scholarly journals Single-Cell RNA Sequencing Reveals Heterogeneity of Vascular Cells in Early Stage Murine Abdominal Aortic Aneurysm—Brief Report

2021 ◽  
Vol 41 (3) ◽  
pp. 1158-1166
Author(s):  
Huan Yang ◽  
Ting Zhou ◽  
Amelia Stranz ◽  
Elise DeRoo ◽  
Bo Liu

Objective: Abdominal aortic aneurysm (AAA) is a life-threatening vascular disease characterized by smooth muscle cell depletion, ECM (extracellular matrix) degradation, and infiltration of immune cells. The cellular and molecular profiles that govern the heterogeneity of the AAA aorta are yet to be elucidated. Approach and Results: We performed single-cell RNA sequencing on mouse AAA tissues. AAA was induced in C57BL/6J mice by perivascular application of CaCl 2 . Unbiased clustering identified 12 distinct populations of 8 cell types. Percentages of each population and gene expression were compared between sham and AAA tissue. Furthermore, we characterized the transcriptional profiles and potential functional features of populations in smooth muscle cells, fibroblasts, and macrophages and revealed the unique regulons in each cell type. Conclusions: Together, these data provide high-resolution insight into the complexity and heterogeneity of mouse AAA and indicate that populations within major cell types such as smooth muscle cells, fibroblasts, and macrophages may contribute differently to AAA pathogenesis. Graphic Abstract: A graphic abstract is available for this article.

2021 ◽  
Author(s):  
Yingzheng Weng ◽  
Jiangjie Lou ◽  
Yizong Bao ◽  
Changhong Cai ◽  
Kefu Zhu ◽  
...  

Abstract Aim: The mechanism of abdominal aortic aneurysm (AAA) has not been fully elucidated. In this study, we aimed to map the cellular heterogeneity, molecular alteration, and functional transformation of angiotensin (Ang) II-induced AAA in mice based on single-cell RNA sequencing (sc-RNA seq) technology.Method: Single-cell RNA sequencing was performed on suprarenal abdominal aorta from male APOE-/- C57BL/6 mice of Ang II-induced AAA and shame models. Immunohistochemistry was used to determine the pathophysiological characteristics of AAA, and sc-RNA seq was used to determine the heterogeneity and phenotypic transformation of all cell types. A single-cell trajectory was performed to predict the differentiation of fibroblasts. Finally ligand–receptor analysis was used to evaluate intercellular communication between fibroblasts and smooth muscle cells.Results: More than 27,000 cells were isolated and 25 clusters representing 8 types of cells were identified, including fibroblasts, macrophages, endothelial cells, smooth muscle cells, T lymphocytes, B lymphocytes, granulocytes, and natural killer cells. During AAA progression, the function and phenotype of different type cells altered separately. The pro-inflammatory function of inflammatory cells was enhanced. The proliferation phenotype degreased while pro-inflammatory, regeneration and damage-related phenotypes increased in endothelial cells. Smooth muscle cells also transformed from contractile to secretory phenotype. The alterations of fibroblasts were the most conspicuous according sub-group clustering analysis. Single-cell trajectory revealed the critical reprogramming genes of fibroblasts mainly enriched in regulation of immune system. Finally, the ligand–receptor analysis confirmed that increases in secondary collagen synthesis led by fibroblasts were one of the most prominent characteristics of Ang II-induced AAA.Conclusion: Our study revealed the cellular heterogeneity of Ang II-induced AAA. Fibroblasts may play a central role in Ang II-induced AAA progression according multiple biological functions including immune regulation and extracellular matrix metabolic balance. Our study may provide us with a different perspective on the etiology and pathogenesis of AAA.


2010 ◽  
Vol 67 (12) ◽  
pp. 959-964 ◽  
Author(s):  
Irena Tanaskovic ◽  
Aleksandra Mladenovic-Mihailovic ◽  
Slavica Usaj-Knezevic ◽  
Vesna Stankovic ◽  
Aleksandar Aleksic ◽  
...  

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.


2021 ◽  
Author(s):  
Joscha Mulorz ◽  
Mahdis Shayan ◽  
Caroline Hu ◽  
Cynthia Alcazar ◽  
Alex H.P Chan ◽  
...  

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...


2020 ◽  
Vol 40 (6) ◽  
pp. 1559-1573
Author(s):  
Taro Hiromi ◽  
Utako Yokoyama ◽  
Daisuke Kurotaki ◽  
Al Mamun ◽  
Ryo Ishiwata ◽  
...  

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.


2019 ◽  
Vol 70 (5) ◽  
pp. e142-e143 ◽  
Author(s):  
Michele Silvestro ◽  
Tarik Hadi ◽  
Neal S. Cayne ◽  
Thomas S. Maldonado ◽  
Bruce E. Gelb ◽  
...  

PLoS ONE ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. e35312 ◽  
Author(s):  
Giuseppe Cafueri ◽  
Federica Parodi ◽  
Angela Pistorio ◽  
Maria Bertolotto ◽  
Francesco Ventura ◽  
...  

Author(s):  
Haocheng Lu ◽  
Wa Du ◽  
Lu Ren ◽  
Milton H. Hamblin ◽  
Richard C. Becker ◽  
...  

Abstract Aortic aneurysm, including thoracic aortic aneurysm and abdominal aortic aneurysm, is the second most prevalent aortic disease following atherosclerosis, representing the ninth‐leading cause of death globally. Open surgery and endovascular procedures are the major treatments for aortic aneurysm. Typically, thoracic aortic aneurysm has a more robust genetic background than abdominal aortic aneurysm. Abdominal aortic aneurysm shares many features with thoracic aortic aneurysm, including loss of vascular smooth muscle cells (VSMCs), extracellular matrix degradation and inflammation. Although there are limitations to perfectly recapitulating all features of human aortic aneurysm, experimental models provide valuable tools to understand the molecular mechanisms and test novel therapies before human clinical trials. Among the cell types involved in aortic aneurysm development, VSMC dysfunction correlates with loss of aortic wall structural integrity. Here, we discuss the role of VSMCs in aortic aneurysm development. The loss of VSMCs, VSMC phenotypic switching, secretion of inflammatory cytokines, increased matrix metalloproteinase activity, elevated reactive oxygen species, defective autophagy, and increased senescence contribute to aortic aneurysm development. Further studies on aortic aneurysm pathogenesis and elucidation of the underlying signaling pathways are necessary to identify more novel targets for treating this prevalent and clinical impactful disease.


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