scholarly journals LncRNA SENCR suppresses abdominal aortic aneurysm formation by inhibiting smooth muscle cells apoptosis and extracellular matrix degradation

2020 ◽  
Author(s):  
Zhou Cai ◽  
Jianhua Huang ◽  
Junxiao Yang ◽  
Baihong Pan ◽  
Wei Wang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cells ◽  
Cell Apoptosis ◽  
Ang Ii ◽  
Matrix Degradation ◽  
Extracellular Matrix Degradation ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) is a progressive chronic dilatation of the abdominal aorta without effective medical treatment. This study aims to clarify the potential of long non-coding RNA SENCR as a treatment target in AAA. Angiotensin II (Ang-II) was used to establish AAA mouse model as well as a cell model based on the mouse aortic vascular smooth muscle cells (VSMCs). Reverse transcription quantitative PCR and western blot were performed to measure the expression of SENCR and proteins, respectively. Apoptotic rate in VSMCs was determined using Annexin V-FITC/PI double staining, and cell apoptosis in aortic tissues was determined by TUNEL staining. Hematoxylin and eosin and Elastica van Gieson staining were used for histological analysis of aortic tissues. SENCR was downregulated in AAA tissues and Ang-II-stimulated VSMCs. Overexpression of SENCR inhibited Ang-II-induced VSMC apoptosis, while inhibition of SENCR facilitated VSMC apoptosis. Moreover, overexpression of SENCR suppressed matrix metalloproteinase (MMP)-2 and MMP-9 expression and promoted tissue inhibitor of metalloproteinases 1 (TIMP-1) expression in Ang-II-induced VSMCs, while inhibition of SENCR expression led to the opposite results. In vivo, overexpressed SENCR improved the pathological change in aortic tissues and the damage in arterial wall elastic fibres induced by Ang-II, as well as it suppressed Ang-II-induced cell apoptosis and extracellular matrix degradation in aortic tissues. Overall, overexpression of SENCR inhibited AAA formation via suppressing VSMC apoptosis and extracellular matrix degradation. We provided a reliable evidence for SENCR acting as a potential target for AAA treatment.

scholarly journals BAF60a Deficiency in Vascular Smooth Muscle Cells Prevents Abdominal Aortic Aneurysm by Reducing Inflammation and Extracellular Matrix Degradation

2020 ◽  
Vol 40 (10) ◽  
pp. 2494-2507
Author(s):  
Ziyi Chang ◽  
Guizhen Zhao ◽  
Yang Zhao ◽  
Haocheng Lu ◽  
Wenhao Xiong ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Matrix Degradation ◽  
Extracellular Matrix Degradation ◽  
Abdominal Aortic

Objective: Currently, there are no approved drugs for abdominal aortic aneurysm (AAA) treatment, likely due to limited understanding of the primary molecular mechanisms underlying AAA development and progression. BAF60a—a unique subunit of the SWI/SNF (switch/sucrose nonfermentable) chromatin remodeling complex—is a novel regulator of metabolic homeostasis, yet little is known about its function in the vasculature and pathogenesis of AAA. In this study, we sought to investigate the role and underlying mechanisms of vascular smooth muscle cell (VSMC)–specific BAF60a in AAA formation. Approach and Results: BAF60a is upregulated in human and experimental murine AAA lesions. In vivo studies revealed that VSMC-specific knockout of BAF60a protected mice from both Ang II (angiotensin II)–induced and elastase-induced AAA formation with significant suppression of vascular inflammation, monocyte infiltration, and elastin fragmentation. Through RNA sequencing and pathway analysis, we found that the expression of inflammatory response genes in cultured human aortic smooth muscle cells was significantly downregulated by small interfering RNA–mediated BAF60a knockdown while upregulated upon adenovirus-mediated BAF60a overexpression. BAF60a regulates VSMC inflammation by recruiting BRG1 (Brahma-related gene-1)—a catalytic subunit of the SWI/SNF complex—to the promoter region of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) target genes. Furthermore, loss of BAF60a in VSMCs prevented the upregulation of the proteolytic enzyme cysteine protease CTSS (cathepsin S), thus ameliorating ECM (extracellular matrix) degradation within the vascular wall in AAA. Conclusions: Our study demonstrated that BAF60a is required to recruit the SWI/SNF complex to facilitate the epigenetic regulation of VSMC inflammation, which may serve as a potential therapeutic target in preventing and treating AAA.

