The fate of stem cells can be affected by the stiffness of their past environments, reports a paper published online in Nature Materials.
Previous studies have shown that mechanical cues from the current local environment of the stem cells - such as the stiffness of the gel they are cultured on - can direct how they will differentiate. Kristi Anseth and colleagues found that the culture history of human mesenchymal stem cells, in particular the amount of time that the cells had been cultured on gels with different stiffness, also influenced the cells’ future fate decisions. This ‘mechanical memory’ effect, the authors report, is mediated by the transcriptional co-activators YAP and TAZ. The researchers harnessed this ability of stem cells to retain information from past environments to induce them to differentiate largely into bone cells on substrates where they would naturally become mostly fat cells.