EphB4 Expressing Stromal Cells Exhibit an Enhanced Capacity for Hematopoietic Stem Cell Maintenance

Autor: Louise E. Purton, Sharon Paton, Romana Panagopoulos, Koichi Matsuo, John D. Hayball, Andrew C.W. Zannettino, Thao Nguyen, Agnieszka Arthur, Stan Gronthos
Přispěvatelé: Nguyen, Thao M, Arthur, Agnieszka, Panagopoulos, Romana, Paton, Sharon, Hayball, John D, Zannettino, Andrew CW, Purton, Louise E, Matsuo, Koichi, Gronthos, Stan
Rok vydání: 2014
Předmět:
Zdroj: Stem cells (Dayton, Ohio). 33(9)
ISSN: 1549-4918
Popis: The tyrosine kinase receptor, EphB4, mediates cross-talk between stromal and hematopoietic populations during bone remodeling, fracture repair and arthritis, through its interactions with the ligand, ephrin-B2. This study demonstrated that transgenic EphB4 mice (EphB4 Tg), over-expressing EphB4 under the control of collagen type-1 promoter, exhibited higher frequencies of osteogenic cells and hematopoietic stem/progenitor cells (HSC), correlating with a higher frequency of long-term culture-initiating cells (LTC-IC), compared with wild type (WT) mice. EphB4 Tg stromal feeder layers displayed a greater capacity to support LTC-IC in vitro, where blocking EphB4/ephrin-B2 interactions decreased LTC-IC output. Similarly, short hairpin RNA-mediated EphB4 knockdown in human bone marrow stromal cells reduced their ability to support high ephrin-B2 expressing CD34+ HSC in LTC-IC cultures. Notably, irradiated EphB4 Tg mouse recipients displayed enhanced bone marrow reconstitution capacity and enhanced homing efficiency of transplanted donor hematopoietic stem/progenitor cells relative to WT controls. Studies examining the expression of hematopoietic supportive factors produced by stromal cells indicated that CXCL12, Angiopoietin-1, IL-6, FLT-3 ligand, and osteopontin expression were more highly expressed in EphB4 Tg stromal cells compared with WT controls. These findings indicate that EphB4 facilitates stromal-mediated support of hematopoiesis, and constitute a novel component of the HSC niche. Stem Cells 2015;33:2838—2849
Databáze: OpenAIRE