The RNA-binding protein quaking maintains endothelial barrier function and affects VE-cadherin and β-catenin protein expression

Endothelial barrier function plays a major role in the onset of atherosclerosis. This barrier is maintained largely by adherens junctions. Remarkably, little is known about their regulation at the post–transcriptional level. We found that the RNA-binding protein Quaking (QKI), known for its function in embryonic blood vessel formation, is highly expressed in quiescent endothelial cells (EC) in vivo. In vitro, EC displayed increased levels of QKI when cultured under laminar, atheroprotective flow. Using KLF2 overexpression and a human QKI promoter reporter gene, we found that KLF2 mediates this increase in QKI expression. Subsequently, we aimed to investigate the role of QKI in EC vascular integrity. Interestingly, the mRNA of VE-cadherin, the prime adhesion protein in EC adherens junctions, contains a conserved QKI-binding site. We identified that the targeted reduction of QKI results in a reduction of VE-cadherin expression and organization at the cell periphery. These studies revealed a direct role for QKI in regulating VE-cadherin mRNA biology, as RNA-immunoprecipitation and luciferase-reporter assays revealed that QKI can directly bind to the VE-cadherin mRNA and induce transcript translation (4 fold ± 0.4; p<0.01), respectively. This effect was perturbed when the QKI-binding site was mutated. These results suggest that QKI acts to enhance barrier function. Overexpression of QKI markedly increased the capacity to form a high resistance endothelial monolayer (1.3 fold ± 0.96), while silencing of QKI markedly impaired EC barrier function (0.65 fold ± 0.13; p<0.05). To validate in vivo, we measured Bradykinin-induced vascular leakage in QKI viable mice (QKIv), which express decreased levels of the QKI protein. Indeed, QKIv mice displayed a 20% (p<0.05) increase in extravascular accumulation of Evans blue-labeled albumin compared to WT littermates. In conclusion, we show that QKI functions as a critical regulator of VE-cadherin, and the modulation of QKI expression affects endothelial monolayer integrity. These studies provide novel insight into the importance of post-transcriptional regulation on endothelial barrier function, and may have wide ranging implications for the preservation of vascular integrity in disease.

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Abstract 296: The RNA-Binding Protein Quaking Maintains Endothelial Barrier Function Through Targeting Vascular Endothelial Cadherin mRNA

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.33.suppl_1.a296 ◽

2013 ◽

Vol 33 (suppl_1) ◽

Author(s):

Janine M van Gils ◽

Ruben G de Bruin ◽

Iris Schmidt ◽

Eric P van der Veer ◽

Marko K Roeten ◽

...

Keyword(s):

High Resistance ◽

Barrier Function ◽

Rna Binding ◽

Adherens Junctions ◽

Rna Binding Protein ◽

Endothelial Barrier ◽

Vascular Endothelial ◽

Endothelial Monolayer ◽

Endothelial Barrier Function ◽

Vascular Endothelial Cadherin

Endothelial cells (ECs) form a vital barrier between the blood and the artery wall, and play a major role in the onset of atherosclerosis. Endothelial monolayer integrity is determined largely by EC-cell interactions, where vascular endothelial cadherin (VE-cadherin) is the central adhesive component at these endothelial adherens junctions. While many of the receptors and signaling proteins involved in regulating these adherens junctions have been identified, surprisingly little is known regarding their regulation at the post[[Unable to Display Character: ‐]]transcriptional level. The RNA-binding protein Qauking (QKI), originally known for its function in the nervous system, has been demonstrated to be essential for blood vessel formation. We find that QKI is highly expressed in quiescent ECs, in vitro and in vivo. In contrast, human umbilical vein ECs displayed reduced levels of QKI in response to the inflammatory stimuli TNF-α as well as in cells lacking cell-cell contacts, suggesting that QKI may act to enhance barrier function. To test this, we specifically abrogated QKI expression in ECs and measured their capacity to form a high-resistance monolayer with Electrical Cell-substrate Impedance Sensing. Silencing of QKI did not affect EC adhesion or spreading, but markedly affected the capacity to form a high resistance endothelial monolayer. Consistent with these data, and the fact that VE-cadherin mRNA contains a putative QKI-response element, the targeted reduction in QKI was accompanied by a significant reduction in VE-cadherin expression at cell junctions. Importantly, we identified a direct role for QKI in regulating VE-cadherin mRNA biology, as RNA immunoprecipitation and luciferase-reporter assays revealed that QKI can directly bind to the VE-cadherin mRNA and regulate transcript stability, respectively. In conclusion, we show that the modulation of QKI expression levels affects endothelial monolayer integrity by functioning as a critical regulator of the VE-cadherin mRNA. These studies provide novel insight into a role for post-transcriptional regulation in the maintenance of endothelial barrier function, and may have wide ranging implications for the preservation of vascular integrity in disease.

