The effect of glucose deprivation on collagen synthesis in fibroblast cultures.

It was decided to study the effect of glucose deprivation on collagen synthesis and degradation in fibroblast cultures and a correlation of these processes with the expression of oxygen/glucose regulated proteins (ORP150/GRP170). The incorporation of radiolabeled proline into collagenase-sensitive and hydroxyproline-containing proteins was used as an index of collagen synthesis, whereas pulse-chase technique was employed to evaluate the degradation of newly synthesised proteins. We demonstrated that fibroblasts incubated in high-glucose medium synthesised detectable amounts of collagenous proteins. Most of them were secreted into the culture medium. The shortage of glucose resulted in about 30% reduction in synthesis of collagenous proteins, both those secreted into culture medium and remaining in the cell layer. The pulse-chase experiments demonstrated that the reduced amount of newly synthesised collagen was protected against intracellular degradation. Proportionally less collagen was degraded in cultures incubated in low-glucose than in high-glucose media. These phenomena were accompanied by an increase in the expression of chaperon-ORP150 in cultures growing in low-glucose medium. We suggest that the increased expression of ORP150 is a factor which protects collagen against intracellular degradation induced by glucose deprivation.