scholarly journals Quantification of Oscillatory Shear Stress from Reciprocating CSF Motion on 4D Flow Imaging

Author(s):  
S. Yamada ◽  
H. Ito ◽  
M. Ishikawa ◽  
K. Yamamoto ◽  
M. Yamaguchi ◽  
...  
2020 ◽  
Vol 74 ◽  
pp. 232-243
Author(s):  
Sébastien Levilly ◽  
Marco Castagna ◽  
Jérôme Idier ◽  
Félicien Bonnefoy ◽  
David Le Touzé ◽  
...  

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Islam Mohamed ◽  
Sheena Thomas ◽  
Kimberly Rooney ◽  
Roy Sutliff ◽  
Nick Willett ◽  
...  

Introduction: Shear stress forces play an integral role in dictating the endothelial cell (EC) response to changes in blood flow, pro-inflammatory response and hence development of atherosclerosis. Previously, our group has identified EC microRNA-155 (miR-155) as one of the key signature dysregulated miRNAs in areas of chronic low magnitude oscillatory shear stress (OSS) in vasculature and OSS models of in-vitro. Hypothesis: we hypothesized that acute induction of OSS mediates EC oxidative stress, inflammation and dysfunction, via dysregulation of EC miR-155. Methods: 12-week old C57B/6J mice were subjected to abdominal aortic coarctation (AAC), a unique model of acute induction of OSS, for 3 days and downstream segments of acute OSS were compared to upstream unidirectional shear stress (USS) segments of the thoracic aorta. Results: Acute OSS resulted in down regulation of EC miR-155 expression and inverse upregulation of EC RhoA and Myosin light chain kinase (MYLK), known targets of miR-155-mediated EC cytoskeleton organization, in OSS segments compared with USS. This was associated with impaired EC dependent relaxation, differential contractile response to phenylephrine, and loss of EC barrier function as evaluated by extravasation of Evans-blue dye assay. In parallel, En-face immunohistochemical staining also showed increased expression of EC nitric oxide synthase (eNOS) along with increased levels of reactive oxygen species (ROS) and nitrotyrosine (NY) formation in OSS segments compared with USS. Conclusions: Together, our studies shed light on the early changes in EC response to acute induction of OSS and resulting down-regulation of EC mir-155, including; oxidative/inflammatory stress, EC dysfunction, loss of barrier function and cytoskeletal changes. Despite the early upregulation of eNOS, it could also potentially synergize with the activation of the RhoA-MYLK pathway in EC oxidative (ROS/NY)/inflammatory stress and associated EC dysfunction. Further studies are in progress to dissect the interplay between these different pathways and their causal relationships as downstream targets of EC miR-155.


2012 ◽  
Vol 97 (Suppl 1) ◽  
pp. A129.3-A130
Author(s):  
MM Gedicke ◽  
A Pitcher ◽  
A Barker ◽  
J Bock ◽  
R Lorenz ◽  
...  

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Katherine Quigley ◽  
Karen Fang ◽  
Nelson Jen ◽  
Rongsong Li ◽  
Tzung Hsiai

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Wakako Takabe ◽  
Chih-Wen Ni ◽  
Dong Ju Son ◽  
Noah Alberts-Grill ◽  
Hanjoong Jo

Recently, we have shown that disturbed flow, characterized by low and oscillatory shear stress, caused by a partial ligation of mouse left carotid artery (LCA) rapidly induces atherosclerosis. Using the partial ligation model and genome-wide microarray study with aortic endothelial RNAs obtained directly from the flow-disturbed carotid arteries, we previously identified mechanosensitive genes in mouse endothelial RNA including LIM domain only 4 ( lmo4 ). Here we report that LMO4 is a shear-sensitive protein that regulates endothelial inflammation. Lmo4 was up-regulated by disturbed flow in mouse LCA compared to the contralateral right CA (RCA) exposed to stable flow. At protein levels, LMO4 expression was significantly higher not only in LCA in our surgical model but also in the lesser curvature (flow-disturbed and athero-prone region of mouse aortic arch) compared to the greater curvature (stable-flow and ather-protected region). In addition, immunohistochemical staining of LMO4 in human coronary arteries revealed that its expression is detectable only in intimal endothelial cells, but not in medial cells. While LMO4 is known as a potential oncogene and associated with growth, migration and invasion of breast cancer cells, its role in cardiovascular system is not known to our knowledge. We tested a hypothesis that LMO4 is a mechanosensitive gene and plays a critical role in regulation of endothelial cell biology. LMO4 protein expression was robustly induced by oscillatory shear stress (OS) compared to laminar shear (LS) in human umbilical vein endothelial cells (HUVEC). Treatment of HUVEC with siRNA against LMO4 significantly inhibited OS-induced inflammation and migration, but not apoptosis and cell cycle progression. Further, LMO4 siRNA treatment significantly blunted expression of VCAM-1 and interleukin-8 induced by OS in endothelial cells. These results suggest that LMO4 is a shear-induced gene that plays a critical role in OS-induced endothelial inflammation and migration, and potentially in atherosclerosis.


2018 ◽  
Vol 10 (2) ◽  
pp. 255
Author(s):  
M.A. Isorni ◽  
S. Monnot ◽  
S. Hascoet

2020 ◽  
Vol 89 ◽  
pp. 107048
Author(s):  
Jian Zhao ◽  
Xiaoqiang Quan ◽  
Zhouliang Xie ◽  
Leilei Zhang ◽  
Zhiwei Ding

2019 ◽  
Vol 20 (Supplement_2) ◽  
Author(s):  
M Guglielmo ◽  
A Baggiano ◽  
G Muscogiuri ◽  
A I Guaricci ◽  
D Andreini ◽  
...  

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