Abstract 14092: Reduction of Atherosclerosis in Gucy1a3 Deficient Mice

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Maria Segura Puimedon ◽  
Evanthia Mergia ◽  
Jaafar Al-Hasani ◽  
Redouane Aherrahrou ◽  
Jennifer Freyer ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Association Studies ◽  
Muscle Cells ◽  
Independent Experiment ◽  
Standard Diet ◽  
Genome Wide Association Studies ◽  
Primary Mouse

Introduction: GUCY1A3 encodes the α1 subunit of the soluble guanylate cyclase (sGC) and has been associated with CAD/MI by genome-wide association studies (GWAS) and in a rare extended family with MI. The α1 and the β1 subunit form the heterodimeric sGC, the nitric oxide (NO) receptor. NO plays an important role in the human cardiovascular system. The aim of our study is to define the role of GUCY1A3 in atherosclerosis using a mouse atherogenic model. Methods: Gucy1a3 KO mice were backcrossed on an Ldlr KO atherogenic background. Four groups were used, i.e. C57BL/6 (WT), Gucy1a3 KO, Ldlr KO and Gucy1a3-Ldlr double KO. All groups were fed high fat diet (HFD) or standard diet (SD) starting at the age of 12-14w and for 20 weeks. Blood pressure was studied at the end of the experiment in the HFD. At the start and end of the diet, lipid metabolism parameters (TC, HDLC, LDLC and TG) were analyzed. Plaque lesion size and collagen and macrophages content were studied. As smooth muscle cells play a key role in atherosclerosis, primary mouse aortic smooth muscle cells (maSMC) were isolated from WT and Gucy1a3 KO animals and subjected to proliferation and migration assays. Results: Blood pressure was studied in HFD animals, showing, as expected, an increase of systolic and diastolic blood pressure in double KO animals when compared to Ldlr KO animals. Regarding lipid levels, no differences were found in the double KO to Ldlr KO comparison under HFD, but a reduction in total cholesterol was found in double KO under SD. For atherosclerosis, a significant reduction in plaque area at the aortic root of double KO when compared to the Ldlr KO animals was demonstrated in both SD and HFD. The reduction was further confirmed in an additional independent experiment under SD. Similarly, a significant reduction of plaque lesion was found in the whole aorta of double KO when compared to the Ldlr KO under HFD. Moreover, a reduction in collagen content was found in double KO mice under HFD when compared to Ldlr KO animals. The migration and proliferation assays show a significant reduction in both migration and proliferation of the Gucy1a3 KO maSMC compared to WT. Conclusions: Our results point to an atherogenic role of Gucy1a3 in mice probably induced via smooth muscle migration and proliferation defects.

scholarly journals Microanatomy of the Human Atherosclerotic Plaque by Single-Cell Transcriptomics

2020 ◽  
Vol 127 (11) ◽  
pp. 1437-1455 ◽  
Author(s):  
Marie A.C. Depuydt ◽  
Koen H.M. Prange ◽  
Lotte Slenders ◽  
Tiit Örd ◽  
Danny Elbersen ◽  
...  
Keyword(s):  
T Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Single Cell ◽  
Association Studies ◽  
Myeloid Cells ◽  
Muscle Cells ◽  
Atherosclerotic Plaques ◽  
Genome Wide Association Studies ◽  
Mesenchymal Transition

Rationale: Atherosclerotic lesions are known for their cellular heterogeneity, yet the molecular complexity within the cells of human plaques has not been fully assessed. Objective: Using single-cell transcriptomics and chromatin accessibility, we gained a better understanding of the pathophysiology underlying human atherosclerosis. Methods and Results: We performed single-cell RNA and single-cell ATAC sequencing on human carotid atherosclerotic plaques to define the cells at play and determine their transcriptomic and epigenomic characteristics. We identified 14 distinct cell populations including endothelial cells, smooth muscle cells, mast cells, B cells, myeloid cells, and T cells and identified multiple cellular activation states and suggested cellular interconversions. Within the endothelial cell population, we defined subsets with angiogenic capacity plus clear signs of endothelial to mesenchymal transition. CD4 + and CD8 + T cells showed activation-based subclasses, each with a gradual decline from a cytotoxic to a more quiescent phenotype. Myeloid cells included 2 populations of proinflammatory macrophages showing IL (interleukin) 1B or TNF (tumor necrosis factor) expression as well as a foam cell-like population expressing TREM2 (triggering receptor expressed on myeloid cells 2) and displaying a fibrosis-promoting phenotype. ATACseq data identified specific transcription factors associated with the myeloid subpopulation and T cell cytokine profiles underlying mutual activation between both cell types. Finally, cardiovascular disease susceptibility genes identified using public genome-wide association studies data were particularly enriched in lesional macrophages, endothelial, and smooth muscle cells. Conclusions: This study provides a transcriptome-based cellular landscape of human atherosclerotic plaques and highlights cellular plasticity and intercellular communication at the site of disease. This detailed definition of cell communities at play in atherosclerosis will facilitate cell-based mapping of novel interventional targets with direct functional relevance for the treatment of human disease.

