CelluCCCClar changes in human tendon cells as a result to release of mechanical tension

Abstract

The objective was to study the effect of tension release on human tendon cell gene expression and cell‐matrix interaction. Tendon cells in healthy tendon are subjected to tensile load, but in injured tendon, this stimulus is disrupted. This might lead to substantial cellular changes and alterations in cell‐matrix interactions, thereby complicating healing. Differentiated tendon cells express scleraxis, tenomodulin (Tnm), Mohawk homeobox (Mkx) and several matrix proteins, and tendon cells bind to the matrix through integrins. We hypothesized that tension release will lead to a downregulation of tendon‐specific genes and a decline of proteins by which cells interact with the matrix. Tendon‐like tissue was engineered with human tendon cells and cultured under static load or in the absence of load. Samples were collected 6 days post tension release and analyzed for gene and protein expression. Release of tension reduced gene expression of Tnm, Mkx, collagen type I, III, XII and XIV and decorin (p< 0.05) and preliminary results show decreased protein levels of the collagen receptor integrin α11. The study emphasizes the importance of tensile load on cell differentiation and formation of cell‐matrix contacts. The de‐coupling of cell‐matrix interactions might be a crucial factor in tissue injury and regeneration.Research was supported by the Danish Medical Research Council, the Nordea Foundation and Lundbeck foundation.