Final answer:
The niche affects stem cell differentiation through the mechanical and adhesive properties of the substrate, inducing cytoskeletal changes and gene expression that lead to specific cell types such as muscle cells.
Step-by-step explanation:
The niche is fundamental in controlling stem cell differentiation, affecting cellular response and development. The mechanical or adhesive properties of the substrate can influence the destiny of stem cells by directing their differentiation into muscle cells or other specialized types. Early-time development of nematic order in the cell’s cytoskeleton, specifically actomyosin bundles, on substrates of particular rigidities can be a precursor to differentiation. Moreover, this reflects on how physical signals could be potentially easier to control and possibly more durable than manipulating biochemical or genetic factors.
These physical signals impact the cell on different levels, from inducing cytoskeletal (CSK) changes to influencing cell shape and cellular mechanics. Optimal substrate rigidity promotes maximum polarization of the CSK and contractile forces, which might stimulate specific genetic expressions pertinent to the differentiated cell type, like muscle cells. Additionally, mechanical properties including the rigidity perceived by cells and the mechanics of ligand molecules themselves could also steer stem cell differentiation pathways.