Impact of Bi-Axial Shear on Atherogenic Gene Expression by Endothelial Cells

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• 作者：Amlan Chakraborty ; Sutirtha Chakraborty…
• 关键词：Computational fluid dynamics ; Oscillatory shear stress ; Directionality of shear ; Endothelial cellular responses ; Atherogenic gene expression ; Statistical significance
• 刊名：Annals of Biomedical Engineering
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：44
• 期：10
• 页码：3032-3045
• 全文大小：3,656 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine
  Biomedicine
  Biomedical Engineering
  Biophysics and Biomedical Physics
  Mechanics
  Biochemistry
  
• 出版者：Springer Netherlands
• ISSN：1573-9686
• 卷排序：44

文摘

This study demonstrated the effects of the directionality of oscillatory wall shear stress (WSS) on proliferation and proatherogenic gene expression (I-CAM, E-Selectin, and IL-6) in the presence of inflammatory mediators leukotriene B₄ (LTB₄) and bacterial lipopolysaccharide (LPS) from endothelial cells grown in an orbiting culture dish. Computational fluid dynamics (CFD) was applied to quantify the flow in the dish, while an analytical solution representing an extension of Stokes second problem was used for validation. Results indicated that WSS magnitude was relatively constant near the center of the dish and oscillated significantly (0–0.9 Pa) near the side walls. Experiments showed that LTB₄ dominated the shear effects on cell proliferation and area. Addition of LPS didn’t change proliferation, but significantly affected cell area. The expression of I-CAM1, E-Selectin and IL-6 were altered by directional oscillatory shear index (DOSI, a measure of the biaxiality of oscillatory shear), but not shear magnitude. The significance of DOSI was further reinforced by the strength of its interactions with other atherogenic factors. Hence, directionality of shear appears to be an important factor in regulating gene expression and provides a potential explanation of the propensity for increased vascular lesions in regions in the arteries with oscillating biaxial flow.