Cellular mechanical properties reflect the differentiation potential of adipose-derived mesenchymal stem cells

Abstract

The mechanical properties of adipose-derived stem cell (ASC) clones correlate with their ability to produce tissue-specific metabolites, a finding that has dramatic implications for cell-based regenerative therapies. Autologous ASCs are an attractive cell source due to their immunogenicity and multipotent characteristics. However, for practical applications ASCs must first be purified from other cell types, a critical step which has proven difficult using surface-marker approaches. Alternative enrichment strategies identifying broad categories of tissue-specific cells are necessary for translational applications. One possibility developed in our lab uses single-cell mechanical properties as predictive biomarkers of ASC clonal differentiation capability. Elastic and viscoelastic properties of undifferentiated ASCs were tested via atomic force microscopy and correlated with lineage-specific metabolite production. Cell sorting simulations based on these "mechanical biomarkers" indicated they were predictive of differentiation capability and could be used to enrich for tissue-specific cells, which if implemented could dramatically improve the quality of regenerated tissues.cell mechanics | mesenchymal stem cell enrichment | viscoelasticity | single-cell characterization | AFM A dipose tissue contains a heterogeneous population of mesenchymal stem cells (MSCs) known as adipose-derived stem cells (ASCs) (1). ASCs are capable of differentiating into a variety of lineage-specific cell types, including adipocytes, osteoblasts, and chondrocytes (1-3). In comparison to MSCs derived from other tissues, ASCs are simple to isolate and available in large quantities (4, 5). Because of the cells' mesodermal origin, ASCs have been used for many soft tissue and orthopaedic applications (6-10). Unfortunately, ASC isolation is confounded by the lack of distinct and universally effective MSC biomarkers. Adipose tissue contains multiple cell types, including mature adipocytes, fibroblasts, smooth muscle cells, and endothelial cells (11), which can contaminate the stromal fraction collected during ASC isolation. While conventional methods such as flow cytometry can isolate stem cells using surface antigen expression (1, 2, 12), resulting cell yields are often less than 1% (13,14). Furthermore, the surface antigens present on ASCs can also be found on other cell types in adipose tissue, complicating the isolation of pure mesenchymal stem cell populations (15-17). Collectively, these limitations suggest a need for alternative biomarkers that allow for ASC enrichment based on lineage potential.Recently, single-cell mechanical properties were found to be akin to gene and protein expressions, capable of distinguishing differences in cellular subpopulations, disease state, and tissue source (18)(19)(20)(21)(22). Cells display varying levels of resistance to deformation (elasticity) and flow (viscosity) in response to an applied force. This behavior depends on the composition and organization of subcellular structures, particularly the cytosk...

Deformability of Human Mesenchymal Stem Cells Is Dependent on Vimentin Intermediate Filaments

“…Response to mechanical stresses is 9 partially governed by cellular mechanical properties. Changes in MSC mechanical 10 properties have been found to be related to both their physical environment and 11 differentiation potential 10,19,20,37 . Mechanical properties and mechanotransduction are in 12 part regulated by the cytoskeleton, consisting primarily of actin microfilaments, 13 microtubules, and vimentin intermediate filaments (IFs) for cells of mesenchymal 14 lineage 5,7,19,23,24,29,30,34,36 .…”

“…Oncogene expression-dependent collapse of the vimentin network 8 in fibroblasts caused an increase in cellular stiffness, which supports vimentin IFs 9 association with tumor invasion and tumor cell stiffness 26 . IF collapse caused by 10 mutated desmin revealed a complex distribution of cellular stiffness with increased 11 cellular stiffness in regions of the collapsed vimentin and a decrease in stiffness in the 12 remaining vimentin-deficient cytoplasm 25 . 13 …”

High-throughput physical phenotyping of cell differentiation

“…Recent findings have clearly demonstrated that physical and mechanical properties can be a promising alternative for phenotyping a range of cell types in different stages. For example, a recent study identified that the differentiation potential of mesenchymal stromal/stem cells is strongly dependent on their elastic and viscoelastic properties 5 . Similarly, it was shown that cell mechanical markers can be a promising alternative for predicting osteogenesis of differentiating stem cells 6 .…”

Investigation of cellular responses upon interaction with silver nanoparticles

“…12,17,18 Recent reports underscore the important role of AFM in biomedical studies including the mechanical properties of stem cells involved in lineage specification, 19,20 mechanics-based cancer diagnosis, 21 investigation of bacterial resistance to antibiotics, 22 detection of aging cartilage and osteoarthritis, 23 stem cell differentiation by matrix elasticity, 24 molecular-molecular interaction, 25 and protein-cell adhesion. 26 Hence, the application of AFM to the study of interfaces has begun to reveal the interaction between cells and NPs at picoNewton (pN) sensitivity and high accuracy.…”