A novel FPCL model producing directional contraction through induction of fibroblast alignment by biphasic pulse direct current electric field
A novel FPCL model producing directional contraction through induction of fibroblast alignment by biphasic pulse direct current electric field
复制标题
通过双相脉冲直流电场诱导成纤维细胞排列产生定向收缩的新型 FPCL 模型
DOI：
10.1016/j.yexcr.2018.09.003
复制
发表时间：
2018-10-15
影响因子：
3.7
通讯作者：
Zhang, Jiaping
中科院分区：
文献类型：
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作者：
Liu, Jie;Guo, Xiaowei;Zhang, Jiaping
虽然成纤维细胞与瘢痕张力线的平行排列已在体内得到证实，但由于缺乏有效的体外模型，瘢痕挛缩如何产生定向收缩在很大程度上仍不清楚。成纤维细胞填充的胶原晶格（FPCL），一个广泛使用的体外模型，不能模拟瘢痕挛缩，因为它产生同心收缩与成纤维细胞的随机取向。我们假设，一种新的FPCL模型与成纤维细胞对齐可能会产生定向收缩，然后更好地模拟瘢痕挛缩。在这里，我们表明，虽然直流电场（DCEFs）使成纤维细胞垂直于场矢量对齐，它也促进FPCL中的成纤维细胞的趋电迁移。相比之下，双相脉冲直流电场（BPDCEFs），其特征在于EF方向的周期性逆转，取消了趋电迁移，但诱导成纤维细胞排列的脉冲频率依赖性的方式。具体而言，BPDCEF在0.0002 Hz的脉冲频率下诱导成纤维细胞排列与DCEF在相同场强（300 mV/mm）下诱导的成纤维细胞排列相当，导致FPCL沿细胞排列方向沿着收缩增强。经BPDCEF预处理的FPCL呈椭圆形收缩，而对照组FPCL呈同心圆状收缩。进一步的研究表明，F-actin的重新分布是BPDCEF诱导成纤维细胞排列的关键机制。细胞松弛素D，一种肌动蛋白动力学抑制剂，取消F-肌动蛋白的重新分布，并显着抑制成纤维细胞排列和FPCL的定向收缩。重要的是，BPDCEF显着增加成纤维细胞中的RhoA活性，而这种反应被C3转移酶预处理减弱，C3转移酶是RhoA的有效抑制剂，引起F-肌动蛋白解聚和肌动蛋白丝束随机分布。总之，我们的研究表明成纤维细胞的方向在瘢痕挛缩中起着至关重要的作用，并提供了一种新的FPCL模型，可能是可行的和有效的研究瘢痕挛缩在体外。
Although parallel alignment of fibroblasts to the tension lines of scar has been evidenced in vivo, how scar contracture generates directional contraction remains largely unclear due to the lack of effective in vitro model. Fibroblast populated collagen lattice (FPCL), a widely used in vitro model, fails to mimic scar contracture since it produces concentric contraction with the random orientation of fibroblast. We hypothesized that a novel FPCL model with fibroblast alignment might produce directional contraction and then simulate scar contracture better. Here, we showed that although direct current electric fields (DCEFs) enabled fibroblasts aligned perpendicularly to the field vector, it also promoted electrotactic migration of fibroblast in FPCL. By contrast, biphasic pulse direct current electric fields (BPDCEFs), featured by reversal of the EF direction periodically, abolished the electrotactic migration, but induced fibroblast alignment in a pulse frequency dependent manner. Specifically, BPDCEF at a pulse frequency of 0.0002 Hz induced fibroblast alignment comparable to that induced by DCEF under the same field strength (300 mV/mm), leading to an enhanced contraction of FPCL along the direction of cell alignment. FPCL pretreated by BPDCEF showed an elliptical contraction whereas it was concentric in control FPCL. Further study revealed that F-actin redistributions acted as a key mechanism for the induction of fibroblasts alignment by BPDCEF. Cytochalasin D, an inhibitor of actin dynamics, abolished F-actins redistribution, and significantly suppressed the fibroblasts alignment and the directional contraction of FPCL. Importantly, BPDCEF significantly increased RhoA activity in fibroblasts, while this response was attenuated by C3 transferase pre-treatment, a potent inhibitor of RhoA, caused F-actin depolymerization and actin filament bundle randomly distributed. Taken together, our study suggests a crucial role for fibroblast orientation in scar contracture, and provides a novel FPCL model that may be feasible and effective for investigating scar contracture in vitro.