scholarly journals Interleukin-6 Trans-Signaling Mediated Regulation of Paracellular Permeability in Human Retinal Endothelial Cells

2021 ◽  
Vol 1 (2) ◽  
pp. 137-153
Author(s):  
Joshua Glass ◽  
Rebekah Robinson ◽  
Tae-Jin Lee ◽  
Ashok Sharma ◽  
Shruti Sharma
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Diabetic Retinopathy ◽  
Interleukin 6 ◽  
Vascular Inflammation ◽  
Paracellular Permeability ◽  
Blood Retinal Barrier ◽  
Retinal Endothelial Cells ◽  
Expression Of Genes ◽  
Signaling Activation

Long-term hyperglycemia-mediated oxidative stress and inflammation lead to the blood-retinal barrier (BRB) dysfunction and increased vascular permeability associated with diabetic retinopathy (DR). Interleukin-6 (IL-6) is one of the primary mediators of retinal vascular inflammation. IL-6 signaling through its membrane-bound IL-6 receptor is known as classical signaling, and through a soluble IL-6 receptor (sIL-6R) is known as trans-signaling. Increasing evidence suggests that classical signaling is primarily anti-inflammatory, whereas trans-signaling induces the pro-inflammatory effects of IL-6. The purpose of this study was to compare the effects of these two pathways on paracellular permeability and expression of genes involved in inter-endothelial junctions in human retinal endothelial cells (HRECs). IL-6 trans-signaling activation caused significant disruption to paracellular integrity, with increased paracellular permeability, and was associated with significant changes in gene expression related to adherens, tight, and gap junctions. IL-6 classical signaling did not alter paracellular resistance in HRECs and had no distinct effects on gene expression. In conclusion, IL-6 trans-signaling, but not classical signaling, is a major mediator of the increased paracellular permeability characteristic of inner BRB breakdown in diabetic retinopathy. This study also identified potential inter-endothelial junction genes involved in the IL-6 trans-signaling mediated regulation of paracellular permeability in HRECs.

scholarly journals RNA-Seq analysis reveals gene expression changes induced by IL-6 trans-signaling activation in retinal endothelial cells

Cytokine ◽  
2021 ◽  
Vol 139 ◽  
pp. 155375
Author(s):  
Rebekah Robinson ◽  
Daria Brown ◽  
Lara Churchwell ◽  
Tae-Jin Lee ◽  
Sai Karthik Kodeboyina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Rna Seq ◽  
Retinal Endothelial Cells ◽  
Signaling Activation

Distinct gene expression patterns in chronic lymphocytic leukemia defined by usage of specific VH genes

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 2090-2093 ◽  
Author(s):  
Dirk Kienle ◽  
Axel Benner ◽  
Alexander Kröber ◽  
Dirk Winkler ◽  
Daniel Mertens ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Lymphocytic Leukemia ◽  
Expression Patterns ◽  
Gene Expression Pattern ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Expression Of Genes ◽  
Vh Genes ◽  
Signaling Activation

The mutation status and usage of specific VH genes such as V3-21 and V1-69 are potentially independent pathogenic and prognostic factors in chronic lymphocytic leukemia (CLL). To investigate the role of antigenic stimulation, we analyzed the expression of genes involved in B-cell receptor (BCR) signaling/activation, cell cycle, and apoptosis control in CLL using these specific VH genes compared to VH mutated (VH-MUT) and VH unmutated (VH-UM) CLL not using these VH genes. V3-21 cases showed characteristic expression differences compared to VH-MUT (up: ZAP70 [or ZAP-70]; down: CCND2, P27) and VH-UM (down: PI3K, CCND2, P27, CDK4, BAX) involving several BCR-related genes. Similarly, there was a marked difference between VH unmutated cases using the V1-69 gene and VH-UM (up: FOS; down: BLNK, SYK, CDK4, TP53). Therefore, usage of specific VH genes appears to have a strong influence on the gene expression pattern pointing to antigen recognition and ongoing BCR stimulation as a pathogenic factor in these CLL subgroups.

scholarly journals Decursin Inhibits VEGF-Mediated Inner Blood—Retinal Barrier Breakdown by Suppression of VEGFR-2 Activation

2009 ◽  
Vol 29 (9) ◽  
pp. 1559-1567 ◽  
Author(s):  
Jin Hyoung Kim ◽  
Jeong Hun Kim ◽  
You Mie Lee ◽  
Eun-Mi Ahn ◽  
Kyu-Won Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Vision Loss ◽  
Retinal Vessels ◽  
Tight Junction Proteins ◽  
Blood Retinal Barrier ◽  
Retinal Endothelial Cells ◽  
Extracellular Signal ◽  
Brb Breakdown ◽  
Junction Proteins

