The effect of glucose deprivation on collagen synthesis in fibroblast cultures Marzanna Cechowska-Pasko Æ Arkadiusz Sura _ zyn ´ski Æ Edward Ban ´ kowski Received: 4 December 2008 / Accepted: 4 February 2009 / Published online: 19 February 2009 Ó Springer Science+Business Media, LLC. 2009 Abstract It was decided to study the effect of glucose deprivation on collagen synthesis and degradation in fibro- blast 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 pro- teins was used as an index of collagen synthesis, whereas pulse-chase technique was employed to evaluate the degra- dation 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 med- ium 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. Keywords Glucose deprivation Á Collagen synthesis Á Collagen degradation Á Oxygen regulated protein 150 Á Fibroblasts Introduction It was described in our previous paper that glucose depri- vation resulted in a marked decrease of collagen content in fibroblast cultures [1]. This phenomenon may be evoked by a decrease of collagen biosynthesis, increased degradation of this protein or by coexistence of both phenomena. Obviously collagen biosynthesis requires energy supply. Glucose is the main energetic substrate and glycolysis is the main process which supplies energy for fibroblasts grown in vitro [2]. For these reasons, the glucose shortage may reduce intracellular pool of ATP required for the functions of these cells including collagen biosynthesis. Furthermore, the shortage of glucose in culture medium enhances proteolytic (and gelatinolytic) activity in these cells [3, 4] and may promote collagen degradation. On the other hand glucose deprivation appeared to be a factor which induces the expression of oxygen-regulated protein (ORP) 150 in fibroblasts cultures [1]. Oxygen- regulated protein of molecular weight 150 kDa (ORP150) and glucose-regulated protein of molecular weight 170 (GRP170) are ER—chaperones, which facilitate protein folding [5]. The GRP170 is a glycosylated form of ORP150. The ORP150/GRP170 system is a part of the ER machinery that assists in the folding and assembly of M. Cechowska-Pasko (&) Department of Pharmaceutical Biochemistry, Medical University of Bialystok, Mickiewicza 2A, 15-089 Bialystok, Poland e-mail: mapasko@tlen.pl A. Sura _ zyn ´ski Department of Medicinal Chemistry, Medical University of Bialystok, Bialystok, Poland E. Ban ´kowski Department of Medical Biochemistry, Medical University of Bialystok, Bialystok, Poland 123 Mol Cell Biochem (2009) 327:211–218 DOI 10.1007/s11010-009-0059-8