scholarly journals Excessive EP4 Signaling in Smooth Muscle Cells Induces Abdominal Aortic Aneurysm by Amplifying Inflammation

2020 ◽  
Vol 40 (6) ◽  
pp. 1559-1573
Author(s):  
Taro Hiromi ◽  
Utako Yokoyama ◽  
Daisuke Kurotaki ◽  
Al Mamun ◽  
Ryo Ishiwata ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Macrophage Infiltration ◽  
Prostaglandin E ◽  
Ang Ii ◽  
Inflammatory Monocyte ◽  
Abdominal Aortic

Objective: Excessive prostaglandin E 2 production is a hallmark of abdominal aortic aneurysm (AAA). Enhanced expression of prostaglandin E 2 receptor EP4 (prostaglandin E receptor 4) in vascular smooth muscle cells (VSMCs) has been demonstrated in human AAAs. Although moderate expression of EP4 contributes to vascular homeostasis, the roles of excessive EP4 in vascular pathology remain uncertain. We aimed to investigate whether EP4 overexpression in VSMCs exacerbates AAAs. Approach and Results: We constructed mice with EP4 overexpressed selectively in VSMCs under an SM22α promoter (EP4-Tg). Most EP4-Tg mice died within 2 weeks of Ang II (angiotensin II) infusion due to AAA, while nontransgenic mice given Ang II displayed no overt phenotype. EP4-Tg developed much larger AAAs than nontransgenic mice after periaortic CaCl 2 application. In contrast, EP4 fl/+ ;SM22-Cre;ApoE −/ − and EP4 fl/+ ;SM22-Cre mice, which are EP4 heterozygous knockout in VSMCs, rarely exhibited AAA after Ang II or CaCl 2 treatment, respectively. In Ang II–infused EP4-Tg aorta, Ly6C hi inflammatory monocyte/macrophage infiltration and MMP-9 (matrix metalloprotease-9) activation were enhanced. An unbiased analysis revealed that EP4 stimulation positively regulated the genes binding cytokine receptors in VSMCs, in which IL (interleukin)-6 was the most strongly upregulated. In VSMCs of EP4-Tg and human AAAs, EP4 stimulation caused marked IL-6 production via TAK1 (transforming growth factor-β–activated kinase 1), NF-κB (nuclear factor-kappa B), JNK (c-Jun N-terminal kinase), and p38. Inhibition of IL-6 prevented Ang II–induced AAA formation in EP4-Tg. In addition, EP4 stimulation decreased elastin/collagen cross-linking protein LOX (lysyl oxidase) in both human and mouse VSMCs. Conclusions: Dysregulated EP4 overexpression in VSMCs promotes inflammatory monocyte/macrophage infiltration and attenuates elastin/collagen fiber formation, leading to AAA exacerbation.

scholarly journals Inducible Depletion of Calpain-2 Mitigates Abdominal Aortic Aneurysm in Mice

2021 ◽  
Author(s):  
Latha Muniappan ◽  
Michihiro Okuyama ◽  
Aida Javidan ◽  
Devi Thiagarajan ◽  
Weihua Jiang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Structural Integrity ◽  
Mesenchymal Cell ◽  
Ang Ii ◽  
Structural Protein ◽  
Abdominal Aortic ◽  
Calpain 2

