Hypoxia modulates fibroblastic architecture, adhesion and migration: a role for HIF-1α in cofilin regulation and cytoplasmic actin distribution

• Published in: PloS one 2013-07, Vol.8 (7), p.e69128-e69128
• Main Authors: Vogler, Melanie, Vogel, Sabine, Krull, Sabine, Farhat, Katja, Leisering, Pia, Lutz, Susanne, Wuertz, Christina M, Katschinski, Dörthe M, Zieseniss, Anke
• Format: Article
• Language: English
• Subjects: Actin; Actin Depolymerizing Factors - metabolism; Actins - metabolism; Analysis of Variance; Animals; Architecture; Biology; Cell adhesion & migration; Cell Adhesion - physiology; Cell Hypoxia - physiology; Cell Line, Tumor; Cell migration; Cell Movement - physiology; Cell Size; Cell spreading; Cofilin; Cytoplasm - metabolism; Cytoskeleton; Enlargement; Fibroblasts; Fibroblasts - cytology; Fibroblasts - physiology; Flow Cytometry; Fluorescence; Gene Knockdown Techniques; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Hypoxia-inducible factors; Immunoblotting; Kinases; Medicine; Mice; Morphology; Motility; Oxygen; Phosphorylation; Physics; Physiology; Proteins; Pulmonary arteries; Rodents; Studies; Transcription; Wound healing; Wounds
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0069128

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.