Hematopoietic stem and progenitor cells in adhesive microcavities

Abstract

The homeostasis of hematopoietic stem and progenitor cells (HSC) in the bone marrow is regulated by a complex interplay of exogenous signals, including extracellular matrix (ECM) molecules, cell-cell contacts, and cytokines. To investigate the influence of spatial restriction and adhesive interactions on HSC fate decisions, we prepared a set of fibronectin-coated micrometer-sized cavities. Analysis of human CD133+ HSCs isolated after culture on these surfaces revealed that proliferation and differentiation is decreased when HSCs are supported by substrates with small microcavities. Single cell analysis of adherent cells also revealed decreased DNA synthesis and higher levels of HSC marker expression inside the smaller cavities. Increasing the cytokine concentration highlighted the tight balance of adhesion related signals and soluble cues acting on HSC fate decisions. Our results suggest that confining human HSCs in ECM-coated microcavities is a possible method to maintain these cells in a quiescent and immature state, an important advantage for several HSC applications.

Stem cells in microfluidics

“…Many processing tools for HSCs are introduced and reviewed in this section including purification and separation, 145,[154][155][156][157][158] signaling analysis, [159][160][161][162][163][164] microchip electrophoresis assays, and microfluidicbased, digital, reverse transcription-polymerase chain reaction ͑RT-PCR͒ assays. [165][166][167] …”

Artificial Hematopoietic Stem Cell Niches-Dimensionality Matters

“…They identified two parameters that each showed a significant association with clones containing HSCs after 4 days of culture: a prolonged cell-cycle time measured over three divisions and a reduced proportion of progeny with uropodia at any time between 84 and 96 h of culture [76]. In an attempt to dissect the impact of geometrical constraints and adhesive interactions on HSCs during cytokine-driven expansion, Kurth et al [77,78] used CD133 + -cells that were cultivated in micrometer-scale cavities with 10 µm in depth and 15 to 80 µm in diameter, manufactured from PDMS and coated with fibronectin or collagen I. In this model it was shown that HSCs residing in smaller cavities displayed a decreased proliferation and differentiation accompanied by decreased DNA synthesis and an increased HSC marker expression [77].…”

“…In an attempt to dissect the impact of geometrical constraints and adhesive interactions on HSCs during cytokine-driven expansion, Kurth et al [77,78] used CD133 + -cells that were cultivated in micrometer-scale cavities with 10 µm in depth and 15 to 80 µm in diameter, manufactured from PDMS and coated with fibronectin or collagen I. In this model it was shown that HSCs residing in smaller cavities displayed a decreased proliferation and differentiation accompanied by decreased DNA synthesis and an increased HSC marker expression [77]. Similar results have been shown with another system described as a single cell-system, although the characteristics of the system are also suited to be mentioned under 3D-systems.…”

The haematopoietic stem cell niche at a glance

“…Although it is still impossible to test how contact area, shape and matrix stiffness impact HSC fate in vivo, it could be shown that HSCs seeded on microwells actively produce their own ECM and undergo quiescence or proliferation depending on the size of the well (Kurth et al, 2009). In addition, SPP1 was the first osteoblast-derived ECM protein that was shown to influence HSC number and function (Nilsson et al, 2005;Stier et al, 2005).…”