Induction of Hematopoietic Differentiation of Mouse Embryonic Stem Cells by an AGM-Derived Stromal Cell Line is Not Further Enhanced by Overexpression of HOXB4

Abstract

Hematopoietic differentiation of embryonic stem (ES) cells can be enhanced by co-culture with stromal cells derived from hematopoietic tissues and by overexpression of the transcription factor HOXB4. In this study, we compare the hematopoietic inductive effects of stromal cell lines derived from different subregions of the embryonic aorta-gonad-mesonephros tissue with the commonly used OP9 stromal cell line and with HOXB4 activation. We show that stromal cell lines derived from the aorta and surrounding mesenchyme (AM) act at an earlier stage of the differentiation process compared with the commonly used OP9 stromal cells. AM stromal cells were able to promote the further differentiation of isolated brachyury -GFP + mesodermal cells into hematopoietic progenitors, whereas the OP9 stromal cells could not support the differentiation of these cells. Co-culture and analyses of individual embryoid bodies support the hypothesis that the AM stromal cell lines could enhance the de novo production of hematopoietic progenitors, lending support to the idea that AM stromal cells might act on prehematopoietic mesoderm. The induction level observed for AM stromal cells was comparable to HOXB4 activation, but no additive effect was observed when these 2 inductive strategies were combined. Addition of a γ-secretase inhibitor reduced the inductive effects of both the stromal cell line and HOXB4, providing clues to possible shared molecular mechanisms.

Serum- and Stromal Cell-Free Hypoxic Generation of Embryonic Stem Cell-Derived Hematopoietic Cells In Vitro, Capable of Multilineage Repopulation of Immunocompetent Mice

“…However, our observations that ectopically expressed HOXB4 can support the development of ESC-derived HSPCs capable of engrafting immunodeficient Rag2 (Ϫ/Ϫ) ␥C (Ϫ/Ϫ) [23] and immunocompetent 129S6/SvEvTac mice long-term, without the need of any coculture with stromal cells, may support the idea of a BMP4 independence of HOXB4-expressing cells. In agreement with this, others have also observed that coculture of HOXB4-expressing ESCs with AGM-derived stromal cells also did not further enhance their hematopoietic differentiation [41]. A recently published observation by Jackson et al may explain the nonadditive effect of stromal cocultures on hematopoietic differentiation of HOXB4 ϩ -ESCs [42].…”

Notch signaling partly regulates the osteogenic differentiation of retinoic acid-treated murine induced pluripotent stem cells

“…The products were electrophoresed in a 1.8% agarose gel and stained with ethidium bromide. The primer sequences are shown in Table 1 (4,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) Statistical analysis Data are shown as mean ± standard deviation. Statistical analysis was performed using the two-independent samples t-test for two-group comparisons and one-way …”

HOXB4 knockdown reverses multidrug resistance of human myelogenous leukemia K562/ADM cells by downregulating P-gp, MRP1 and BCRP expression via PI3K/Akt signaling pathway

“…The aberrant expression of HOXB4 is often related to poor prognoses of leukemia (23), mesothelioma (24) and ovarian cancer (25). Overexpression of HOXB4 is considered as a catalyst for the development of leukemia and influences the leukemia phenotype (26). Furthermore, Lehne et al (27) discovered that HOXB4 played an important role in chemoresistance of CML.…”