title: The effects of actin cytoskeleton perturbation on keratin intermediate filament formation in mesenchymal stem/stromal cells.
abstract: F-actin plays a crucial role in composing the three-dimensional cytoskeleton and F-actin depolymerization alters fate choice of mesenchymal stem/stromal cells (MSCs). Here, we investigated differential gene expression and subsequent physiological changes in response to F-actin perturbation by latrunculin B in MSCs. Nineteen genes were down-regulated and 27 genes were up-regulated in the first 15 min after F-actin depolymerization. Functional enrichment analysis revealed that five genes involved in keratin (KRT) intermediate filaments clustering in the chromosome 17q21.2 region, i.e., KRT14, KRT19, KRT34, KRT-associated protein (KRTAP) 1-5, and KRTAP2-3, were strongly up-regulated. Transcription factor prediction identified NKX2.5 as the potential transcription factor to control KRT19, KRT34, KRTAP1-5, and KRTAP2-3; and indeed, the protein level of NKX2.5 was markedly increased in the nuclear fraction within 15 min of F-actin depolymerization. The peak of keratin intermediate filament formation was 1 h after actin perturbation, and the morphological changes showed by decrease in the ratio of long-axis to short-axis diameter in MSCs was observed after 4 h. Together, F-actin depolymerization rapidly triggers keratin intermediate filament formation by turning on keratin-related genes on chromosome 17q21.2. Such findings offer new insight in lineage commitment of MSCs and further scaffold design in MSC-based tissue engineering.
authors: Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
authors: Tzu-Hao
authors: TH
authors: Chang
authors: Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan; Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan.
authors: Hsien-Da
authors: HD
authors: Huang
authors: Center for Stem Cell Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors: Wei-Kee
authors: WK
authors: Ong
authors: Center for Stem Cell Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors: Yun-Ju
authors: YJ
authors: Fu
authors: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors: Oscar K
authors: OK
authors: Lee
authors: Institute of Engineering in Medicine, University of California at San Diego, La Jolla, CA, USA; Departments of Bioengineering and Medicine, University of California at San Diego, La Jolla, CA, USA.
authors: Shu
authors: S
authors: Chien
authors: Center for Stem Cell Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan; Department of Ophthalmology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan. Electronic address: wh9801@yahoo.com.tw.
authors: Jennifer H
authors: JH
authors: Ho
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002478:Cells, Cultured; D006801:Humans; D007382:Intermediate Filaments / Q000378:metabolism*; D007633:Keratins / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism*; D053778:Thiazolidines / Q000494:pharmacology
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D053778:Thiazolidines; D007633:Keratins; C037068:latrunculin B
keywords: Chromosome 17q21.2; F-actin depolymerization; Intermediate filaments; Keratin; Mesenchymal stem cells (MSCs); NK2 homeobox 5 (NKX2.5)