The blood—retinal barrier (BRB) is essential for the normal structural and functional integrity of the retina, whose breakdown could cause the serious vision loss. Vascular endothelial growth factor (VEGF), as a permeable factor, induces alteration of tight junction proteins to result in BRB breakdown. Herein, we demonstrated that decursin inhibits VEGF-mediated inner BRB breakdown through suppression of VEGFR-2 signaling pathway. In retinal endothelial cells, decursin inhibited VEGF-mediated hyperpermeability. Decursin prevented VEGF-mediated loss of tight junction proteins including zonula occludens-1 (ZO-1), ZO-2, and occludin in retinal endothelial cells, which was also supported by restoration of tight junction proteins in intercellular junction. In addition, decursin significantly inhibited VEGF-mediated vascular leakage from retinal vessels, which was accompanied by prevention of loss of tight junction proteins in retinal vessels. Decursin significantly suppressed VEGF-induced VEGFR-2 phosphrylation that consequently led to inhibition of extracellular signal-regulated kinase (ERK) 1/2 activation. Moreover, decursin induced no cytotoxicity to retinal endothelial cells and no retinal toxicity under therapeutic concentrations. Therefore, our results suggest that decursin prevents VEGF-mediated BRB breakdown through blocking of loss of tight junction proteins, which might be regulated by suppression of VEGFR-2 activation. As a novel inhibitor to BRB breakdown, decursin could be applied to variable retinopathies with BRB breakdown.

scholarly journals Distinct downstream signaling and the roles of VEGF and PlGF in high glucose-mediated injuries of human retinal endothelial cells in culture

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wanzhen Jiao ◽  
Jia-Fu Ji ◽  
Wenwen Xu ◽  
Wenjuan Bu ◽  
Yuanjie Zheng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Growth Factor ◽  
High Glucose ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Blood Retinal Barrier ◽  
Western Blots ◽  
Retinal Endothelial Cells ◽  
Protein Levels

Abstract Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) plays a crucial role in breakdown of the blood-retinal barrier due to hyperpermeability in diabetic retinopathy (DR). However, the distinct signaling driven by VEGF and PlGF in the pathogenesis of DR remains unclear. In this study, we investigated VEGF- and PlGF- related signaling pathways and their roles in cultured human microvascular retinal endothelial cells (hRECs) under high glucose conditions (HG; 25 mM). Apoptotic cell death was evaluated, and FITC conjugated bovine serum albumin across monolayer hRECs served as an index of permeability. Western blots were used to assess the protein levels of VEGF and PlGF, as well as the phosphorylation of p38MAPK, STAT1 and Erk1/2. Knockdown of VEGF and PlGF was performed by using siRNA. Following HG treatment, increases of VEGF and PlGF as well as PKC activity were detected in hRECs. Increased phosphorylations of p38MAPKThr180/Thr182, STAT1Ser727, and Erk1/2Tyr202/Tyr185 as well as VEGFR1Tyr1213 and VEGFR2Tyr1175 were also detected in HG-treated hRECs. Inhibition of PKC activity by Go 6976 prevented HG-induced increases of phosphor-Erk1/2 and nitric oxide synthase (NOS1) expressions as well as hyperpermeability, whereas inhibition of p38MAPK pathway by SB203580 selectively suppressed activation of STAT1 and decreased apoptotic cell death under HG conditions. Moreover, VEGF knockdown predominantly inhibited activation of VEGFR2, and phosphorylation of p38MAPK and STAT1, as well as apoptotic cell death in HG-treated hRECs. Nevertheless, PlGF knockdown mainly suppressed phosphorylation of VEGFR1, PKC, and Erk1/2, as well as NOS1 expressions and hyperpermeability. Taken together, we provide evidence demonstrating that HG-induced elevation of PlGF is responsible for hyperpermeability mainly through increasing activation of PKC-Erk1/2-NOS axis via VEGFR1, while HG-induced elevation of VEGF is associated with induction of apoptotic cell death mainly through increasing activation of p38MAPK/STAT1 signaling via VEGFR2.

scholarly journals Transcription Factor PLAGL1 Is Associated with Angiogenic Gene Expression in the Placenta

2020 ◽  
Vol 21 (21) ◽  
pp. 8317
Author(s):  
Rebekah R. Starks ◽  
Rabab Abu Alhasan ◽  
Haninder Kaur ◽  
Kathleen A. Pennington ◽  
Laura C. Schulz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Transcription Factor ◽  
Gene Networks ◽  
Critical Role ◽  
Placental Development ◽  
Human Trophoblast ◽  
Mouse Placenta ◽  
Expression Of Genes ◽  
Sirna Knockdown

