scholarly journals Par-3 mediates the inhibition of LIM kinase 2 to regulate cofilin phosphorylation and tight junction assembly

2006 ◽  
Vol 172 (5) ◽  
pp. 671-678 ◽  
Author(s):  
Xinyu Chen ◽  
Ian G. Macara
Keyword(s):  
Tight Junction ◽  
Cell Polarization ◽  
Actin Dynamics ◽  
Lim Kinase ◽  
Kinase C ◽  
Cofilin Phosphorylation ◽  
Upstream Kinase ◽  
Novel Target ◽  
Axon Specification

The polarity protein Par-3 plays critical roles in axon specification and the establishment of epithelial apico-basal polarity. Par-3 associates with Par-6 and atypical protein kinase C and is required for the proper assembly of tight junctions, but the molecular basis for its functions is poorly understood. We now report that depletion of Par-3 elevates the phosphorylated pool of cofilin, a key regulator of actin dynamics. Expression of a nonphosphorylatable mutant of cofilin partially rescues tight junction assembly in cells lacking Par-3, as does the depletion of LIM kinase 2 (LIMK2), an upstream kinase for cofilin. Par-3 binds to LIMK2 but not to the related kinase LIMK1. Par-3 inhibits LIMK2 activity in vitro, and overexpressed Par-3 suppresses cofilin phosphorylation that is induced by lysophosphatidic acid. Our findings identify LIMK2 as a novel target of Par-3 and uncover a molecular mechanism by which Par-3 could regulate actin dynamics during cell polarization.

scholarly journals Downregulation of miRNA-451a Promotes the Differentiation of CD4+ T Cells towards Th2 Cells by Upregulating ETS1 in Childhood Asthma

2020 ◽  
pp. 1-11
Author(s):  
Tianyue  Wang ◽  
Qianlan Zhou ◽  
Yunxiao Shang
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
Cd4 T Cells ◽  
Peripheral Blood Lymphocytes ◽  
Cell Polarization ◽  
Luciferase Assay ◽  
Th2 Cells ◽  
Th2 Cell ◽  
Novel Target

Children exposed to common aeroallergens may develop asthma that progresses into adulthood. Inflammation regulated by T helper 2 (Th2) cells, a specific subpopulation of CD4+ T lymphocytes, is involved in asthmatic injury. Herein, our microarray data indicated that microRNA-451a-5p (miRNA-451a) expression decreased by 4.6-fold and ETS proto-oncogene 1 (ETS1) increased by 2.2-fold in the peripheral blood lymphocytes isolated from asthmatic children (<i>n</i> = 4) as compared to control individuals (<i>n</i> = 4). The negative correlation between miRNA-451a and ETS1 was further validated in 40 CD4+ T cell samples (10 healthy vs. 30 asthmatic samples). In vitro, naïve CD4+ T cells isolated from control individuals were cultured under Th2 cell polarizing condition. miRNA-451a expression decreased while ETS1 increased in CD4+ T cells in the setting of Th2 cell polarization. Moreover, miRNA-451a knockdown enhanced Th2 cell polarization – cells positive for both GATA3 (GATA binding protein 3, a Th2-transcription factor) and CD4 increased, and the generation of Th2 cell cytokines, interleukin (IL)5 and IL13, increased. In contrast, miRNA-451a overexpression inhibited Th2 cell differentiation. Interestingly, dual-Luciferase assay proved ETS1 as a novel target of miRNA-451a. Moreover, enforced expression of ETS1 partially restored miRNA-451a-induced inhibition of IL5 and IL13, and increased the GATA3+CD4+ cell population. Collectively, our work demonstrates that downregulation of miRNA-451a upregulates ETS1 expression in CD4+ T cells, which may contribute to Th2 cell differentiation in pediatric asthma.

scholarly journals TRA2A-induced upregulation of LINC00662 regulates blood-brain barrier permeability by affecting ELK4 mRNA stability in Alzheimer's microenvironment

2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Brain Barrier ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Novel Target ◽  
Related Proteins

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.

scholarly journals Spatio-temporal expression pattern and role of the tight junction protein MarvelD3 in pancreas development and function

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charlotte Heymans ◽  
Ophélie Delcorte ◽  
Catherine Spourquet ◽  
Mylah Villacorte-Tabelin ◽  
Sébastien Dupasquier ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tight Junction ◽  
Expression Pattern ◽  
Pancreatic Tissue ◽  
Cell Polarization ◽  
Tight Junction Protein ◽  
Jnk Pathway ◽  
Genetic Ablation ◽  
Junction Protein

