scholarly journals Lin11-Isl1-Mec3 Domain Proteins as Mechanotransducers in Endothelial and Vascular Smooth Muscle Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Sporkova ◽  
Subhajit Ghosh ◽  
Jaafar Al-Hasani ◽  
Markus Hecker

Arterial hypertension is the leading risk factor for cardiovascular morbidity and mortality worldwide. However, little is known about the cellular mechanisms underlying it. In small arteries and arterioles, a chronic increase in blood pressure raises wall tension and hence stretches, namely, the medial vascular smooth muscle cells (VSMC) but also endothelial cell (EC) to cell contacts. Initially compensated by an increase in vascular tone, the continuous biomechanical strain causes a prominent change in gene expression in both cell types, frequently driving an arterial inward remodeling process that ultimately results in a reduction in lumen diameter, stiffening of the vessel wall, and fixation of blood pressure, namely, diastolic blood pressure, at the elevated level. Sensing and propagation of this supraphysiological stretch into the nucleus of VSMC and EC therefore seems to be a crucial step in the initiation and advancement of hypertension-induced arterial remodeling. Focal adhesions (FA) represent an important interface between the extracellular matrix and Lin11-Isl1-Mec3 (LIM) domain-containing proteins, which can translocate from the FA into the nucleus where they affect gene expression. The varying biomechanical cues to which vascular cells are exposed can thus be rapidly and specifically propagated to the nucleus. Zyxin was the first protein described with such mechanotransducing properties. It comprises 3 C-terminal LIM domains, a leucine-rich nuclear export signal, and N-terminal features that support its association with the actin cytoskeleton. In the cytoplasm, zyxin promotes actin assembly and organization as well as cell motility. In EC, zyxin acts as a transcription factor, whereas in VSMC, it has a less direct effect on mechanosensitive gene expression. In terms of homology and structural features, lipoma preferred partner is the nearest relative of zyxin among the LIM domain proteins. It is almost exclusively expressed by smooth muscle cells in the adult, resides like zyxin at FA but seems to affect mechanosensitive gene expression indirectly, possibly via altering cortical actin dynamics. Here, we highlight what is currently known about the role of these LIM domain proteins in mechanosensing and transduction in vascular cells.

Circulation ◽  
2000 ◽  
Vol 102 (15) ◽  
pp. 1828-1833 ◽  
Author(s):  
Georg Nickenig ◽  
Kerstin Strehlow ◽  
Sven Wassmann ◽  
Anselm T. Bäumer ◽  
Katja Albory ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1748
Author(s):  
Eda Demirel ◽  
Caroline Arnold ◽  
Jaspal Garg ◽  
Marius Andreas Jäger ◽  
Carsten Sticht ◽  
...  

The regulator of G-protein signaling 5 (RGS5) acts as an inhibitor of Gαq/11 and Gαi/o activity in vascular smooth muscle cells (VSMCs), which regulate arterial tone and blood pressure. While RGS5 has been described as a crucial determinant regulating the VSMC responses during various vascular remodeling processes, its regulatory features in resting VSMCs and its impact on their phenotype are still under debate and were subject of this study. While Rgs5 shows a variable expression in mouse arteries, neither global nor SMC-specific genetic ablation of Rgs5 affected the baseline blood pressure yet elevated the phosphorylation level of the MAP kinase ERK1/2. Comparable results were obtained with 3D cultured resting VSMCs. In contrast, overexpression of RGS5 in 2D-cultured proliferating VSMCs promoted their resting state as evidenced by microarray-based expression profiling and attenuated the activity of Akt- and MAP kinase-related signaling cascades. Moreover, RGS5 overexpression attenuated ERK1/2 phosphorylation, VSMC proliferation, and migration, which was mimicked by selectively inhibiting Gαi/o but not Gαq/11 activity. Collectively, the heterogeneous expression of Rgs5 suggests arterial blood vessel type-specific functions in mouse VSMCs. This comprises inhibition of acute agonist-induced Gαq/11/calcium release as well as the support of a resting VSMC phenotype with low ERK1/2 activity by suppressing the activity of Gαi/o.