Objective: Cytoskeletal structural proteins maintain cell structural integrity by bridging extracellular matrix with contractile filaments. During abdominal aortic aneurysm (AAA) development, (1) aortic medial degeneration is associated with loss of smooth muscle cell integrity and (2) fibrogenic mesenchymal cells mediate extracellular matrix remodeling. Calpains cleave cytoskeletal proteins that maintain cell structural integrity. Pharmacological inhibition of calpains exert beneficial effects on Ang II (angiotensin II)–induced AAAs in LDLR −/− (low-density receptor deficient) mice. Here, we evaluated the functional contribution of fibrogenic mesenchymal cells-derived calpain-2 on (1) cytoskeletal structural protein and extracellular matrix alterations and (2) AAA progression. Approach and Results: Calpain-2 protein and cytoskeletal protein (filamin and talin) fragmentation are significantly elevated in human and Ang II–induced AAAs in mice. To examine the relative contribution of calpain-2 in AAA development, calpain-2 floxed mice in an LDLr −/− background were bred to mice with a tamoxifen-inducible form of Cre under control of either the ubiquitous promoter, chicken β-actin, or fibrogenic mesenchymal cell-specific promoter, Col1α2. Ubiquitous or fibrogenic mesenchymal cell-specific depletion of calpain-2 in mice suppressed Ang II–induced AAAs, filamin/talin fragmentation, while promoting extracellular matrix protein, collagen in the aortas. Calpain-2 silencing in aortic smooth muscle cells or fibroblasts reduced Ang II–induced filamin fragmentation. In addition, silencing of filamin in aortic SMCs significantly reduced collagen protein. Furthermore, calpain-2 deficiency suppressed rupture of established Ang II–induced AAAs in mice. Conclusions: Our studies implicate that calpain-2 deficiency prevents (1) Ang II–induced cytoskeletal structural protein fragmentation and AAA development and (2) stabilize and suppress rupture of established AAAs in mice.

scholarly journals Knockdown of long noncoding RNA GAS5 reduces vascular smooth muscle cell apoptosis by inactivating EZH2-mediated RIG-I signaling pathway in abdominal aortic aneurysm

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Tianming Le ◽  
Xin He ◽  
Jianhua Huang ◽  
Shuai Liu ◽  
Yang Bai ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Rna Binding ◽  
Ectopic Expression ◽  
Tunel Staining ◽  
Ang Ii ◽  
Abdominal Aortic

Abstract Background Abdominal aortic aneurysm (AAA), an irreversible cardiovascular disease prevalent in the artery, causes the increase of the aneurysm diameter over time, and is a fatal phenomenon inducing sidewall rupture. Long noncoding RNAs (lncRNAs) serve as promising biomarkers for AAA. In the present study, we sought to define the role of lncRNA growth-arrest-specific transcript 5 (GAS5) in growth of smooth muscle cells (SMC) and progression of AAA. Methods Initially, we established angiotensin II (Ang II)-induced AAA mouse models and Ang II-treated vascular SMC model. RT-qPCR and Western blot analysis were adopted to determine expression of GAS5 and zeste homolog 2 (EZH2). After ectopic expression and depletion experiments in Ang II-treated mice and vascular SMCs, cell apoptosis was detected in SMCs using flow cytometry and in mice using TUNEL staining. The binding of GAS5 and EZH2 was evaluated using RNA binding protein immunoprecipitation (RIP) and Co-IP assays. Results Increased GAS5 and RIG-I but decreased EZH2 were found in aortic tissues of AAA mice. EZH2 overexpression inhibited AAA formation and suppressed SMC apoptosis. Functionally, EZH2 blocked the RIG-I signaling pathway and consequently inhibited SMC apoptosis. GAS5 regulated EZH2 transcription in a negative manner in SMCs. Knockdown of GAS5 attenuated SMC apoptosis, which was reversed by EZH2 inhibition or RIG-I overexpression. Conclusions The current study demonstrated that GAS5 induced SMC apoptosis and subsequent AAA onset by activating EZH2-mediated RIG-I signaling pathway, highlighting GAS5 as a novel biomarker for AAA.

scholarly journals Histochemical and immunohistochemical analysis of ruptured atherosclerotic abdominal aortic aneurysm wall

2010 ◽  
Vol 67 (12) ◽  
pp. 959-964 ◽  
Author(s):  
Irena Tanaskovic ◽  
Aleksandra Mladenovic-Mihailovic ◽  
Slavica Usaj-Knezevic ◽  
Vesna Stankovic ◽  
Aleksandar Aleksic ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cells ◽  
Periodic Acid ◽  
Muscle Cells ◽  
Foam Cells ◽  
Abdominal Aortic ◽  
S 100 ◽  
The Media

