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Cell Proliferation Feb 2022Blood blister-like aneurysms (BBAs) are extremely rare aneurysms. They are predisposed to preoperative rerupture with a high case-fatality rate. Here, we attempt to...
OBJECTIVE
Blood blister-like aneurysms (BBAs) are extremely rare aneurysms. They are predisposed to preoperative rerupture with a high case-fatality rate. Here, we attempt to interrogate the distinct clinicopathology and the histological basis underlying its clinical rerupture.
METHODS
Three middle meningeal arteries, 11 BBA (5 reruptured, 6 non-rerupture) and 19 saccular aneurysm samples were obtained for histopathological investigation. Three reruptured BBAs, 3 non-reruptured BBAs and 6 saccular (3 ruptured, 3 unruptured) aneurysms were obtained for quantitative flow cytometry analysis.
RESULTS
Compared with true saccular aneurysms, the BBA aneurysm wall lacks arterial stroma cells including CD31+ endothelial cells and α-SMA + smooth muscle cells. Only fibroblasts and adventitial collagen were observed in the BBA aneurysm wall. Meanwhile, BBAs were enriched with infiltrated inflammatory cells, especially polarized macrophages. Based on the rerupture status, those reruptured BBAs showed drastically reduced fibroblasts and adventitia collagen. Moreover, M2-polarized macrophages were observed dominant in BBAs and exhibit repairing cellular functions based on their interplays with arterial fibroblasts. Reduced M2 macrophages and arterial tissue repairing modulation may be responsible for the decreasing collagen synthesis and fibrosis repairment, which potentially dampens the aneurysm integrity and induces BBA aneurysm reruputre.
CONCLUSIONS
BBAs poses histopathological features of occult pseudoaneurysms or dissecting aneurysms. Reduced M2 macrophages and adventitia collagen may dampen the structural integrity of BBAs and induce preoperative rerupture.
Topics: Adventitia; Collagen; Endothelial Cells; Humans; Intracranial Aneurysm; Macrophages; Treatment Outcome
PubMed: 34970805
DOI: 10.1111/cpr.13175 -
Diabetes & Vascular Disease Research 2022Obesity is linked to increased arterial size, carotid intima-media thickness and arterial stiffness. The effects of obesity and body composition on muscular artery...
Obesity is linked to increased arterial size, carotid intima-media thickness and arterial stiffness. The effects of obesity and body composition on muscular artery intima-media and adventitia thickness has previously not been established. The aim of this study was to explore associations between carotid and muscular artery wall layer thickness with body composition and cardiovascular risk factors in early middle-aged women. This is a cross-sectional study including 199 women aged 40±4 years. Arterial lumen (LD), intima-media (IMT) and adventitia thickness (AT) were measured from carotid, brachial and radial arteries using ultra-high frequency ultrasound (22-71 MHz). Women with obesity had increased IMT in carotid (0.47 vs 0.45 mm), brachial (0.19 vs 0.17 mm) and radial arteries (0.16 vs 0.15 mm) and increased brachial AT (0.14 vs 0.13 mm). In multiple regression models all arterial LD (β-range 0.02-0.03 mm/kg/m), IMT (β-range 0.91-3.37 µm/kg/m), AT (β-range 0.73-1.38 µm/kg/m) were significantly associated with BMI. The IMT of all arteries were significantly associated with systolic blood pressure (β-range 0.36-0.85 µm/mmHg), attenuating the association between IMT and BMI (β-range 0.18-2.24 µm/kg/m). Obese early middle-aged women have increased arterial intima media thickness and brachial artery adventitia thickness compared to non-obese counterparts. The association between BMI and intima-media thickness is partly mediated through blood pressure levels.
Topics: Adventitia; Carotid Arteries; Carotid Intima-Media Thickness; Cross-Sectional Studies; Female; Humans; Middle Aged; Obesity; Risk Factors
PubMed: 35637577
DOI: 10.1177/14791641221094321 -
Current Opinion in Immunology Jun 2020Advances in microscopy, genetically modified mice, and single-cell RNA sequencing have begun to deconvolute the composition and function of tissue immune niches. Here we... (Review)
Review
Advances in microscopy, genetically modified mice, and single-cell RNA sequencing have begun to deconvolute the composition and function of tissue immune niches. Here we discuss the evidence that the adventitia, the outermost layer of larger blood vessels, is a conserved niche and tissue immune outpost for multiple immune cells, including group 2 innate lymphoid cells (ILC2) and subsets of tissue-resident memory T cells, macrophages, and dendritic cells. We also describe the unique non-immune composition at adventitial regions, including fibroblast-like stromal cell subsets, lymphatic and blood endothelial cells, and neurons, and review how immune-stromal crosstalk impacts regional tissue immunity, organ adaptation, and disease.
