Aim: To determine the pattern of gene expression induced in cultured human chondrocytes in response to compressive mechanical loads.

Methods: Chondrocytes were obtained from tissue discarded at the time of a number of total knee replacements and where established in primary cell culture. The cultured chondrocytes were then subjected to compressive and tensile loads using a Flexcell machine. The RNA was subsequently extracted from these chondrocytes and the alterations in gene expression determined using the Affymetrix Gene Array machine.

Results: Intended as an in vitro model for Osteoarthritis, it was found that mechanical stimulation of human chondrocytes caused a significant alteration in the expression of a number of classes of compounds. These included enzymes, inflammatory mediators and structural proteins.

Conclusions: This study identified several interesting candidate genes whose expression was significantly altered after being exposed to a laboratory model for osteoarthrosis. Further study of these genes and their expression may lead to important clinical applications.