Geometric cues for directing the differentiation of mesenchymal stem cells

Abstract

Significant efforts have been directed to understanding the factors that influence the lineage commitment of stem cells. This paper demonstrates that cell shape, independent of soluble factors, has a strong influence on the differentiation of human mesenchymal stem cells (MSCs) from bone marrow. When exposed to competing soluble differentiation signals, cells cultured in rectangles with increasing aspect ratio and in shapes with pentagonal symmetry but with different subcellular curvature-and with each occupying the same area-display different adipogenesis and osteogenesis profiles. The results reveal that geometric features that increase actomyosin contractility promote osteogenesis and are consistent with in vivo characteristics of the microenvironment of the differentiated cells. Cytoskeletal-disrupting pharmacological agents modulate shape-based trends in lineage commitment verifying the critical role of focal adhesion and myosin-generated contractility during differentiation. Microarray analysis and pathway inhibition studies suggest that contractile cells promote osteogenesis by enhancing c-Jun N-terminal kinase (JNK) and extracellular related kinase (ERK1/2) activation in conjunction with elevated winglesstype (Wnt) signaling. Taken together, this work points to the role that geometric shape cues can play in orchestrating the mechanochemical signals and paracrine/autocrine factors that can direct MSCs to appropriate fates. were initially isolated from bone marrow and noted for their ability to differentiate into bone cells (osteoblasts), cartilage cells (chondrocytes), and fat cells (adipocytes) (1, 2). As an autologous source of stem cells, MSCs are under considerable scrutiny for regenerative therapies (3). A combination of physical, chemical, and biological cues present in the stem cell microenvironment have been implicated as directors of stem cell fate in vivo (4). This concept of a stem cell "niche" has motivated empirical studies to identify optimal combinations of extracellular matrix, culture conditions, and temporally administered growth factors to direct stem cell fate in the laboratory (5-7). However, the physical forces and geometry of the MSC microenvironment remain poorly defined and have begun to emerge as critical parameters for regulating cell fate (8, 9).Physical cues, which were postulated as important factors in tissue development over a century ago (10), have also been recognized as important factors in controlling cell function. Research along these lines has been driven in the past decades with the maturation of microengineering techniques (11-13). Ingber, Whitesides, and colleagues demonstrated the use of substrates that were geometrically patterned to control the microenvironment of individual cells and in turn the decision of cells to initiate apoptosis (14). Patterned substrates have also been used to study cytoskeletal dynamics (15-18) and motility (19-22) with singlecell resolution. Chen and coworkers recently demonstrated the important role that cell shape and size can play ...

The simulated microgravity enhances multipotential differentiation capacity of bone marrow mesenchymal stem cells

“…We demonstrated that the morphology of BMSCs was changed under the SMG condition and thus had larger capability to differentiate to other cell types. This result further demonstrated that there was some interplay between the geometric cues of the cells and their functions (Kilian et al 2010). While previous report illustrated that SMG was helpful to expand stem cell populations in vitro (Yuge et al 2006), our work further demonstrated that SMG enabled cells to maintain pluripotency and therefore enhance multipotential differentiation capacity.…”

“…Geometric shape cues have shown to have great effect on the differentiation of human BMSCs (Kilian et al 2010). McBeath and his coworkers recently confirmed that cell shape and size had a large effect on the fate of MSCs (McBeath et al 2004).…”

Surface Curvature Differentially Regulates Stem Cell Migration and Differentiation via Altered Attachment Morphology and Nuclear Deformation

“…In previous studies, 2D adhesive patterns of different sizes, shapes or aspect ratios have been used to demonstrate how stem cell differentiation is influenced by the shape of either individual cells or multicellular structures 10, 14, 22. The results presented here show that 3D substrate geometries of equal size and shape but of opposite curvature (convex vs concave) can also have a significant influence of osteogenic marker expression.…”

“…Numerous studies have shown that the mechanical properties of the cell's microenvironment, such as the substrate stiffness, have a fundamental effect on hMSC cell fate and function and impact tissue regeneration 6, 7, 8, 9. Recently, evidence is rising that the geometrical properties of the cell's environment also play an important role as regulators of cell behavior 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. Using geometric features, such as pore geometry, as a cue to direct tissue regeneration is compelling since it may allow a biomaterial to steer cell function purely by its shape and hereby contribute to tissue regeneration.…”

Tunable Pentapeptide Self‐Assembled β‐Sheet Hydrogels

“…These three different peptide designs demonstrate that alteration of the position of the β‐sheet‐forming amino acids and charge distribution of the sequence serves as a unique approach to control the morphology and tune the mechanical properties of the resultant hydrogel. Both substrate stiffness and substrate shape have been shown to influence cellular behavior 29, 30, 42. Therefore, with control over both of these parameters, the hydrogels have potential to act as tissue‐engineering scaffolds and matrices.…”