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291 LncRNA Spry4-it1 Modulates Tight Junction Expression and Epithelial Barrier Function Through Interaction With the RNA-Binding Protein HuR

Gastroenterology ◽

10.1016/s0016-5085(14)60250-x ◽

2014 ◽

Vol 146 (5) ◽

pp. S-69

Author(s):

Lan Xiao ◽

Rao N. Jaladanki ◽

Myriam Gorospe ◽

Jian-Ying Wang

Keyword(s):

Tight Junction ◽

Barrier Function ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Epithelial Barrier ◽

Epithelial Barrier Function

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Cold-induced RNA-binding protein (CIRBP) regulates the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) during heat stress-induced testicular injury

Reproduction Fertility and Development ◽

10.1071/rd20253 ◽

2020 ◽

Vol 32 (18) ◽

pp. 1357

Author(s):

Chengcheng Xu ◽

Dandan Ke ◽

Liping Zou ◽

Nianyu Li ◽

Yingying Wang ◽

...

Keyword(s):

Gene Expression ◽

Heat Stress ◽

Protein Expression ◽

Rna Binding ◽

Cell Model ◽

Binding Protein ◽

Rna Binding Protein ◽

Protein Levels ◽

Extracellular Signal ◽

Testicular Injury

In this study, the ability of cold-induced RNA-binding protein (CIRBP) to regulate the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) in the mouse testis and mouse primary spermatocytes (GC-2spd cell line) before and after heat stress was examined to explore the molecular mechanism by which CIRBP decreases testicular injury. A mouse testicular hyperthermia model, a mouse primary spermatocyte hyperthermia model and a low CIRBP gene-expression cell model were constructed and their relevant parameters were analysed. The mRNA and protein levels of CIRBP and Sam68 were significantly decreased in the 3-h and 12-h testicular heat-stress groups, extracellular signal-regulated kinase 1/2 (ERK1/2) protein expression was not significantly affected but phospho-ERK1/2 protein levels were significantly decreased. GC-2spd cellular heat-stress results showed that the mRNA and protein concentrations of CIRBP and Sam68 were reduced 48h after heat stress. In the low CIRBP gene-expression cell model, CIRBP protein expression was significantly decreased. Sam68 mRNA expression was significantly decreased only at the maximum transfection concentration of 50nM and Sam68 protein expression was not significantly affected. These findings suggest that CIRBP may regulate the expression of Sam68 at the transcriptional level and the expression of phospho-ERK1/2 protein, both of which protect against heat-stress-induced testicular injury in mice.

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Lipopolysaccharide (LPS)-binding protein and soluble CD14 function as accessory molecules for LPS-induced changes in endothelial barrier function, in vitro.

