Compliant substratum modulates vinculin expression in focal adhesion plaques in skeletal cells

Abstract

The biophysical properties of the extracellular matrix (ECM) dictate tissue-specific cell behaviour. In the skeleton system, bone shows the potential to adapt its architecture and contexture to environmental rigidity via the bone remodelling process, which involves chondrocytes, osteoblasts, osteoclasts, osteocytes and even peripheral bone marrow-derived stem/stromal cells (BMSCs). In the current study, we generated stiff (~1 014 ± 56) kPa, Young’s modulus) and soft (~46 ± 11) kPa silicon-based elastomer polydimethylsiloxane (PDMS) substrates by mixing curing agent into oligomeric base at 1:5 and 1:45 ratios, respectively, and investigated the influence of substrate stiffness on the cell behaviours by characterizing cell spreading area, cell cytoskeleton and cell adhesion capacity. The results showed that the cell spreading areas of chondrocytes, osteoblasts, osteoclasts, osteocytes and BMSCs were all reduced in the soft substrate relative to those in the stiff substrate. F-actin staining confirmed that the cytoskeleton was also changed in the soft group compared to that in the stiff group. Vinculin in focal adhesion plaques was significantly decreased in response to soft substrate compared to stiff substrate. This study establishes the potential correlation between microenvironmental mechanics and the skeletal system, and the results regarding changes in cell spreading area, cytoskeleton and cell adhesion further indicate the important role of biomechanics in the cell-matrix interaction.

Cytocompatibility of Graphene Monolayer and Its Impact on Focal Cell Adhesion, Mitochondrial Morphology and Activity in BALB/3T3 Fibroblasts

“…Our results presented actin cytoskeleton staining and showed longitudinal filaments along the long axis of the BALB/3T3 cells with colocalization of vinculin on the cell edges. Vinculin is an important FA protein, characteristic for nascent cell-matrix adhesion and mature FA, which bound integrins to cytoplasmic F-actin [ 31 ]. Disruption of the vinculin-F-actin interaction affects cell motility, cell stiffness and adhesion [ 32 ].…”

“…Disruption of the vinculin-F-actin interaction affects cell motility, cell stiffness and adhesion [ 32 ]. Zhou et al [ 31 ] revealed that vinculin in focal adhesion plaques was significantly decreased in response to soft substrate compared to stiff substrate and cell spreading areas of chondrocytes, osteoblasts, osteoclasts, osteocytes and bone marrow-derived stem cells were also reduced in the soft substrate. Kim and Wirts [ 33 ] characterized parameters of FA of mouse embryonic fibroblasts—MEFs and found that FA display an ellipsoidal shape and FA area was approximately 3 μm 2 for glass substrate and decreased with the decreasing of substrate stiffness, reaching about 1.5 μm 2 on soft gel.…”

Transforming growth factor-β1-induced N-cadherin drives cell–cell communication through connexin43 in osteoblast lineage

“…Immunofluorescence staining was performed as previously described. 42 , 43 Briefly, Cells were cultured in Petri dishes specified for confocal laser microscopy for 12 h (1 000 cells per dish, Glass Bottom Cell Culture Dish, Φ15 mm, No. 801002, NEST, Jiangsu, China).…”

The role of TGF-β2 in cartilage development and diseases

“… 84 , 85 Based on structural differences, growth plate cartilage has four zones, which are the resting zone, proliferative zone, pre-hypertrophic zone, and hypertrophic zone, and most of the terminally differentiated chondrocytes undergo apoptosis, leaving ECM that is good for the invasion of osteoblasts and blood vessels ( Figure 3 ). 86 , 87 Eventually, osteoblasts secrete bone matrix to replace cartilage matrix and realize ossification. TGF-β2 expresses in all zones during cartilage development, but mainly exists in the ECM of hypertrophy zone.…”