Effect of Cyclic stretching on the gene expression in human spinal ligament cells

Ossification of the posterior longitudinal ligament (OPLL) of the spine is characterized by progressive ectopic bone formation in the spinal ligament. To identify the genes related to ectopic ossification of human spinal ligament affected by mechanical stress, analyses using cDNA microarray were carried out using cultured human spinal ligament cells that had been subjected to uniaxial cyclic stretching. cDNA microarrays revealed that ranges of distribution of both up- and down-regulated genes evoked by cyclic stretching were significantly wider in cells from than in non-OPLL cells. Keywords: mechanical-stress response Cells were cultured in deformable silicon chamber which were exposed to cyclic stretching (120% extension ratio) for up to 9 hr. After cyclic stretching, total RNA was extracted from each cell monolayer. Target cDNAs transcribed from non-stretched control cells and stretched cells were labeled with Cy3 and Cy5, respectively, and then hybridized with an Agilent Human 1 cDNA Microarray. The microarrays were scanned in both the Cy3 and Cy5 channels with an Affymetrix 428 Array Scanner, and then analyzed using the ImaGene and GeneSight-Lite Software packages.