title: Tenocytes, pro-inflammatory cytokines and leukocytes: a relationship?
abstract: Leukocyte derived pro-inflammatory mediators could be involved in tendon healing and scar formation. Hence, the effect of autologous leukocytes (PBMCs, peripheral blood mononuclear cells and neutrophils) on primary rabbit Achilles tenocytes gene expression was tested in insert assisted co-cultures. Subsequently, tenocytes gene expression of extra-cellular matrix (ECM) components (type I collagen, decorin, fibronectin), the cell-ECM receptor β1-integrin, the angiogenic factor myodulin, ECM degrading matrix-metalloproteinase (MMP)1 and pro-inflammatory cytokines (interleukin [IL]-1β, tumour necrosis factor [TNFα] and IL-6) was analysed. The only significant effect of leukocytes on tenocytes ECM genes expression was a suppression of type I collagen by neutrophils combined with TNFα stimulation. The same effect could be observed analysing the β1-integrin and myodulin gene expression. However, PBMCs up-regulated significantly cytokine and MMP1 gene expression in tenocytes. These in vitro results suggest that mononuclear cells could present an exogenic stimulus for the induction of pro-inflammatory and catabolic mediators in tendon.
authors.affiliation: Department for Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Onays
authors.initials: O
authors.lastname: Al-Sadi
authors.forename: Gundula
authors.initials: G
authors.lastname: Schulze-Tanzil
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kohl
authors.forename: Anke
authors.initials: A
authors.lastname: Lohan
authors.forename: Marion
authors.initials: M
authors.lastname: Lemke
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ertel
authors.forename: Thilo
authors.initials: T
authors.lastname: John
keywords: IL-1β; TNFα; cytokines; leukocytes; myodulin; tendon