scholarly journals Pseudogene ACTBP2 increases blood–brain barrier permeability by promoting KHDRBS2 transcription through recruitment of KMT2D/WDR5 in Aβ1–42 microenvironment

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Qianshuo Liu ◽  
Xiaobai Liu ◽  
Defeng Zhao ◽  
Xuelei Ruan ◽  
Rui Su ◽  
...  

AbstractThe blood–brain barrier (BBB) has a vital role in maintaining the homeostasis of the central nervous system (CNS). Changes in the structure and function of BBB can accelerate Alzheimer’s disease (AD) development. β-Amyloid (Aβ) deposition is the major pathological event of AD. We elucidated the function and possible molecular mechanisms of the effect of pseudogene ACTBP2 on the permeability of BBB in Aβ1–42 microenvironment. BBB model treated with Aβ1–42 for 48 h were used to simulate Aβ-mediated BBB dysfunction in AD. We proved that pseudogene ACTBP2, RNA-binding protein KHDRBS2, and transcription factor HEY2 are highly expressed in ECs that were obtained in a BBB model in vitro in Aβ1–42 microenvironment. In Aβ1–42-incubated ECs, ACTBP2 recruits methyltransferases KMT2D and WDR5, binds to KHDRBS2 promoter, and promotes KHDRBS2 transcription. The interaction of KHDRBS2 with the 3′UTR of HEY2 mRNA increases the stability of HEY2 and promotes its expression. HEY2 increases BBB permeability in Aβ1–42 microenvironment by transcriptionally inhibiting the expression of ZO-1, occludin, and claudin-5. We confirmed that knocking down of Khdrbs2 or Hey2 increased the expression levels of ZO-1, occludin, and claudin-5 in APP/PS1 mice brain microvessels. ACTBP2/KHDRBS2/HEY2 axis has a crucial role in the regulation of BBB permeability in Aβ1–42 microenvironment, which may provide a novel target for the therapy of AD.

2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  

Abstract The blood-brain barrier (BBB) plays a pivotal role in maintenance and regulation of the neural microenvironment. The occurrence of BBB disruption is the pathological change of early Alzheimer’s disease (AD). RNA-binding proteins and long non-coding RNAs are involved in the regulation of BBB permeability. Our study was performed to demonstrate TRA2A/LINC00662/ELK4 axis in regulating BBB permeability in AD microenvironment. In Aβ1-42-incubated microvascular endothelial cells (ECs) of BBB model in vitro, TRA2A and LINC00662 were enriched. TRA2A increased the stability of LINC00662 by binding with it. The knockdown of either TRA2A or LINC00662 decreased the BBB permeability via upregulating the expressions of tight junction-related proteins. ELK4 was lower expressed in BBB model in vitro in AD microenvironment. LINC00662 mediated the degradation of ELK4 mRNA by SMD pathway. The downregulated ELK4 increased the permeability of BTB by increasing the tight junction-related proteins expressions. TRA2A/LINC00662/ELK4 axis plays a crucial role in the regulation of BBB permeability in AD microenvironment, which may provide a novel target for the therapy of AD.


2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  

Abstract The blood-brain barrier (BBB) plays a pivotal role in maintenance and regulation of the neural microenvironment. The occurrence of BBB disruption is the pathological change of early Alzheimer’s disease (AD). RNA-binding proteins and long non-coding RNAs are involved in the regulation of BBB permeability. Our study was performed to demonstrate TRA2A/LINC00662/ELK4 axis in regulating BBB permeability in AD microenvironment. In Aβ1-42-incubated microvascular endothelial cells (ECs) of BBB model in vitro, TRA2A and LINC00662 were enriched. TRA2A increased the stability of LINC00662 by binding with it. The knockdown of either TRA2A or LINC00662 decreased the BBB permeability via upregulating the expressions of tight junction-related proteins. ELK4 was lower expressed in BBB model in vitro in AD microenvironment. LINC00662 mediated the degradation of ELK4 mRNA by SMD pathway. The downregulated ELK4 increased the permeability of BTB by increasing the tight junction-related proteins expressions. TRA2A/LINC00662/ELK4 axis plays a crucial role in the regulation of BBB permeability in AD microenvironment, which may provide a novel target for the therapy of AD.


