Bo Ling^1,#, Daoxi Lei^1,#, Juhui Qiu¹, Kang Zhang¹, Hao Chen^2,*, Yeqi Wang¹, Zhiyi Ye¹, Guixue Wang^*

Molecular & Cellular Biomechanics, Vol.14, No.4, pp. 197-211, 2017, DOI:10.3970/mcb.2017.014.197

Abstract Shear stress and oxidized low-density lipoprotein (oxLDL) caused by abnormal blood is critical to angiogenesis for atherosclerosis. However, the mechanism in shear stress or ox-LDL regulated angiogenesis is still not well understood. There is the hypothesis that shear stress or oxLDL regulates angiogenesis through the vascular endothelial growth factor (VEGF) signaling pathway. It is discovered that both high shear stress and low concentration of oxLDL contribute to angiogenesis, which is inhibited once the VEGF or VEGFR expression is knocked down. The expression of p-FAK and p-paxillin is regulated by the VEGF/VEGFR signal axis. VEGFR2, p-FAK, p-paxillin and VEGFR1 are VEGF-responsive… More >

Yidan Chen^#,1, Kang Zhang^#,1, Juhui Qiu¹, Shicheng He¹, Junyang Huang², Lu Huang¹, Dongyu Jia³, Bo Ling¹, Da Sun⁴, Xiang Xie¹, Tieying Yin^*,1, Guixue Wang^*,1

Molecular & Cellular Biomechanics, Vol.14, No.2, pp. 83-100, 2017, DOI:10.3970/mcb.2017.014.081

Abstract Abnormal shear stress in the blood vessel is an important stimulating factor for the formation of angiogenesis and vulnerable plaques. This paper intended to explore the role of shear stress-regulated Id1 in angiogenesis. First, we applied a carotid artery ring ligation to create local stenosis in ApoE^-/- mice. Then, 3D geometry of the vessel network was reconstructed based on MRI, and our analysis of computational fluid dynamics revealed that wall shear stress of the proximal region was much higher than that of the distal region. In addition, results from histological staining of the proximal region found more vulnerable-probe plaques with… More >

Zhen Liu¹, Yan Cai¹, Guo-Zhong Chen², Guang-Ming Lu, Zhi-Yong Li^1,3,*

Molecular & Cellular Biomechanics, Vol.14, No.1, pp. 19-31, 2017, DOI:10.3970/mcb.2017.014.019

Abstract Background: Intracranial aneurysm (IA) can be commonly found in the circle of Willis (CoW), and a higher morbidity of IA is found to be associated with a higher percentage of an incomplete CoW. Hemodynamic factors are believed to play an important role in aneurysm formation. However, how the anatomical variations in CoW lead to hemodynamic difference and what hemodynamic parameters play important roles in aneurysm formation have not been quantified and assessed. Methods and Results: Thirty patients were included and based one computed tomography angiography, they were divided into three groups (10 patients per group): a normal group (normal CoW… More >

Jianhang Du^1,2,3, Liang Wang⁴

Molecular & Cellular Biomechanics, Vol.12, No.4, pp. 249-263, 2015, DOI:10.3970/mcb.2015.012.249

Abstract Growing evidences suggest that long-term enhanced external counterpulsation (EECP) treatment can inhibit the initiation of atherosclerotic lesion by improving the hemodynamic environment in aortas. However, whether this kind procedure will intervene the progression of advanced atherosclerotic plaque remains elusive and causes great concern in its clinical application presently. In the current paper, a pilot study combining animal experiment and numerical simulation was conducted to investigate the acute mechanical stress variations during EECP intervention, and then to assess the possible chronic effects. An experimentally induced hypercholesterolemic porcine model was developed and the basic hemodynamic measurement was performed in vivo before and… More >

Hana Chang^*, Melissa L. Knothe Tate^∗,†,‡

Molecular & Cellular Biomechanics, Vol.8, No.4, pp. 297-318, 2011, DOI:10.3970/mcb.2011.008.297

Abstract In the preceding study (Part A), we showed that prescribed seeding conditions as well as seeding density can be used to subject multipotent stem cells (MSCs) to volume changing stresses and that changes in volume of the cell are associated with changes in shape, but not volume, of the cell nucleus. In the current study, we aim to control the mechanical milieu of live cells using these prescribed seeding conditions concomitant to delivery of shape changing stresses via fluid flow, while observing adaptation of the cytoskeleton, a major cellular transducer that modulates cell shape, stiffness and remodeling. We hypothesize that… More >

