Modulation of the extracellular matrix patterning of thrombospondins by actin dynamics and thrombospondin oligomer state.
Modulation of the extracellular matrix patterning of thrombospondins by actin dynamics and thrombospondin oligomer state.
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DOI：
10.1042/bsr20140168
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发表时间：
2015-05-20
影响因子：
4
通讯作者：
Adams JC
中科院分区：
文献类型：
--
作者：
Hellewell AL;Gong X;Schärich K;Christofidou ED;Adams JC
我们报告，血小板反应蛋白（TSP）沉积到细胞外基质（ECM）的图案是由肌动蛋白丝动力学调制。而肌动蛋白依赖的图案是进化保守的，调制的程度与低聚物状态的TSP成反比。血小板反应蛋白（TSP）是一种进化上保守的分泌型糖蛋白，与细胞表面和细胞外基质（ECM）相互作用，在细胞相互作用中具有复杂的作用。与形成网络或原纤维的ECM的结构组分不同，TSP作为纳米级点的阵列沉积到ECM中。对ECM中TSP模式化的细胞和分子机制知之甚少。在本研究中，我们研究了TSP模式化的机制是否涉及肌动蛋白细胞骨架通路或TSP寡聚体状态的细胞来源的ECM。从一套小GTP酶，肌动球蛋白为基础的收缩性，或肌动蛋白微丝的完整性和动力学，细胞松弛素D和jasplakinelatin治疗细胞的药理学抑制剂的测试被确定为导致改变ECM模式的模型TSP 1三聚体。细胞松弛素D的强烈作用表明，控制斑点图案化的机制取决于全球F-肌动蛋白动力学。细胞松弛素D处理后内源性TSP获得类似的空间变化，暗示生理相关性。在与异位表达的TSP相匹配的实验条件下，五聚体TSP 5和果蝇TSP的效应幅度明显低于三聚体TSP 1或二聚体玻璃海鞘TSPA。为了区分蛋白质序列或寡聚体状态的变量，我们产生了新的嵌合五聚体TSP 1。这些蛋白质在ECM内以高于TSP 1三聚体的水平积累，但细胞松弛素D对斑点空间分布的影响降低。这些发现引入了一个新的概念，即F-肌动蛋白动力学调节ECM中TSP的模式，TSP寡聚体状态是这一过程的关键决定因素。
We report that the patterning of thrombospondin (TSP) deposition into the extracellular matrix (ECM) is modulated by actin filament dynamics. Whereas actin-dependence of patterning is evolutionarily conserved, the extent of modulation correlates inversely with the oligomer state of the TSP. Thrombospondins (TSPs) are evolutionarily-conserved, secreted glycoproteins that interact with cell surfaces and extracellular matrix (ECM) and have complex roles in cell interactions. Unlike the structural components of the ECM that form networks or fibrils, TSPs are deposited into ECM as arrays of nanoscale puncta. The cellular and molecular mechanisms for the patterning of TSPs in ECM are poorly understood. In the present study, we investigated whether the mechanisms of TSP patterning in cell-derived ECM involves actin cytoskeletal pathways or TSP oligomer state. From tests of a suite of pharmacological inhibitors of small GTPases, actomyosin-based contractility, or actin microfilament integrity and dynamics, cytochalasin D and jasplakinolide treatment of cells were identified to result in altered ECM patterning of a model TSP1 trimer. The strong effect of cytochalasin D indicated that mechanisms controlling puncta patterning depend on global F-actin dynamics. Similar spatial changes were obtained with endogenous TSPs after cytochalasin D treatment, implicating physiological relevance. Under matched experimental conditions with ectopically-expressed TSPs, the magnitude of the effect was markedly lower for pentameric TSP5 and Drosophila TSP, than for trimeric TSP1 or dimeric Ciona TSPA. To distinguish between the variables of protein sequence or oligomer state, we generated novel, chimeric pentamers of TSP1. These proteins accumulated within ECM at higher levels than TSP1 trimers, yet the effect of cytochalasin D on the spatial distribution of puncta was reduced. These findings introduce a novel concept that F-actin dynamics modulate the patterning of TSPs in ECM and that TSP oligomer state is a key determinant of this process.