma membranes are clustered at sites of hypolemmal microdomains

2009 ◽  
Vol 515 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Walter A. Kaufmann ◽  
Francesco Ferraguti ◽  
Yugo Fukazawa ◽  
Yu Kasugai ◽  
Ryuichi Shigemoto ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Purkinje Cell ◽  
Plasma Membranes ◽  
Cell Plasma ◽  
Calcium Activated Potassium Channels

scholarly journals Lysophosphatidylcholine impairs endothelial barrier function through the G protein-coupled receptor GPR4

2006 ◽  
Vol 291 (1) ◽  
pp. L91-L101 ◽  
Author(s):  
Jing Qiao ◽  
Fei Huang ◽  
Ram P. Naikawadi ◽  
Kwang S. Kim ◽  
Tamer Said ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
G Protein ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Fiber Formation ◽  
Endothelial Barrier ◽  
Barrier Dysfunction ◽  
Small Interference Rna ◽  
Endothelial Barrier Dysfunction ◽  
G Protein Coupled

Abundant evidence indicates that lysophosphatidylcholine (LPC) is proinflammatory and atherogenic. In the vascular endothelium, LPC increases permeability and expression of proinflammatory molecules such as adhesion molecules and cytokines. Yet, mechanisms by which LPC mediates these activities remain unclear and controversial. Recent evidence implicates involvement of a novel subfamily of G protein-coupled receptors (GPR4, G2A, OGR1, and TDAG8) that are sensitive to lysolipids and protons. We previously reported that one of these receptors, GPR4, is selectively expressed by a variety of endothelial cells and therefore hypothesize that the LPC-stimulated endothelial barrier dysfunction is mediated through GPR4. We developed a peptide Ab against GPR4 that detected GPR4 expression in transfected COS 7 cells and endogenous GPR4 expression in endothelial cells by Western blot. Endothelial cells infected with a retrovirus containing small interference RNA (siRNA) to GPR4 resulted in 40–50% decreased GPR4 expression, which corresponded with partial prevention of the LPC-induced 1) decrease in transendothelial resistance, 2) stress fiber formation, and 3) activation of RhoA. Furthermore, coexpression of the siRNA-GPR4 with a siRNA-resistant mutant GPR4 fully restored the LPC-induced resistance decrease. However, extracellular pH of <7.4 did not alter baseline or LPC-stimulated resistances. The results provide strong evidence that the LPC-mediated endothelial barrier dysfunction is regulated by endogenous GPR4 in endothelial cells and suggest that GPR4 may play a critical role in the inflammatory responses activated by LPC.

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