Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany.
PLoS One. 2013 Jul 18;8(7):e69128. doi: 10.1371/journal.pone.0069128. Print 2013.
Cells can adapt to hypoxia by various mechanisms. Yet, hypoxia-induced effects on the cytoskeleton-based cell architecture and functions are largely unknown. Here we present a comprehensive analysis of the architecture and function of L929 fibroblasts under hypoxic conditions (1% O2). Cells cultivated in hypoxia showed striking morphological differences as compared to cells cultivated under normoxic conditions (20% O2). These changes include an enlargement of cell area and volume, increased numbers of focal contacts and loss of cell polarization. Furthermore the β- and γ-actin distribution is greatly altered. These hypoxic adjustments are associated with enhanced cell spreading and a decline of cell motility in wound closure and single cell motility assays. As the hypoxia-inducible factor-1α (HIF-1α) is stabilised in hypoxia and plays a pivotal role in the transcriptional response to changes in oxygen availability we used an shRNA-approach to examine the role of HIF-1α in cytoskeleton-related architecture and functions. We show that the observed increase in cell area, actin filament rearrangement, decrease of single cell migration in hypoxia and the maintenance of p-cofilin levels is dependent on HIF-1α stabilisation.
细胞可以通过各种机制来适应缺氧。然而，缺氧对基于细胞骨架的细胞结构和功能的影响在很大程度上是未知的。在这里，我们对 L929 成纤维细胞在缺氧条件（1% O2）下的结构和功能进行了全面分析。与在常氧条件（20% O2）下培养的细胞相比，在缺氧条件下培养的细胞表现出明显的形态差异。这些变化包括细胞面积和体积的增大、焦点接触数量的增加以及细胞极化的丧失。此外，β-和γ-肌动蛋白的分布也发生了很大的改变。这些缺氧的调节与细胞铺展能力的增强以及在划痕愈合和单细胞迁移实验中细胞迁移能力的下降有关。由于缺氧诱导因子-1α（HIF-1α）在缺氧条件下稳定存在，并在转录水平上对氧可用性的变化起关键作用，我们使用 shRNA 方法来研究 HIF-1α在细胞骨架相关结构和功能中的作用。我们发现，细胞面积的增加、肌动蛋白丝的重排、缺氧时单细胞迁移的减少以及 p-cofilin 水平的维持都依赖于 HIF-1α的稳定。
