Heat shock induces the expression of pro-inflammatory cytokines in human Achilles tendon tenocytes.

The aim of our study is to investigate the behaviour of healthy and tendinopathic human tenocytes after a heat shock. After we harvested tendinopathic and healthy human tendon samples, we split tenocytes into 4 groups: 3 groups were submitted to heat shock, followed by different periods of post-heating (2, 4 and 20 h). The other group represents our negative control. The target genes were analysed using Real Time PCR. IL-1β and IL-6 expression were significantly increased in tendinopathic samples after heat shock. COL1 and COL3 expression were increased in non-stimulated tendinopathic tenocytes, but their levels significantly decreased after heat shock (p less than 0.01). COL3 levels increase in healthy samples after 20 h post-heating (p less than 0.01). COL1 and COL3 decreased after heat shock as a sign of the failure of repair mechanisms in tendinopathic tendons. Heat shock in in vitro models was insufficient to trigger pro-inflammatory cytokines in healthy human tenocytes.