Topics: Adventitia; Animals; Endothelial Cells; Humans; Immunity, Innate; Lymphocytes; Mice; Stromal Cells
PubMed: 32339862
DOI: 10.1016/j.coi.2020.03.005 -
PloS One 2015Previous research on vascular calcification has mainly focused on the vascular intima and media. However, we show here that vascular calcification may also occur in the...
Previous research on vascular calcification has mainly focused on the vascular intima and media. However, we show here that vascular calcification may also occur in the adventitia. The purpose of this work is to help elucidate the pathogenic mechanisms underlying vascular calcification. The calcified lesions were examined by Von Kossa staining in ApoE-/- mice which were fed high fat diets (HFD) for 48 weeks and human subjects aged 60 years and older that had died of coronary heart disease, heart failure or acute renal failure. Explant cultured fibroblasts and smooth muscle cells (SMCs)were obtained from rat adventitia and media, respectively. After calcification induction, cells were collected for Alizarin Red S staining. Calcified lesions were observed in the aorta adventitia and coronary artery adventitia of ApoE-/-mice, as well as in the aorta adventitia of human subjects examined. Explant culture of fibroblasts, the primary cell type comprising the adventitia, was successfully induced for calcification after incubation with TGF-β1 (20 ng/ml) + mineralization media for 4 days, and the phenotype conversion vascular adventitia fibroblasts into myofibroblasts was identified. Culture of SMCs, which comprise only a small percentage of all cells in the adventitia, in calcifying medium for 14 days resulted in significant calcification.Vascular calcification can occur in the adventitia. Adventitia calcification may arise from the fibroblasts which were transformed into myofibroblasts or smooth muscle cells.
Topics: Adventitia; Aged; Aged, 80 and over; Animals; Aorta; Apolipoproteins E; Cells, Cultured; Coronary Vessels; Female; Fibroblasts; Humans; Male; Mice; Mice, Knockout; Middle Aged; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta1; Vascular Calcification
PubMed: 26148272
DOI: 10.1371/journal.pone.0132506 -
Journal of Cellular and Molecular... Dec 2012Mesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and... (Review)
Review
Mesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and inflammatory diseases, although these cells remain heterogeneous and necessitate a better biological characterization. We and others recently described that MSC originate from two types of perivascular cells, namely pericytes and adventitial cells and contain the in situ counterpart of MSC in developing and adult human organs, which can be prospectively purified using well defined cell surface markers. Pericytes encircle endothelial cells of capillaries and microvessels and express the adhesion molecule CD146 and the PDGFRβ, but lack endothelial and haematopoietic markers such as CD34, CD31, vWF (von Willebrand factor), the ligand for Ulex europaeus 1 (UEA1) and CD45 respectively. The proteoglycan NG2 is a pericyte marker exclusively associated with the arterial system. Besides its expression in smooth muscle cells, smooth muscle actin (αSMA) is also detected in subsets of pericytes. Adventitial cells surround the largest vessels and, opposite to pericytes, are not closely associated to endothelial cells. Adventitial cells express CD34 and lack αSMA and all endothelial and haematopoietic cell markers, as for pericytes. Altogether, pericytes and adventitial perivascular cells express in situ and in culture markers of MSC and display capacities to differentiate towards osteogenic, adipogenic and chondrogenic cell lineages. Importantly, adventitial cells can differentiate into pericyte-like cells under inductive conditions in vitro. Altogether, using purified perivascular cells instead of MSC may bring higher benefits to regenerative medicine, including the possibility, for the first time, to use these cells uncultured.
