Embryonic Hematopoietic Progenitor Cells Reside in Muscle before Bone Marrow Hematopoiesis

PLoS One. 2015 Sep 21;10(9):e0138621. doi: 10.1371/journal.pone.0138621. eCollection 2015.

Abstract

In mice, hematopoietic cells home to bone marrow from fetal liver prenatally. To elucidate mechanisms underlying homing, we performed immunohistochemistry with the hematopoietic cell marker c-Kit, and observed c-Kit(+) cells localized inside muscle surrounding bone after 14.5 days post coitum. Flow cytometric analysis showed that CD45(+) c-Kit(+) hematopoietic cells were more abundant in muscle than in bone marrow between 14.5 and 17.5 days post coitum, peaking at 16.5 days post coitum. CD45(+) c-Kit(+) cells in muscle at 16.5 days post coitum exhibited higher expression of Gata2, among several hematopoietic genes, than did fetal liver or bone marrow cells. Colony formation assays revealed that muscle hematopoietic cells possess hematopoietic progenitor activity. Furthermore, exo utero transplantation revealed that fetal liver hematopoietic progenitor cells home to muscle and then to BM. Our findings demonstrate that hematopoietic progenitor cell homing occurs earlier than previously reported and that hematopoietic progenitor cells reside in muscle tissue before bone marrow hematopoiesis occurs during mouse embryogenesis.

MeSH terms

  • Animals
  • Bone Marrow / embryology
  • Bone Marrow / metabolism*
  • Bone Marrow Cells / metabolism
  • Colony-Forming Units Assay
  • Embryonic Stem Cells / metabolism*
  • Female
  • Flow Cytometry
  • GATA2 Transcription Factor / genetics
  • Gene Expression Regulation, Developmental
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Hematopoiesis*
  • Hematopoietic Stem Cells / metabolism*
  • Leukocyte Common Antigens / metabolism
  • Liver / embryology
  • Liver / metabolism
  • Male
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Microscopy, Confocal
  • Muscles / embryology
  • Muscles / metabolism*
  • Organ Culture Techniques
  • Proto-Oncogene Proteins c-kit / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors

Substances

  • GATA2 Transcription Factor
  • Gata2 protein, mouse
  • Green Fluorescent Proteins
  • Proto-Oncogene Proteins c-kit
  • Leukocyte Common Antigens
  • Ptprc protein, mouse

Grants and funding

These authors have no support or funding to report.