Expression of transduced HSP70 gene protects chondrocytes from stress

Objective. To investigate the efficacy of adenovirus vector mediated transduction of heat shock protein 70 (HSP70) gene to human chondrocyte-like cell (HCS-2/8) against heat stress. Methods. Two adenovirus vectors that contain wild-type (AxSHEwt) or mutant-type (AxSHEmt) HSP70 gene, and that are regulated by SRα promoter, were constructed. The mutant-type lacks the area that expresses stress durability. One of the 2 adenovirus vectors was added to the cultures of human chondrocyte-like cells (HCS-2/8). Heat stress (48°C) was applied to the transduced cells for 2 h, and the efficacy of adenovirus vector mediated transduction of HSP70 gene against heat stress in the chondrocytes was investigated using alamar blue assay and MTT assay. Results. Absorbance levels at 48°C were 300.3 ± 51.9 and 1.173 ± 0.011 in the controls, 278.5 ± 33.8 and 1.217 ± 0.018 in the AxSHEmt transduced cells, and 349 ± 14.7 and 1.371 ± 0.033 in the AxSHEwt transduced cells. The level in the AxSHEwt transduced cells was significantly higher than in the other 2 groups (p < 0.05). With 37°C treatment, no significant difference was observed. Conclusion. Chondrocytes to which HSP70 gene was transduced had a significantly higher metabolic activity and viability under heat stress.