Epigenetic reprogramming induces the expansion of cord blood stem cells
Pratima Chaurasia, David C. Gajzer, Christoph Schaniel, Sunita D’Souza, Ronald Hoffman
Pratima Chaurasia, David C. Gajzer, Christoph Schaniel, Sunita D’Souza, Ronald Hoffman
View: Text | PDF
Technical Advance

Epigenetic reprogramming induces the expansion of cord blood stem cells

Abstract

Cord blood (CB) cells that express CD34 have extensive hematopoietic capacity and rapidly divide ex vivo in the presence of cytokine combinations; however, many of these CB CD34+ cells lose their marrow-repopulating potential. To overcome this decline in function, we treated dividing CB CD34+ cells ex vivo with several histone deacetylase inhibitors (HDACIs). Treatment of CB CD34+ cells with the most active HDACI, valproic acid (VPA), following an initial 16-hour cytokine priming, increased the number of multipotent cells (CD34+CD90+) generated; however, the degree of expansion was substantially greater in the presence of both VPA and cytokines for a full 7 days. Treated CD34+ cells were characterized based on the upregulation of pluripotency genes, increased aldehyde dehydrogenase activity, and enhanced expression of CD90, c-Kit (CD117), integrin α6 (CD49f), and CXCR4 (CD184). Furthermore, siRNA-mediated inhibition of pluripotency gene expression reduced the generation of CD34+CD90+ cells by 89%. Compared with CB CD34+ cells, VPA-treated CD34+ cells produced a greater number of SCID-repopulating cells and established multilineage hematopoiesis in primary and secondary immune–deficient recipient mice. These data indicate that dividing CB CD34+ cells can be epigenetically reprogrammed by treatment with VPA so as to generate greater numbers of functional CB stem cells for use as transplantation grafts.

Authors

Pratima Chaurasia, David C. Gajzer, Christoph Schaniel, Sunita D’Souza, Ronald Hoffman

×

Figure 13

Comparison of the frequency of SRCs in PCs and the progeny of an equivalent number of CD34+ cells cultured under control conditions or treated with VPA.

Options: View larger image (or click on image) Download as PowerPoint
Comparison of the frequency of SRCs in PCs and the progeny of an equival...
(A) Increasing numbers of PCs (50, 250, 500, 2,500, and 5,000) and the progeny of cultures initiated with an equivalent number of cells cultured under control conditions or in the presence of VPA were individually transplanted into NSG mice. Percentage of human CD45+ cell engraftment in the BM of recipient mice after 12 to 13 weeks is shown. (B) Poisson statistical analysis was performed using the number of mice with or without evidence of human cell engraftment (Table 4). Graph represents the percentage of mice without human cell chimerism (negative) following the transplantation of PCs or the progeny of equivalent numbers of CD34+ cells from control cultures or cultures containing VPA. Dotted lines represent 95% CIs. (C) SRC numbers were calculated using Poisson statistical analysis and are represented as the number of SRCs per 1 × 106 CD34+ cells. **P ≤ 0.002; ANOVA, P = 0.003. n = 111 NSG recipient mice.