Intact tissue fibres are held under tension by the pulling force from cells in the fibrous network. When fibronectin fibres are stretched by forces, simulations of this process showed that the distances between the individual binding sites on fibronectin, as bridged by the bacterial peptide, grow too large and hence the bacterial nano-adhesive becomes largely detached.
At the time, the researchers had not expected such results. These suggested that the Staphylococcus aureus bacterium, whose adhesion was used in the simulation, might in the course of its evolution have developed a nano-sensor to detect the tensional state of fibronectin fibres. In order to ‘successfully’ infect a lesion, the dreaded bacterium probably binds itself to severed and therefore structurally relaxed fibres.
However, little is known about the tensional state of tissue fibres and their effect on physiological processes in degenerative changes in tissue, for example. There is also a lack of methods suitable for measuring the minuscule forces that cells exert on tissue fibres.
Viola Vogel and her research group are therefore working on nano-sensors that can do the job: inspired by the simulations, they developed a bacterial peptide able to recognise the tensional states of fibronectin in tissue. Such a peptide could be used both in therapy and diagnostics.
Predicted nano-sensors successfully tested
Now, tests on the synthetically produced peptide in cell cultures as well as in tumour tissue from animal models have given the researchers positive results. Because the peptide binds to un-tensioned fibres only, it can visibly reveal which tumour tissue fibres are under tension. The research findings were published today in the scientific journal Nature Communications (“Novel peptide probes to assess the tensional state of fibronectin fibers in cancer”).
