Effects of extracellular matrix proteins on the growth of haematopoietic progenitor cells

Abstract

Umbilical cord blood (UCB) transplantation and haematological recovery are currently limited by the amount of haematopoietic progenitor cells (HPCs) present in each unit. HPCs and haematopoietic stem cells (HSCs) normally interact with cells and extracellular matrix (ECM) proteins present within the endosteal and vascular niches. Hence, we investigated whether coating of culture surfaces with ECM proteins normally present in the marrow microenvironment could benefit the ex vivo expansion of HPCs. Towards this, collagen types I and IV (COL I and IV), laminin (LN) and fibronectin (FN) were tested individually or as component of two ECM-mix complexes. Individually, ECM proteins had both common and unique properties on the growth and differentiation of UCB CD34+ cells; some ECM proteins favoured the differentiation of some lineages over that of others (e.g. FN for erythroids), some the expansion of HPCs (e.g. LN and megakaryocyte (MK) progenitor) while others had less effects. Next, two ECM-mix complexes were tested; the first one contained all four ECM proteins (4ECMp), while the second 'basement membrane-like structure' was without COL I (3ECMp). Removal of COL I led to strong reductions in cell growth and HPCs expansion. Interestingly, the 4ECMp-mix complex reproducibly increased CD34+ (1.3-fold) and CD41+ (1.2-fold) cell expansions at day 6 (P < 0.05) versus control, and induced greater myeloid progenitor expansion (P < 0.05) than 3ECMp. In conclusion, these results suggest that optimization of BM ECM protein complexes could provide a better environment for the ex vivo expansion of haematopoietic progenitors than individual ECM protein.

Megakaryocytes Contribute to the Bone Marrow-Matrix Environment by Expressing Fibronectin, Type IV Collagen, and Laminin

“…These data are in line with the necessity of mature Mks to extend long cytoplasmatic processes, called proplatelets, through the fenestrations of the endothelial cell layer and into the vascular space, where platelets are shed into the circulation . Moreover, we mapped the localization of different collagens and glycoproteins that have been shown to be involved in the regulation of Mk differentiation or function in vitro . These results confirm and extend previous analysis of the ECM component composition of mouse BM by demonstrating that, in the BM, Mks are surrounded by large fibrils that stain positive for FNC, and the basement membrane components type IV collagen and laminin.…”

Distinct Stromal Cell Factor Combinations Can Separately Control Hematopoietic Stem Cell Survival, Proliferation, and Self-Renewal

“…Recent studies have highlighted a differential expression on the surface of HSCs and their closely related downstream derivatives of several integrins, which are receptors for such proteins (Benveniste et al., 2010, Notta et al., 2011, Wagers and Weissman, 2006). Thus, factors that activate these receptors may constitute an additional strategy for enhancing HSC expansion, as suggested by others (Celebi et al., 2011, Kurth et al., 2011, Umemoto et al., 2012). The ability of a combination of defined soluble proteins to promote HSC expansion in vitro refutes the hypothesis that cell contact is required to mediate such responses and should facilitate future interrogation of the mechanisms involved in the maintenance of the DSR state when HSCs are stimulated to proliferate.…”

Advances in umbilical cord blood stem cell expansion and clinical translation

“…This discovery led to the development of a considerable number of coculture systems for the expansion of HSPCs with various sources of feeder cells including BM-derived stromal cells [37,38], immortalized stromal cells [39][40][41] and endothelial cells [42][43][44][45][46] and bone marrow mesenchymal stem cells (MSC) [47][48][49][50][51][52][53]. Examples of such system are presented in Table 1 along with their principal properties and results.…”