Effects of substrate stiffness on functional responses to inflammatory cytokine in tenocytes

Abstract

The present study has investigated a relationship between cellular tension and functional responses to an inflammatory cytokine, interleukin-1b (IL-1b). Tenocytes from rabbit Achilles tendon were cultured on an array of PDMS-made micropillars with a 3 um diameter and 4 or 8 um heights, whereby cellular tension of tenocytes can be modulated depending on the stiffness of the micropillars. The cells were cultured on the micropillars with the presence of IL-1b at a concentration of 0, 1, 10 or 100 pM. The cells subjected to the same experiment on glass substrate were assigned to control samples. It was demonstrated that the IL-1b stimulation upregulated the gene expression of collagenase in tenocytes on micropillar substrates, and a higher expression was observed on the softer, 8 um micropillars compared to the 4 um micropillars. Cell morphology was also changed by the IL-1b administration, although the effects of cellular tension was not clearly exhibited.