AbstractTight junction complexes are involved in the establishment and maintenance of cell polarity and the regulation of signalling pathways, controlling biological processes such as cell differentiation and cell proliferation. MarvelD3 is a tight junction protein expressed in adult epithelial and endothelial cells. In Xenopus laevis, MarvelD3 morphants present differentiation defects of several ectodermal derivatives. In vitro experiments further revealed that MarvelD3 couples tight junctions to the MEKK1-JNK pathway to regulate cell behaviour and survival. In this work, we found that MarvelD3 is expressed from early developmental stages in the exocrine and endocrine compartments of the pancreas, as well as in endothelial cells of this organ. We thoroughly characterized MarvelD3 expression pattern in developing pancreas and evaluated its function by genetic ablation. Surprisingly, inactivation of MarvelD3 in mice did not alter development and differentiation of the pancreatic tissue. Moreover, tight junction formation and organization, cell polarization, and activity of the JNK-pathway were not impacted by the deletion of MarvelD3.

scholarly journals Twinfilin1 controls lamellipodial protrusive activity and actin turnover during vertebrate gastrulation

2020 ◽  
Author(s):  
Caitlin C. Devitt ◽  
Chanjae Lee ◽  
Rachael M. Cox ◽  
Ophelia Papoulas ◽  
José Alvarado ◽  
...  
Keyword(s):  
Animal Cell ◽  
Dynamic Control ◽  
Deep Understanding ◽  
Early Embryo ◽  
Cell Polarization ◽  
Actin Dynamics ◽  
Convergent Extension ◽  
Cell Movements ◽  
Actin Turnover

AbstractThe dynamic control of the actin cytoskeleton is a key aspect of essentially all animal cell movements. Experiments in single migrating cells and in vitro systems have provided an exceptionally deep understanding of actin dynamics. However, we still know relatively little of how these systems are tuned in cell-type specific ways, for example in the context of collective cell movements that sculpt the early embryo. Here, we provide an analysis of the actin severing and depolymerization machinery during vertebrate gastrulation, with a focus on Twinfilin1. We confirm previous results on the role of Twf1 in lamellipodia and extend those findings by linking Twf1, actin turnover, and cell polarization required for convergent extension during vertebrate gastrulation.

scholarly journals TRA2A-induced upregulation of LINC00662 regulates blood-brain barrier permeability by affecting ELK4 mRNA stability in Alzheimer's microenvironment

2019 ◽  
Author(s):  
Qianshuo Liu ◽  
Lu Zhu ◽  
Xiaobai Liu ◽  
Jian Zheng ◽  
Yunhui Liu ◽  
...  
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Brain Barrier ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Novel Target ◽  
Related Proteins

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.

scholarly journals Essential role of CIB1 in regulating PAK1 activation and cell migration

2005 ◽  
Vol 170 (3) ◽  
pp. 465-476 ◽  
Author(s):  
Tina M. Leisner ◽  
Mingjuan Liu ◽  
Zahara M. Jaffer ◽  
Jonathan Chernoff ◽  
Leslie V. Parise
Keyword(s):  
Cell Migration ◽  
Specific Interaction ◽  
Dependent Manner ◽  
Lim Kinase ◽  
Calcium Dependent ◽  
Cellular Processes ◽  
Cofilin Phosphorylation ◽  
Pak1 Activation

p21-activated kinases (PAKs) regulate many cellular processes, including cytoskeletal rearrangement and cell migration. In this study, we report a direct and specific interaction of PAK1 with a 22-kD Ca2+-binding protein, CIB1, which results in PAK1 activation both in vitro and in vivo. CIB1 binds to PAK1 within discrete regions surrounding the inhibitory switch domain in a calcium-dependent manner, providing a potential mechanism of CIB1-induced PAK1 activation. CIB1 overexpression significantly decreases cell migration on fibronectin as a result of a PAK1-and LIM kinase–dependent increase in cofilin phosphorylation. Conversely, the RNA interference–mediated depletion of CIB1 increases cell migration and reduces normal adhesion-induced PAK1 activation and cofilin phosphorylation. Together, these results demonstrate that endogenous CIB1 is required for regulated adhesion-induced PAK1 activation and preferentially induces a PAK1-dependent pathway that can negatively regulate cell migration. These results point to CIB1 as a key regulator of PAK1 activation and signaling.

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