Force-dependent bond dissociation govern rolling of HL-60 cells through E-selectin
Force-dependent bond dissociation govern rolling of HL-60 cells through E-selectin
复制标题
力依赖性键解离通过 E-选择素控制 HL-60 细胞的滚动
DOI：
10.1016/j.yexcr.2012.05.018
复制
发表时间：
2012-08-15
影响因子：
3.7
通讯作者：
Wu, Jianhua
中科院分区：
文献类型：
--
作者：
Li, Quhuan;Fang, Ying;Wu, Jianhua
E-选择素介导的循环白细胞在血管表面的滚动是炎症反应和淋巴细胞归巢的关键起始事件。这一事件不仅取决于粘附分子的特定相互作用，而且取决于血流的血液动力学。关于壁面剪切应力或剪切速率是否调节滚动仍然知之甚少。本文用流动室技术，在无或有3%Ficoll的培养基中，在0.05 - 0.7dyn/cm（2）的不同壁面切应力下，测定了运输、切应力和细胞变形对未固定和固定的HL-60细胞在E-选择素上滚动的影响。结果表明，随着轧制力的增加，轧制过程呈现出先加速，然后在初始剪切阈值约0.1dyn/cm（2）处出现减速阶段，最后在最佳剪切阈值约0.35dyn/cm（2）处又回到加速阶段的三阶段过程。捕获键状态完全反映在滚动行为中，如系绳寿命、电池停止时间和滚动速度，这意味着控制滚动的主导因素是力。初始剪切阈值可能是维持静止滚动所需的最低壁面剪应力水平，最佳剪切阈值将使滚动达到最稳定和规则。这些发现有力地阐明了通过E-选择素的流动增强滚动的捕获键机制，因为较长的键寿命导致较慢和更稳定的滚动。(C)2012 Elsevier Inc. All rights reserved.
E-selectin-mediated rolling on vascular surface of circulating leukocyte on vascular surface is a key initial event during inflammatory response and lymphocyte homing. This event depends not only on the specific interactions of adhesive molecules but also on the hemodynamics of blood flow. Little is still understood about whether wall shear stress or shear rate regulates the rolling. With flow chamber techniques, we here measured the effects of transport, shear stress and cell deformation on rolling of both unfixed and fixed HL-60 cells on E-selectin either in the absence or in the presence of 3% Ficoll in medium at various wall shear stresses from 0.05 to 0.7 dyn/cm(2). The results demonstrated a triphasic force-dependent rolling, that is, as increasing of force, the rolling would be accelerated firstly, then followed a decelerating phase occurred at the initial shear threshold of about 0.1 dyn/cm(2), and lastly returned to an accelerating process starting at the optimal shear threshold of 0.35 dyn/cm(2) approximately. The catch bond regime was completely reflected to rolling behaviors, such as tether lifetime, cell stop time and rolling velocity, meaning that the dominant factor to govern rolling is force. The initial shear threshold might be the minimum level of wall shear stress to sustain a stationary rolling, and the optimal shear threshold would make rolling to the most stable and regular. These findings strongly elucidate the catch bond mechanism for flow-enhanced rolling through E-selectin since longer bond lifetimes led to slower and stabler rolling. (C) 2012 Elsevier Inc. All rights reserved.