Get access
Journal of Cellular Biochemistry

Caveolin-1 regulates proliferation and osteogenic differentiation of human mesenchymal stem cells

Authors

  • Natasha Baker,

    1. Cartilage Biology and Orthopaedics Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892
    2. Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
    Search for more papers by this author
  • Guofeng Zhang,

    1. Biomedical Engineering and Physical Science Shared Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892
    Search for more papers by this author
  • Yang You,

    1. Cartilage Biology and Orthopaedics Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892
    Search for more papers by this author
  • Rocky S. Tuan

    Corresponding author
    1. Cartilage Biology and Orthopaedics Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892
    2. Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219
    • Department of Orthopaedic Surgery, Center for Cellular and Molecular Engineering, School of Medicine, University of Pittsburgh, 450 Technology Drive, Room 221, Pittsburgh, PA 15219-3143.
    Search for more papers by this author

  • The authors have no conflicts of interest to declare.

Abstract

Caveolin-1 is a scaffolding protein of cholesterol-rich caveolae lipid rafts in the plasma membrane. In addition to regulating cholesterol transport, caveolin-1 has the ability to bind a diverse array of cell signaling molecules and regulate cell signal transduction in caveolae. Currently, there is little known about the role of caveolin-1 in stem cells. It has been reported that the caveolin-1 null mouse has an expanded population of cells expressing stem cell markers in the gut, mammary gland, and brain, suggestive of a role for caveolin-1 in stem cell regulation. The caveolin-1 null mouse also has increased bone mass and an increased bone formation rate, and its bone marrow-derived mesenchymal stem cells (MSCs) have enhanced osteogenic potential. However, the role of caveolin-1 in human MSC osteogenic differentiation remains unexplored. In this study, we have characterized the expression of caveolin-1 in human bone marrow derived MSCs. We show that caveolin-1 protein is enriched in density gradient-fractionated MSC plasma membrane, consisting of ∼100 nm diameter membrane-bound vesicles, and is distributed in a punctate pattern by immunofluoresence localization. Expression of caveolin-1 increases in MSCs induced to undergo osteogenic differentiation, and siRNA-mediated knockdown of caveolin-1 expression enhances MSC proliferation and osteogenic differentiation. Taken together, these findings suggest that caveolin-1 normally acts to regulate the differentiation and renewal of MSCs, and increased caveolin-1 expression during MSC osteogenesis likely acts as a negative feedback to stabilize the cell phenotype. J. Cell. Biochem. 113: 3773–3787, 2012. © 2012 Wiley Periodicals, Inc.

Get access to the full text of this article

Ancillary