During pregnancy, the placenta is important for transporting nutrients and waste between the maternal and fetal blood supply, secreting hormones, and serving as a protective barrier. To better understand placental development, we must understand how placental gene expression is regulated. We used RNA-seq data and ChIP-seq data for the enhancer associated mark, H3k27ac, to study gene regulation in the mouse placenta at embryonic day (e) 9.5, when the placenta is developing a complex network of blood vessels. We identified several upregulated transcription factors with enriched binding sites in e9.5-specific enhancers. The most enriched transcription factor, PLAGL1 had a predicted motif in 233 regions that were significantly associated with vasculature development and response to insulin stimulus genes. We then performed several experiments using mouse placenta and a human trophoblast cell line to understand the role of PLAGL1 in placental development. In the mouse placenta, Plagl1 is expressed in endothelial cells of the labyrinth layer and is differentially expressed in placentas from mice with gestational diabetes compared to placentas from control mice in a sex-specific manner. In human trophoblast cells, siRNA knockdown significantly decreased expression of genes associated with placental vasculature development terms. In a tube assay, decreased PLAGL1 expression led to reduced cord formation. These results suggest that Plagl1 regulates overlapping gene networks in placental trophoblast and endothelial cells, and may play a critical role in placental development in normal and complicated pregnancies.

A novel co-culture model of the blood-retinal barrier based on primary retinal endothelial cells, pericytes and astrocytes

2012 ◽  
Vol 96 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Joanna Wisniewska-Kruk ◽  
Kees A. Hoeben ◽  
Ilse M.C. Vogels ◽  
Pieter J. Gaillard ◽  
Cornelis J.F. Van Noorden ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Retinal Barrier ◽  
Retinal Endothelial Cells ◽  
Culture Model

scholarly journals Differences in Activation of Intracellular Signalling in Primary Human Retinal Endothelial Cells Between Isoforms of VEGFA-165

2019 ◽  
Author(s):  
Wendelin Dailey ◽  
Roberto Shunemann ◽  
Fang Yang ◽  
Megan Moore ◽  
Austen Knapp ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Dose Response ◽  
Target Gene ◽  
Intracellular Signalling ◽  
Signalling Pathways ◽  
Response Curves ◽  
Retinal Endothelial Cells ◽  
Intracellular Signalling Pathways ◽  
Maximum Activation

ABSTRACTPurposeThere are reports that a b-isoform of Vascular Endothelial Growth Factor-A-165 (VEGFA165b) is predominant in normal human vitreous, switching to the a-isoform (VEGFA165a) in the vitreous of some diseased eyes. While these isoforms appear to have a different ability to activate the VEGF-Receptor-2 (VEGFR2) in various endothelial cells, the nature of their ability to activate intracellular signalling pathways is not fully characterized, especially in retinal endothelial cells. We determined their activation potential for two key intracellular signalling pathways (MAPK, AKT) over complete dose-response curves and compared potential effects on the expression of several VEGFA165 target genes in primary human retinal microvascular endothelial cells (HRMECs).MethodsTo determine full dose-response curves for the activation of MAPK (ERK1/2), AKT and VEGFR2, direct in-cell western assays were developed using primary Human Retinal Microvascular Endothelial Cells (HRMECs). Potential differences in dose-response effects on gene expression markers related to endothelial cell / leukocyte adhesion (ICAM1, VCAM1 and SELE) and tight-junctions (CLDN5 and OCLN) were tested by quantitative-PCR.ResultsActivation dose-response analysis revealed much stronger activation of MAPK, AKT and VEGFR2 by the a-isoform at lower doses. MAPK activation in primary HRMECs displayed a sigmoidal dose-response to a range of VEGFA165a concentrations spanning 10-250 pM, which shifted higher into the 100-5,000 pM range with VEGFA165b. Similar maximum activation of MAPK was achieved by both isoforms at high concentration. Maximum activation of AKT by VEGFA165b was only half of the maximum activation from VEGFA165a. At a lower intermediate dose, where VEGFA165a activated intracellular signalling stronger than VEGFA165b, the changes to VEGFA target gene expression was generally greater with VEGFA165a.ConclusionsIn primary HRMECs, VEGFA165a could maximally activate MAPK and AKT at lower concentrations where VEGFA165b had relatively little effect. The timing for maximal activation of MAPK was similar for both isoforms, which is different than reprorted for non-retinal endothelial cells. While VEGFA165a and VEGFA165b are limited to the sequence of their six C-terminal six amino acids, this results in a large difference in their ablility to activate at least two key intracellular signalling pathways and potentially VEGF target gene expression in primary human retinal endothelial cells.

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