2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  

AbstractThe blood-brain barrier (BBB) has an important significance in maintenance and regulation of the neural microenvironment. The occurrence of BBB disruption is the pathological change of early Alzheimer’s disease (AD). RNA-binding proteins and long non-coding RNAs are closely related to the regulation of BBB permeability. Our study was performed to demonstrate TRA2A/LINC00662/ELK4 axis that regulates BBB permeability in AD microenvironment. In Aβ1-42-incubated microvascular endothelial cells (ECs) of BBB model in vitro, TRA2A and LINC00662 were enriched. TRA2A increased the stability of LINC00662 by binding with it. The knockdown of either TRA2A or LINC00662 decreased the BBB permeability via upregulating the levels of tight junction-related proteins. ELK4 was downregulated in BBB model in vitro in AD microenvironment. LINC00662 mediated the degradation of ELK4 mRNA by SMD pathway. The downregulated ELK4 increased the permeability of BTB by inducing the tight junction-related proteins. TRA2A/LINC00662/ELK4 axis is important in the regulation of BBB permeability in AD microenvironment, which would be a new molecular target for AD treatment.


2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Sun ◽  
Jusheng Wu ◽  
Fuzhou Hua ◽  
Yong Chen ◽  
Fenfang Zhan ◽  
...  

Sleep deprivation occurs frequently in older adults, which can result in delirium and cognitive impairment. CD44 is a key molecular in blood-brain barrier (BBB) regulation. However, whether CD44 participates in the role of sleep deprivation in cognitive impairment remains unclear. In this study, the effect of sleep deprivation on cognitive ability, tissue inflammation, BBB permeability, and astrocyte activity were evaluated in vivo. The differentially expressed genes (DEGs) were identified by RNA sequencing. A CD44 overexpression in the BBB model was performed in vitro to assess the effect and mechanisms of CD44. Sleep deprivation impaired the learning and memory ability and increased the levels of inflammatory cytokines, along with increased BBB permeability and activated astrocytes in hippocampus tissue. RNA sequencing of the hippocampus tissue revealed that 329 genes were upregulated in sleep deprivation-induced mice compared to control mice, and 147 genes were downregulated. GO and pathways showed that DEGs were mainly involved in BBB permeability and astrocyte activation, including nervous system development, neuron development, and brain development, and neuroactive ligand-receptor interaction. Moreover, the PCR analysis revealed that CD44 was dramatically increased in mice with sleep deprivation induction. The overexpression of CD44 in astrocytes promoted BBB permeability in vitro and induced the expression of the downstream gene NANOG. Our results indicate that sleep deprivation upregulated CD44 expression in hippocampus tissue, and increased BBB permeability, resulting in cognitive impairment.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Yilv Wan ◽  
Min Song ◽  
Xun Xie ◽  
Zhen Chen ◽  
Ziyun Gao ◽  
...  

Background. In patients with subarachnoid hemorrhage (SAH), the damage of the blood-brain barrier (BBB) can be life-threatening. Mesenchymal stem cells are widely used in clinical research due to their pleiotropic properties. This study is aimed at exploring the effect of BMSCs regulating astrocytes on the BBB after SAH. Methods. The SAH model was established by perforating the blood vessels. BMSCs were transfected with TSG-6 inhibitor plasmid and cocultured with astrocytes. Intravenous transplantation of BMSCs was utilized to treat SAH rats. We performed ELISA, neurological scoring, Evans blue staining, NO measurement, immunofluorescence, BBB permeability, Western blot, HE staining, Nissl staining, and immunohistochemistry to evaluate the effect of BMSCs on astrocytes and BBB. Results. SAH rats showed BBB injury, increased BBB permeability, and brain histological damage. BMSCs will secrete TSG-6 after being activated by TNF-α. Under the influence of TSG-6, the NF-κB and MAPK signaling pathways of astrocytes were inhibited. The expression of iNOS was reduced, while occludin, claudin 3, and ZO-1 expression was increased. The production of harmful substances NO and ONOO- decreased. The level of inflammatory factors decreased. The apoptosis of astrocytes was weakened. TSG-6 secreted by BMSCs can relieve inflammation caused by SAH injury. The increase in BBB permeability of SAH rats was further reduced and the risk of rebleeding was reduced. Conclusion. BMSCs can regulate the activation of astrocytes through secreting TSG-6 in vivo and in vitro to protect BBB.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252595
Author(s):  
Cécile Khou ◽  
Marco Aurelio Díaz-Salinas ◽  
Anaelle da Costa ◽  
Christophe Préhaud ◽  
Patricia Jeannin ◽  
...  

Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in South East Asia. It has been suggested that, as a consequence of the inflammatory process during JEV infection, there is disruption of the blood-brain barrier (BBB) tight junctions that in turn allows the virus access to the central nervous system (CNS). However, what happens at early times of JEV contact with the BBB is poorly understood. In the present work, we evaluated the ability of both a virulent and a vaccine strain of JEV (JEV RP9 and SA14-14-2, respectively) to cross an in vitro human BBB model. Using this system, we demonstrated that both JEV RP9 and SA14-14-2 are able to cross the BBB without disrupting it at early times post viral addition. Furthermore, we find that almost 10 times more RP9 infectious particles than SA14-14 cross the model BBB, indicating this BBB model discriminates between the virulent RP9 and the vaccine SA14-14-2 strains of JEV. Beyond contributing to the understanding of early events in JEV neuroinvasion, we demonstrate this in vitro BBB model can be used as a system to study the viral determinants of JEV neuroinvasiveness and the molecular mechanisms by which this flavivirus crosses the BBB during early times of neuroinvasion.


Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 843
Author(s):  
Bo Kyung Lee ◽  
Soo-Wang Hyun ◽  
Yi-Sook Jung

Yuzu and its main component, hesperidin (HSP), have several health benefits owing to their anti-inflammatory and antioxidant properties. We examined the effects of yuzu and HSP on blood–brain barrier (BBB) dysfunction during ischemia/hypoxia in an in vivo animal model and an in vitro BBB endothelial cell model, and also investigated the underlying mechanisms. In an in vitro BBB endothelial cell model, BBB permeability was determined by measurement of Evans blue extravasation in vivo and in vitro. The expression of tight junction proteins, such as claudin-5 and zonula occludens-1 (ZO-1), was detected by immunochemistry and western blotting, and the reactive oxygen species (ROS) level was measured by 2′7′-dichlorofluorescein diacetate intensity. Yuzu and HSP significantly ameliorated the increase in BBB permeability and the disruption of claudin-5 and ZO-1 in both in vivo and in vitro models. In bEnd.3 cells, yuzu and HSP were shown to inhibit the disruption of claudin-5 and ZO-1 during hypoxia, and the protective effects of yuzu and HSP on claudin-5 degradation seemed to be mediated by Forkhead box O 3a (FoxO3a) and matrix metalloproteinase (MMP)-3/9. In addition, well-known antioxidants, trolox and N-acetyl cysteine, significantly attenuated the BBB permeability increase, disruption of claudin-5 and ZO-1, and FoxO3a activation during hypoxia, suggesting that ROS are important mediators of BBB dysfunction during hypoxia. Collectively, these results indicate that yuzu and HSP protect the BBB against dysfunction via maintaining integrity of claudin-5 and ZO-1, and these effects of yuzu and HSP appear to be a facet of their antioxidant properties. Our findings may contribute to therapeutic strategies for BBB-associated neurodegenerative diseases.


2019 ◽  
Vol 20 (14) ◽  
pp. 1163-1171 ◽  
Author(s):  
Deeksha Saxena ◽  
Anju Sharma ◽  
Mohammed H. Siddiqui ◽  
Rajnish Kumar

Blood Brain Barrier (BBB) is the collection of vessels of blood with special properties of permeability that allow a limited range of drug and compounds to pass through it. The BBB plays a vital role in maintaining balance between intracellular and extracellular environment for brain. Brain Capillary Endothelial Cells (BECs) act as vehicle for transport and the transport mechanisms across BBB involve active and passive diffusion of compounds. Efficient prediction models of BBB permeability can be vital at the preliminary stages of drug development. There have been persistent efforts in identifying the prediction of BBB permeability of compounds employing multiple machine learning methods in an attempt to minimize the attrition rate of drug candidates taking up preclinical and clinical trials. However, there is an urgent need to review the progress of such machine learning derived prediction models in the prediction of BBB permeability. In the current article, we have analyzed the recently developed prediction model for BBB permeability using machine learning.


2022 ◽  
Author(s):  
Andrew V Stachulski ◽  
Tobias B-A Knausenberger ◽  
Sita N Shah ◽  
Lesley Hoyles ◽  
Simon McArthur

Purpose: The sequential activity of gut microbial and host processes can exert a powerful modulatory influence on dietary components, as exemplified by the metabolism of the amino acids tyrosine and phenylalanine to p-cresol by gut microbes, and then to p-cresol glucuronide (pCG) by host enzymes. Although such glucuronide conjugates are classically thought to be biologically inert, there is accumulating evidence that this may not always be the case. We investigated the activity of pCG, studying its interactions with the cerebral vasculature and the brain in vitro and in vivo. Methods: Male C57Bl/6J mice were used to assess blood-brain barrier (BBB) permeability and whole brain transcriptomic changes in response to pCG treatment. Effects were then further explored using the human cerebromicrovascular endothelial cell line hCMEC/D3, assessing paracellular permeability, transendothelial electrical resistance and barrier protein expression. Results: Mice exposed to pCG showed reduced BBB permeability and significant changes in whole brain transcriptome expression. Surprisingly, treatment of hCMEC/D3 cells with pCG had no notable effects until co-administered with bacterial lipopolysaccharide, at which point it was able to prevent the permeabilising effects of endotoxin. Further analysis suggested that pCG acts as an antagonist at the principal lipopolysaccharide receptor TLR4. Conclusion: The amino acid phase II metabolic product pCG is biologically active at the BBB, highlighting the complexity of gut microbe to host communication and the gut-brain axis.


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