Cell-substrate interaction

External information Cell response Soluble signaling molecules Differentiation Cell-cell interactions 1 1 Ptoliferation Cell-substrate interactions Quiescence Apogens Apoptosis NECROSIS /> 1 1 // -/ V ... 

CR3, LFA-1 and pl50,95 are a family of leukocyte proteins with distinct a-subunits but a common /J-subunit (Fig. 3.6). They are involved in cell-cell contact as well as in cell-substrate interactions. They thus function in a variety of adhesive processes. 

Drumheller SD, Hubbell JA (1995) Surface immobilization of adhesion ligands for investigations of cell substrate interactions. In Bronzino JD (ed) The biomedical engineering handbook. CRC Press, Boca Raton, FI, p 1584... 

Russo, R. (1986). Cell-substrate interactions in relation to metastasis. In Chadwick, C. M. (ed.). Receptors in Tumor Biology. Cambridge University Press, Cambridge, UK, pp. 131-168. 

Keywords QCM Cell-substrate interactions Cell adhesion Cell spreading Extracellular matrix Cellular micromechanics Cytoskeleton Cell elasticity ... 

Thus, two main conclusions can be drawn from these experiments (i) The QCM does only report on cells that are specifically anchored to the resonator surface. The method is blind to cells that just settle to the surface and attach only loosely, (ii) When specific cell-substrate interactions are omitted, the cells stay away from the surface by more than 100 nm, according to our RICM data. Theoretical considerations have previously indicated that cells may approach the surface as closely as 5-10 nm just by non-specific attraction [21]. This is, however, not confirmed by our optical measurements. 

Unfortunately the answer is, not very much. These studies do indeed show that the QCM approach is a very sensitive tool for studying any perturbation of cell-substrate interactions in real time and with a highly quantitative readout. But the system itself is too comphcated and holds too many variables to draw significant conclusions on the number of binding sites between cell and surface just from measurements of attachment and spreading in the presence of specific inhibitors. The enormous complexity arises from phenomena like ... 

Finally, the QCM can not only be used in a sensory mode but also as an actuator. It has been recently shown by Dultsev and coworkers [57] that virus particles deposited on the resonator surface may be displaced by increasing the shear amplitude of the resonator. Thus, it seems plausible that the resistance of cell-substrate interactions to lateral shear forces may be inferred from QCM measurements when the shear amplitude is increased to invasive magnitudes. The ease of the measurement, which can be automated and multiplexed, the rather simple experimental design, as well as the unique experimental access to the interface between living cells and technical substrates is very likely to create growing interest within the cell culture community for these new experimental options. 

Proteins generally adsorb onto solid surfaces from solution. This process is of importance in a number of applications. For instance, the composition, conformation, and orientation of adsorbed proteins are believed to influence cell/substrate interactions (1-3). Also, adsorption of serum proteins onto biomaterials is generally recognized as the initial event in the sequence that culminates in thrombus formation (4,5). Consequently, protein behavior at solid-liquid interfaces has been extensively studied (6-11). Many fundamental questions about the protein adsorption phenomenon, however, remain unanswered (12). 

It is possible to detect small differences in cell-substrate interactions using weak electric fields and in this manner to quantitatively measure differences in the dynamics of cell attachment and spreading to defined protein monolayers. The details of the system have been previously described (9-10). 

Figure 4b. Haptotactic behavior of WI-38 cells on a specially prepared glass coverslip. The background, showing normal cell-substrate interaction, is covered with a layer of adsorbed BSA, while the pattern (GEIOO) is covered with IgG molecules specifically attached to a base layer of BSA.

Fig. 4. Alterations in either ligand or material properties may alter the nature of cell-substrate interactions. These interactions, in turn, impact many aspects of cell function.

The ability of hydrophilic polymers, specifically PEG, to provide a substrate material that is essentially a blank slate is extremely valuable in both investigations of the nature of cell-substrate interactions as well as in the creation of well-defined biomaterials and tissue engineering scaflblds. In this marmer, PEG serves as an ideal material which can be modified to contain numerous biological signals. 

Schindl, M., WaUraff, E., Deubzer, B. et al. (1995). Cell-substrate interactions and locomotion of Dictyostelium wild-type and mutants defective in three cytoskeletal proteins a study using quantitative reflection interference contrast microscopy. Biophys. ]. 68, 1177-1190. 

Advances in our understanding of cell-substrate interactions are essential for controlling cell behavior and tissue formation. The ability to culture different cell types in close proximity on a variety of patterned polymeric substrates presents new opportunities to study cell-cell interactions and understand cell behavior. This is important, since within tissues, unique microenvironments exist that are a result of cell-cell proximity, communication, and the production of extracellular factors. Thus, recreating the cellular microenvironment in vitro is critical to understanding tissue function and development. 

Wegener J, Janshoff A, and Steinem C (2001) The quartz crystal microbalance as a novel means to study cell-substrate interactions in situ. Cell Biochemistry and Biophysics 34 121-151. 

Fourth Generation Photoactivatable Substrates with Molecularly Defined Cell-Substrate Interactions... 

On the photoactivatable substrates discussed so far, the cells adhere to the photoirradiated regions via the interaction with proteins physically adsorbed onto the surface after photoirradiation. These proteins originally existed in the culture medium, but we are not able to specify which proteins mediate cell adhesion. This fact obscures the molecular level discussion of the signaling originated from the cell-substrate interactions. To tackle this issue, we have developed two new photoactivatable substrates, where the photoexposed surface presents molecularly controlled cell-adhesive ligand. 

Acheson A, Sunshine JL, Rutishauser U (1991) NCAM poly-sialic acid can regulate both cell-cell and cell-substrate interactions. J Cell Biol 114 143-153... 

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