Background/Aim. The main complication of the atherosclerotic abdominal aortic aneurism (AAA) is her rupture that begins with lesion in intima and rupture. The purpose of this work was to determine immunocytochemical and morphofunctional characteristics of the cells in aortic wall in ruptured atherosclerotic abdominal aortic aneurysm. Method. During the course of this study, 20 samples of atherosclerotic AAA were analyzed, all of them obtained during authopsy. The samples were fixed in 4% formalin and embedded in paraffin. Sections of 5 ?m thickness were stained histochemically (of Heidenhain azan stain and Periodic acid Schiff - PAS stain) and immunocytochemically using a DAKO LSAB+/HRP technique to identify ?-smooth muscle actin (?-SMA), vimentin, myosin heavy chains (MHC), desmin, S-100 protein, CD45 and CD68 (DAKO specification). Results. The results of our study showed that ruptured atherosclerotic AAA is characterized by a complete absence of endothelial cells, the disruption of basal membrane and internal elastic lamina, as well as a presence of the remains of hypocellular complicated atherosclerotic lesion in intima. On the plaque margins, as well as in the media, smooth muscle cells (SMCs) are present, which express a ?-SMA and vimentin (but without MHC or desmin expression), as well as leukocyte infiltration, and a large number of foam cells. Some of the foam cells show a CD68-immunoreactivity, while the others show vimentin- and S-100 protein-immunoreactivity. Media is thinned out with a disorganized elastic lamellas, while adventitia is characterized by inflammatory inflitrate (infection). Conclusion. Rupture of aneurysm occurs from the primary intimal disruption, which spreads into thinned out media and adventitia. Rupture is caused by unstable atherom, hypocellularity, loss of contractile characteristics of smooth muscle cells in intima and media, neovascularization of the media, as well as by the activity of the macrophages in the lesion.

Peri-Adventitial Delivery of Smooth Muscle Cells in Porous Collagen Scaffolds for Treatment of Experimental Abdominal Aortic Aneurysm

2021 ◽  
Author(s):  
Joscha Mulorz ◽  
Mahdis Shayan ◽  
Caroline Hu ◽  
Cynthia Alcazar ◽  
Alex H.P Chan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Vessel Wall ◽  
Muscle Cells ◽  
Collagen Scaffolds ◽  
Abdominal Aortic ◽  
Direct Delivery

Abdominal aortic aneurysm (AAA) is associated with the loss of vascular smooth muscle cells (SMCs) within the vessel wall. Direct delivery of therapeutic cells is challenging due to impaired mechanical...

scholarly journals Genetic and Epigenetic Mechanisms Underlying Vascular Smooth Muscle Cell Phenotypic Modulation in Abdominal Aortic Aneurysm

2020 ◽  
Vol 21 (17) ◽  
pp. 6334
Author(s):  
Rijan Gurung ◽  
Andrew Mark Choong ◽  
Chin Cheng Woo ◽  
Roger Foo ◽  
Vitaly Sorokin
Keyword(s):  
Smooth Muscle ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Smooth Muscle Cells ◽  
Aortic Wall ◽  
Epigenetic Mechanisms ◽  
Phenotypic Modulation ◽  
Abdominal Aortic

Abdominal aortic aneurysm (AAA) refers to the localized dilatation of the infra-renal aorta, in which the diameter exceeds 3.0 cm. Loss of vascular smooth muscle cells, degradation of the extracellular matrix (ECM), vascular inflammation, and oxidative stress are hallmarks of AAA pathogenesis and contribute to the progressive thinning of the media and adventitia of the aortic wall. With increasing AAA diameter, and left untreated, aortic rupture ensues with high mortality. Collective evidence of recent genetic and epigenetic studies has shown that phenotypic modulation of smooth muscle cells (SMCs) towards dedifferentiation and proliferative state, which associate with the ECM remodeling of the vascular wall and accompanied with increased cell senescence and inflammation, is seen in in vitro and in vivo models of the disease. This review critically analyses existing publications on the genetic and epigenetic mechanisms implicated in the complex role of SMCs within the aortic wall in AAA formation and reflects the importance of SMCs plasticity in AAA formation. Although evidence from the wide variety of mouse models is convincing, how this knowledge is applied to human biology needs to be addressed urgently leveraging modern in vitro and in vivo experimental technology.

Sign in / Sign up

Export Citation Format

Share Document