Topics: Adipose Tissue; Adventitia; Antigens; Biomarkers; CD146 Antigen; Cell Differentiation; Cell Lineage; Cell Transplantation; Cells, Cultured; Humans; Membrane Proteins; Mesenchymal Stem Cells; Pericytes; Proteoglycans; Receptor, Platelet-Derived Growth Factor beta; Regenerative Medicine
PubMed: 22882758
DOI: 10.1111/j.1582-4934.2012.01617.x -
JACC. Cardiovascular Imaging Feb 2009
Topics: Adipose Tissue; Cardiovascular Diseases; Carotid Arteries; Carotid Artery Diseases; Connective Tissue; Humans; Predictive Value of Tests; Risk Assessment; Risk Factors; Tunica Intima; Tunica Media; Ultrasonography
PubMed: 19356554
DOI: 10.1016/j.jcmg.2008.11.005 -
Annual Review of Physiology 2013The vascular adventitia acts as a biological processing center for the retrieval, integration, storage, and release of key regulators of vessel wall function. It is the... (Review)
Review
The vascular adventitia acts as a biological processing center for the retrieval, integration, storage, and release of key regulators of vessel wall function. It is the most complex compartment of the vessel wall and is composed of a variety of cells, including fibroblasts, immunomodulatory cells (dendritic cells and macrophages), progenitor cells, vasa vasorum endothelial cells and pericytes, and adrenergic nerves. In response to vascular stress or injury, resident adventitial cells are often the first to be activated and reprogrammed to influence the tone and structure of the vessel wall; to initiate and perpetuate chronic vascular inflammation; and to stimulate expansion of the vasa vasorum, which can act as a conduit for continued inflammatory and progenitor cell delivery to the vessel wall. This review presents the current evidence demonstrating that the adventitia acts as a key regulator of vascular wall function and structure from the outside in.
Topics: Adventitia; Animals; Blood Vessels; Fibroblasts; Humans; Macrophages; Stem Cells; Stress, Physiological; Vasa Vasorum
PubMed: 23216413
DOI: 10.1146/annurev-physiol-030212-183802 -
Arteriosclerosis, Thrombosis, and... Jul 2011Conventional views of the tunica adventitia as a poorly organized layer of vessel wall composed of fibroblasts, connective tissue, and perivascular nerves are undergoing... (Review)
Review
Conventional views of the tunica adventitia as a poorly organized layer of vessel wall composed of fibroblasts, connective tissue, and perivascular nerves are undergoing revision. Recent studies suggest that the adventitia has properties of a stem/progenitor cell niche in the artery wall that may be poised to respond to arterial injury. It is also a major site of immune surveillance and inflammatory cell trafficking and harbors a dynamic microvasculature, the vasa vasorum, that maintains the medial layer and provides an important gateway for macrophage and leukocyte migration into the intima. In addition, the adventitia is in contact with tissue that surrounds the vessel and may actively participate in exchange of signals and cells between the vessel wall and the tissue in which it resides. This brief review highlights recent advances in our understanding of the adventitia and its resident progenitor cells and discusses progress toward an integrated view of adventitial function in vascular development, repair, and disease.
Topics: Animals; Cell Communication; Connective Tissue; Humans; Inflammation Mediators; Phenotype; Signal Transduction; Stem Cell Niche; Stem Cells; Vascular Diseases
PubMed: 21677296
DOI: 10.1161/ATVBAHA.110.221549 -
Plastic Surgery (Oakville, Ont.) May 2022Surgical simulation of microvascular anastomosis has become increasingly popular. There are several living and silicone models available. Current silicone models fail to...
PURPOSE
Surgical simulation of microvascular anastomosis has become increasingly popular. There are several living and silicone models available. Current silicone models fail to accurately reproduce a vessel's loose adventitial layer, which may lead to the development of improper microsurgical technique. Our purpose is to create a realistic 3-dimensional microsurgical simulator that incorporates an adventitial vessel layer for higher fidelity manipulation of vessels.
METHODS
A microvascular anastomosis simulator was manufactured using metal moulds and inorganic materials. Synthetic tubing was created with a metal cylinder, 1.65 mm in diameter, painted with 2 sequential layers of silicon with a shore hardness of 2A. Silicone was allowed to fully cure in-between layers. Vessel adventitia was created with a 100-micron polyester mesh adhered to the silicone vessel exterior. Once dry, the synthetic tube is removed from the metal cylinder is then clipped to reveal the inner lumen. Both Resident and attending physicians evaluated the model with and without the adventitial layer and completed a questionnaire.
RESULTS
Grasping and manipulation of the vessel were scored on Average score 4.5 and 3 out of 5, with adventitia and without, respectively ( = .00906). Usefulness as a teaching tool was scored on average 4.9 and 4.2, with adventitia and without, respectively ( = .0232). The analysis included: simulation realism, educational utility, and overall satisfaction. Responses in all domains were favourable, suggesting the utility of this model.
CONCLUSION
We created a realistic, high fidelity microvascular anastomosis simulator that is low cost and easily reproducible. Initial feedback is encouraging regarding realism, educational utility, and overall usefulness. Further validation is required to assess its effectiveness in resident education and skill transfer to the operating room.
PubMed: 35572089
DOI: 10.1177/22925503211003835