Journal of Clinical Investigation ◽

10.1172/jci117022 ◽

1994 ◽

Vol 93 (2) ◽

pp. 692-702 ◽

Cited By ~ 75

Author(s):

S E Goldblum ◽

T W Brann ◽

X Ding ◽

J Pugin ◽

P S Tobias

Keyword(s):

Barrier Function ◽

Binding Protein ◽

Endothelial Barrier ◽

Endothelial Barrier Function ◽

Soluble Cd14 ◽

Accessory Molecules ◽

Induced Changes ◽

Lps Binding

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Caspase-mediated Cleavage of RNA-binding Protein HuR Regulates c-Myc Protein Expression after Hypoxic Stress

Journal of Biological Chemistry ◽

10.1074/jbc.m111.255927 ◽

2011 ◽

Vol 286 (37) ◽

pp. 32333-32343 ◽

Cited By ~ 38

Author(s):

Sudha Talwar ◽

Junfei Jin ◽

Brittany Carroll ◽

Angen Liu ◽

Marion Boyd Gillespie ◽

...

Keyword(s):

Protein Expression ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Hypoxic Stress

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Tu1741 RNA-Binding Protein HuR Enhances Translation of E-Cadherin and Modulates Epithelial Barrier Function

Gastroenterology ◽

10.1016/s0016-5085(13)63104-2 ◽

2013 ◽

Vol 144 (5) ◽

pp. S-834-S-835

Author(s):

Tingxi Yu ◽

Bei-Lin Gu ◽

Wei Cai

Keyword(s):

Barrier Function ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Epithelial Barrier ◽

Epithelial Barrier Function ◽

E Cadherin

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Posttranscriptional Regulation of HLA-A Protein Expression by Alternative Polyadenylation Signals Involving the RNA-Binding Protein Syncrip

The Journal of Immunology ◽

10.4049/jimmunol.1700697 ◽

2017 ◽

Vol 199 (11) ◽

pp. 3892-3899 ◽

Cited By ~ 16

Author(s):

Smita Kulkarni ◽

Veron Ramsuran ◽

Marijana Rucevic ◽

Sukhvinder Singh ◽

Alexandra Lied ◽

...

Keyword(s):

Protein Expression ◽

Posttranscriptional Regulation ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Alternative Polyadenylation ◽

Polyadenylation Signals

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H19Long Noncoding RNA Regulates Intestinal Epithelial Barrier Function via MicroRNA 675 by Interacting with RNA-Binding Protein HuR

Molecular and Cellular Biology ◽

10.1128/mcb.01030-15 ◽

2016 ◽

Vol 36 (9) ◽

pp. 1332-1341 ◽

Cited By ~ 52

Author(s):

Tongtong Zou ◽

Suraj K. Jaladanki ◽

Lan Liu ◽

Lan Xiao ◽

Hee Kyoung Chung ◽

...

Keyword(s):

Barrier Function ◽

Noncoding Rna ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Epithelial Barrier ◽

Intestinal Epithelial ◽

Intestinal Epithelial Barrier ◽

Epithelial Barrier Function ◽

E Cadherin

The disruption of the intestinal epithelial barrier function occurs commonly in various pathologies, but the exact mechanisms responsible are unclear. TheH19long noncoding RNA (lncRNA) regulates the expression of different genes and has been implicated in human genetic disorders and cancer. Here, we report thatH19plays an important role in controlling the intestinal epithelial barrier function by serving as a precursor for microRNA 675 (miR-675).H19overexpression increased the cellular abundance of miR-675, which in turn destabilized and repressed the translation of mRNAs encoding tight junction protein ZO-1 and adherens junction E-cadherin, resulting in the dysfunction of the epithelial barrier. Increasing the level of the RNA-binding protein HuR in cells overexpressingH19prevented the stimulation of miR-675 processing fromH19, promoted ZO-1 and E-cadherin expression, and restored the epithelial barrier function to a nearly normal level. In contrast, the targeted deletion of HuR in intestinal epithelial cells enhanced miR-675 production in the mucosa and delayed the recovery of the gut barrier function after exposure to mesenteric ischemia/reperfusion. These results indicate thatH19interacts with HuR and regulates the intestinal epithelial barrier function via theH19-encoded miR-675 by altering ZO-1 and E-cadherin expression posttranscriptionally.

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