Differential response of articular cartilage from young growing and mature old mice to IL-1 and TGF-beta

Osteoarthritic lesions are observed in temporomandibular joint cartilage of ICR mice aged 7 months and older, accompanied by reduced proliferation and matrix synthesis. Transforming growth factor-beta (TGF-beta), is a multifactorial growth factor affecting matrix synthesis and cell proliferation in bone and cartilage, whereas interleukin-1 (IL-1) is involved in cartilage degradation. In order to establish the repair capacity of cartilage in aging, the response of cartilage from young and old animals to TGF-beta and IL-1 was studied. Mandibular condyles from young (1-month-old) and old (18-month-old) mice were cultured for up to 72 h in medium supplemented with TGF-beta 1 or IL-1 alpha. TGF-beta increased protein (+9.26%) and DNA (+36.0%) contents in young animals and DNA content (+19.49%) in old animals. Incorporations of [H-3]thymidine and [S-35]sulfate were enhanced in young (+254% and +116% respectively) and in old (+22.6% and +6.88%, respectively) animals and activity of alkaline phosphatase was induced in old animals. Treatment with IL-I resulted in reduced DNA content in young (-35.76%) and old (-33.33%) animals, but acid phosphatase activity was induced in old animals. It is concluded that TGF-beta can induce anabolic activity even in cartilage from old animals indicating repair response in articular cartilage in aging. Copyright (C) 1997 Elsevier Science Ireland Ltd.