Comparative Gene Expression Profiling of Stromal Cell Matrices that Support Expansion of Hematopoietic Stem/Progenitor CellsAbhilasha Tiwari1,2, Christophe Lefevre2, Mark A Kirkland2*, Kevin Nicholas2 and Gopal Pande1*
- *Corresponding Author:
- Gopal Pande
CSIR-Centre for Cellular and Molecular Biology
Uppal Road, Hyderabad 500007, India
Tel: +91 40 27192605
Fax: +91 40 27160581
- Mark A. Kirkland
Institute for Technology Research and Innovation
GTP, Deakin University, Geelong 3220, Australia
Tel: +61 3 5227 1102
Fax: +61 3 5227 1103
Received date: July 23, 2013; Accepted date: September 18, 2013; Published date: September 20, 2013
Citation: Tiwari A, Lefevre C, Kirkland MA, Nicholas K, Pande G (2013) Comparative Gene Expression Profiling of Stromal Cell Matrices that Support Expansion of Hematopoietic Stem/Progenitor Cells. J Stem Cell Res Ther 3:152. doi:10.4172/2157-7633.1000152
Copyright: © 2013 Tiwari A, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The bone marrow microenvironment maintains a stable balance between self-renewal and differentiation of hematopoietic stem/progenitor cells (HSPCs). This microenvironment, also termed the “hematopoietic niche”, is primarily composed of stromal cells and their extracellular matrices (ECM) that jointly regulate HSPC functions. Previously, we have demonstrated that umbilical cord blood derived HSPCs can be maintained and expanded on stromal cell derived cellular matrices that mimic the complexity of the hematopoietic niche. The results indicated that matrices prepared at 20% O2 with osteogenic medium (OGM) were best suited for expanding committed HSPCs, whereas, matrices prepared at 5% O2 without OGM were better for primitive progenitors. Based upon these results we proposed that individual constituents of these matrices could be responsible for regulation of specific HSPC functions. To explore this hypothesis, we have performed comparative transcriptome profiling of these matrix producing cells, which identified differential expression of both known niche regulators, such as Wnt4, Angpt2, Vcam and Cxcl12, as well as genes not previously associated with HSPC regulation, such as Depp. MetaCore analysis of the differentially expressed genes suggests the down-regulation of several ECM related pathways and up-regulation of Ang-Tie2 and Wnt signaling pathways in OGM under high O2 (20%). Our findings provide an overview of several known and unique genes and pathways that play potential key roles in the support of HSPCs by stromal cells, both ex vivo and in vivo, and could be helpful in understanding the complex network of signaling and communication in hematopoietic niches.