scholarly journals Loss of Chloride Channel 6 (CLC-6) Affects Vascular Smooth Muscle Contractility and Arterial Stiffness via Alterations to Golgi Calcium Stores

Hypertension ◽  
2021 ◽  
Author(s):  
Christine A. Klemens ◽  
Evgeny G. Chulkov ◽  
Jing Wu ◽  
Md Abdul Hye Khan ◽  
Vladislav Levchenko ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Chloride Channel ◽  
Muscle Cells ◽  
Calcium Stores ◽  
Pressure Regulation

Genome-wide association studies have found a number of potential genes involved in blood pressure regulation; however, the functional role of many of these candidates has yet to be established. One such candidate gene is CLCN6 , which encodes the transmembrane protein, chloride channel 6 (ClC-6). Although the CLCN6 locus has been widely associated with human blood pressure regulation, the mechanistic role of ClC-6 in blood pressure homeostasis at the molecular, cellular, and physiological levels is completely unknown. In this study, we demonstrate that rats with a functional knockout of ClC-6 on the Dahl Salt-Sensitive rat background (SS- Clcn6 ) have lower diastolic but not systolic blood pressures. The effect of diastolic blood pressure attenuation was independent of dietary salt exposure in knockout animals. Moreover, SS- Clcn6 rats are protected from hypertension-induced cardiac hypertrophy and arterial stiffening; however, they have impaired vasodilation and dysregulated intracellular calcium handling. ClC-6 is highly expressed in vascular smooth muscle cells where it is targeted to the Golgi apparatus. Using bilayer electrophysiology, we provide evidence that recombinant human ClC-6 protein can function as a channel. Last, we demonstrate that loss of ClC-6 function reduces Golgi calcium stores, which may play a previously unidentified role in vascular contraction and relaxation signaling in vascular smooth muscle cells. Collectively, these data indicate that ClC-6 may modulate blood pressure by regulating Golgi calcium reserves, which in turn contribute to vascular smooth muscle function.

Abstract 574: A Role for TWIST1 as GWAS Risk Gene for Coronary Artery Disease

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Sylvia T Nurnberg ◽  
Stephanie Testa ◽  
Joebert Rosal ◽  
Susannah Elwyn ◽  
Wei Zhao ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Potential Role ◽  
Muscle Cells ◽  
Human Aorta ◽  
Serum Starvation ◽  
Genome Wide Association Studies ◽  
Expression Levels

Genome-wide association studies (GWAS) have identified rs2107595 as association SNP for both stroke and cardiovascular disease. This polymorphism is located proximal to the HDAC9 gene, with TWIST1 106kb downstream as the next closest gene in the recombination interval. Whilst studies in hyperlipidemic Hdac9 knockout mice have demonstrated a pro-atherogenic effect of Hdac9, recent evidence suggests an additionally role of TWIST1 in atherosclerosis. For one, rs2107595 genotypes associate with differences in TWIST1 but not HDAC9 expression levels in human aorta (GTEx consortium, n=197, p=0.00016), proposing a role of TWIST1 downstream the association locus specifically in vascular smooth muscle cells. RNA-seq data from in vitro cultured human coronary artery smooth muscle (HCASMCs) and endothelial cells (HCAECs) shows differential expression of TWIST1 in smooth muscle cells (n=19/20, q=3E-60). Furthermore, TWIST1 expression is selectively upregulated in HCASMCs upon serum starvation, and TWIST1 protein is detected in human lesions both near the tunica media and at the fibrous cap where it co-localizes with smooth muscle actin (ACTA2). The GWAS association SNP is predicted to change transcription factor binding affinity from the more general E2F to RBPJ - a well-known modulator of Notch signaling in smooth muscle cells (Transfac professional, 2014.4 data release). The variant is located within an enhancer region in mesenchymal stem cells (Broad GSE17312), fibroblasts (UCSF-UBC-USD GSE16368) as well as in HCASMCs. Current studies explore the tissue-specific activity of this regulatory element through in vivo lacZ reporter assays to investigate a potential role in mouse coronary arteries. Genome editing studies in immortalized HCASMCs are being employed to investigate the effect of SNP genotype on expression levels of both TWIST1 and HDAC9. Future experiments using an inducible, smooth muscle specific knockout of Twist1 will interrogate the potential role of Twist1 in atherosclerosis.

The role of WNT/b-catenin signaling in smooth muscle cells during lung development and repair

Pneumologie ◽  
2014 ◽  
Vol 68 (06) ◽  
Author(s):  
A Moiseenko ◽  
E El Agha ◽  
B MacKenzie ◽  
S De Langhe ◽  
S Bellusci
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Lung Development ◽  
Muscle Cells

scholarly journals RGS5 Attenuates Baseline Activity of ERK1/2 and Promotes Growth Arrest of Vascular Smooth Muscle Cells

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1748
Author(s):  
Eda Demirel ◽  
Caroline Arnold ◽  
Jaspal Garg ◽  
Marius Andreas Jäger ◽  
Carsten Sticht ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Genetic Ablation ◽  
Variable Expression ◽  
Arterial Blood

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.

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