Schematic representation of the main components present
in the blastocyst and bone marrow microenvironment. (a)
Preimplanted embryo (blastocyst) composed by the inner cell mass
(ICM) and the trophectoderm cell layer (TE). Abbreviations:
FGF2/FGF, fibroblast growth factor 2 and 1; FGFR-1, fibroblast
growth factor receptor-1; LIF, leukemia inhibitory factor; LIFR,
leukemia inhibitory factor receptor; JAK, JAK kinase; STAT,
transcription factor STAT; STATa, transcription factor STAT
activated. (b) Adult bone marrow
composed by HSCs, hematopoietic stem cells; MSCs, mesenchymal
stem cells; and other cellular components such as adipocytes,
stromal cells, hematopoietic lineage, macrophages, dendritic
cells, osteoblasts, and adipoblasts. In addition, it is composed also
by extracellular matrix proteins such as types I and II collagen,
tenascin, laminin, and the proteoglycan heparan sulphate.
Abbreviations: SDF-1, stroma-derived factor-1;
SCF, stem cell factor; CAM, cell adhesion molecule.