2015 ◽  
Vol 36 (6) ◽  
pp. 2466-2479 ◽  
Author(s):  
XiaoLe Xu ◽  
Mengzi He ◽  
Tingting Liu ◽  
Yi Zeng ◽  
Wei Zhang

Background/Aims: salusin-ß is considered to be a potential pro-atherosclerotic factor. Regulation and function of vascular smooth muscle cells (VSMCs) are important in the progression of atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARγ) exerts a vascular protective role beyond its metabolic effects. Salusin-ß has direct effects on VSMCs. The aim of the present study was to assess the effect of salusin-ß on PPARγ gene expression in primary cultured rat VSMCs. Methods: Western blotting analysis, real-time PCR and transient transfection approach were used to determine expression of target proteins. Specific protein knockdown was performed with siRNA transfection. Cell proliferation was determined by 5-bromo-2'-deoxyuridine incorporation. The levels of inflammation indicators interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) were determined using enzyme-linked immunosorbent assay. Results: Salusin-ß negatively regulated PPARγ gene expression at protein, mRNA and gene promoter level in VSMCs. The inhibitory effect of salusin-ß on PPARγ gene expression contributed to salusin-ß-induced VSMCs proliferation and inflammation in vitro. IγBa-NF-γB activation, but not NF-γB p50 or p65, mediated the salusin-ß-induced inhibition of PPARγ gene expression. Salusin-ß induced nuclear translocation of histone deacetylase 3 (HDAC3). HDAC3 siRNA prevented salusin-ß-induced PPARγ reduction. Nuclear translocation of HDAC3 in response to salusin-ß was significantly reversed by an IγBa inhibitor BAY 11-7085. Furthermore, IγBa-HDAC3 complex was present in the cytosol of VSMCs but interrupted after salusin-ß treatment. Conclusion: IγBa-HDAC3 pathway may contribute to salusin-ß-induced inhibition of PPARγ gene expression in VSMCs.


1998 ◽  
Vol 274 (2) ◽  
pp. C472-C480 ◽  
Author(s):  
Shinji Naito ◽  
Shunichi Shimizu ◽  
Shigeto Maeda ◽  
Jianwei Wang ◽  
Richard Paul ◽  
...  

Ets-1 is a transcription factor that activates expression of matrix-degrading proteinases such as collagenase and stromelysin. To study the control of ets-1 gene expression in rat vascular smooth muscle cells (VSMC), cells were exposed to factors known to regulate VSMC migration and proliferation. Platelet-derived growth factor-BB (PDGF-BB), endothelin-1 (ET-1), and phorbol 12-myristate 13-acetate (PMA) induced a dose-dependent expression of ets-1 mRNA. These effects were abrogated by inhibition of protein kinase C (PKC) by H-7 or chronic PMA treatment. Ets-1 mRNA was superinduced by PDGF-BB and ET-1 in the presence of cycloheximide. The chelation of intracellular Ca2+ by 1,2-bis(2-aminophenoxy)ethane- N, N, N′, N′-tetraacetic acid-acetoxymethyl ester and the depletion of endoplasmic reticulum intracellular Ca2+concentration ([Ca2+]i) by thapsigargin inhibited PDGF-BB- and ET-1-induced ets-1 mRNA, whereas ethylene glycol-bis(β-aminoethyl ether)- N, N, N′, N′-tetraacetic acid had no effect. However, [Ca2+]irelease alone was not sufficient to increase ets-1 mRNA. Forskolin blocked ET-1-, PDGF-BB-, and PMA-induced ets-1 mRNA, as well as inositol phosphate formation, consistent with an effect through impairment of PKC activation. Inhibitors of ets-1 gene expression, such as H-7 and herbimycin A, inhibited the ET-1 induction of collagenase I mRNA. We propose that ets-1 may be an important element in the orchestration of matrix proteinase expression and of vascular remodeling after arterial injury.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoqiang Qi ◽  
Yujing Zhang ◽  
Jing Li ◽  
Dongxia Hou ◽  
Yang Xiang

We assessed the role of PGC-1α (PPARγ coactivator-1 alpha) in glucose-induced proliferation, migration, and inflammatory gene expression of vascular smooth muscle cells (VSMCs). We carried out phagocytosis studies to assess the role of PGC-1α in transdifferentiation of VSMCs by flow cytometry. We found that high glucose stimulated proliferation, migration and inflammatory gene expression of VSMCs, but overexpression of PGC-1α attenuated the effects of glucose. In addition, overexpression of PGC-1α decreased mRNA and protein level of VSMCs-related genes, and induced macrophage-related gene expression, as well as phagocytosis of VSMCs. Therefore, PGC-1α inhibited glucose-induced proliferation, migration and inflammatory gene expression of VSMCs, which are key features in the pathology of atherosclerosis. More importantly, PGC-1α transdifferentiated VSMCs to a macrophage-like state. Such transdifferentiation possibly increased the portion of VSMCs-derived foam cells in the plaque and favored plaque stability.


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