Biyue Liu^∗, Dalin Tang^†

Molecular & Cellular Biomechanics, Vol.8, No.1, pp. 73-90, 2011, DOI:10.3970/mcb.2011.008.073

Abstract The objective of this work is to investigate the effect of non-Newtonian properties of blood on the wall shear stress (WSS) in atherosclerotic coronary arteries using both Newtonian and non-Newtonian models. Numerical simulations were performed to examine how the spatial and temporal WSS distributions are influenced by the stenosis size, blood viscosity, and flow rate. The computational results demonstrated that blood viscosity properties had considerable effect on the magnitude of the WSS, especially where disturbed flow was observed. The WSS distribution is highly non-uniform both temporally and spatially, especially in the stenotic region. The maximum WSS occurred at the proximal… More >

Biyue Liu^∗, Dalin Tang^†

Molecular & Cellular Biomechanics, Vol.7, No.4, pp. 193-202, 2010, DOI:10.3970/mcb.2010.007.193

Abstract A three dimensional mathematical model with a linear plaque growth function was developed to investigate the geometrical adaptation of atherosclerotic plaques in coronary arteries and study the influences of flow wall shear stress (WSS), blood viscosity and the inlet flow rate on the growth of atherosclerotic plaques using computational plaque growth simulations. The simulation results indicated that the plaque wall thickness at the neck of the stenosis increased at a decreasing rate in the atherosclerosis progression. The simulation results also showed a strong dependence of the plaque wall thickness increase on the blood viscosity and the inlet flow rate. The… More >

Colin K. Choi^*, Brian P. Helmke^∗,†

Molecular & Cellular Biomechanics, Vol.5, No.4, pp. 247-258, 2008, DOI:10.3970/mcb.2008.005.247

Abstract Hemodynamic shear stress guides a variety of endothelial phenotype characteristics, including cell morphology, cytoskeletal structure, and gene expression profile. The sensing and processing of extracellular fluid forces may be mediated by mechanotransmission through the actin cytoskeleton network to intracellular locations of signal initiation. In this study, we identify rapid actin-mediated morphological changes in living subconfluent and confluent bovine aortic endothelial cells (ECs) in response to onset of unidirectional steady fluid shear stress (15 dyn/cm²). After flow onset, subconfluent cells exhibited dynamic edge activity in lamellipodia and small ruffles in the downstream and side directions for the first 12 min; activity… More >

Shu Chien^*

Molecular & Cellular Biomechanics, Vol.5, No.1, pp. 1-8, 2008, DOI:10.3970/mcb.2008.005.001

Abstract Fluid shear stress due to blood flow can modulate functions of endothelial cells (ECs) in blood vessels by activating mechano-sensors, signaling pathways, and gene and protein expressions. Laminar shear stress with a definite forward direction causes transient activations of many genes that are atherogenic, followed by their down-regulation; laminar shear stress also up-regulates genes that inhibit EC growth. In contrast, disturbed flow patterns with little forward direction cause sustained activations of these atherogenic genes and enhancements of EC mitosis and apoptosis. In straight parts of the arterial tree, laminar shear stress with a definite forward direction has anti-atherogenic effects. At… More >

Jason W. Triplett^∗, Rita O’Riley^∗, Kristyn Tekulve^∗, Suzanne M. Norvell^∗, Fredrick M. Pavalko^†

Molecular & Cellular Biomechanics, Vol.4, No.1, pp. 13-26, 2007, DOI:10.3970/mcb.2007.004.013

Abstract Maintenance of optimal bone physiology requires the coordinated activity of osteoclasts that resorb old bone and osteoblasts that deposit new bone. Mechanical loading of bone and the resulting movement of interstitial fluid within the spaces surrounding bone cells is thought to play a key role is maintaining optimal bone mass. One way in which fluid movement may promote bone formation is by enhancing osteoblast survival. We have shown previously that application of fluid flow to osteoblasts in vitro confers a protective effect by inhibiting osteoblast apoptosis (Pavalko et al., 2003, J. Cell Physiol., 194: 194-205). To investigate the cellular mechanisms… More >