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The mechanism of oxythiamine-induced collagen biosynthesis in cultured fibroblasts.

Szoka L, Karna E, Palka J - Mol. Cell. Biochem. (2015)

Bottom Line: It was found that OXY-dependent increase in collagen biosynthesis was accompanied by parallel increase in prolidase activity and level, compared to untreated cells.The exposure of the cells to OXY contributed to decrease in IGF-IR, α2β1 integrin receptor, pERK1/2, and NF-κB p65 expressions.The data suggest that OXY-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of prolidase activity and level, induction in pAkt expression and down-regulation of pERK1/2 and NF-κB p65, the known inhibitor of collagen gene expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2 D, 15-222, Bialystok, Poland.

ABSTRACT
The oxythiamine (OXY) is antivitamin of thiamine. The finding that OXY increases the cytoplasmic concentration of pyruvate, known to enhance collagen biosynthesis, led us to investigate the mechanism of this antivitamin action on collagen biosynthesis in cultured human skin fibroblasts. Confluent fibroblasts were treated with micromolar concentrations (30-1,000 µM) of OXY for 24 and 48 h. It was found that OXY-dependent increase in collagen biosynthesis was accompanied by parallel increase in prolidase activity and level, compared to untreated cells. Since phosphoenolpyruvate (PEP) is known as an inhibitor of prolidase-the enzyme that plays important role in collagen biosynthesis, the mechanism of pyruvate interconversion was considered as a regulatory switch in collagen biosynthesis. In fact, 3-MPA, specific inhibitor of phosphoenolpyruvate carboxykinase (PEPCK), contributed to up-regulation of prolidase activity, suggesting that down-regulation of PEP formation is an underlying mechanism. Since collagen biosynthesis and prolidase activity are regulated by signal induced by activated α2β1 integrin receptor as well as insulin-like growth factor-I receptor (IGF-IR), the expression of these receptors was measured by Western immunoblot analysis. The exposure of the cells to OXY contributed to decrease in IGF-IR, α2β1 integrin receptor, pERK1/2, and NF-κB p65 expressions. It was accompanied by increase in total ERK1/2 expression and induction of phosphorylation of Akt protein. The data suggest that OXY-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of prolidase activity and level, induction in pAkt expression and down-regulation of pERK1/2 and NF-κB p65, the known inhibitor of collagen gene expression.

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Prolidase activity in confluent human skin fibroblasts incubated for 1 h (a), 6 h (b) and 24 h (c) in the medium containing 0.1 % FBS or 10 % FBS and 1 mM of 3-mercaptopicolinate (3-MPA), and different concentrations of OXY. The results present the mean values from 6 assays ± SD *P ≤ 0.01
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Fig3: Prolidase activity in confluent human skin fibroblasts incubated for 1 h (a), 6 h (b) and 24 h (c) in the medium containing 0.1 % FBS or 10 % FBS and 1 mM of 3-mercaptopicolinate (3-MPA), and different concentrations of OXY. The results present the mean values from 6 assays ± SD *P ≤ 0.01

Mentions: As can be seen in Fig. 3a and c, 1 and 24 h incubation of fibroblasts in the medium containing 0.1 % FBS and 1 mM OXY-induced prolidase activity, by about 40 and 30 %, respectively. However, 6 h incubation under the same conditions contributed to decrease in prolidase activity to 70 % of control (Fig. 3b). The mechanism of this phenomenon may involve PEP accumulation that inhibits prolidase activity and collagen biosynthesis.Fig. 3


The mechanism of oxythiamine-induced collagen biosynthesis in cultured fibroblasts.

Szoka L, Karna E, Palka J - Mol. Cell. Biochem. (2015)

Prolidase activity in confluent human skin fibroblasts incubated for 1 h (a), 6 h (b) and 24 h (c) in the medium containing 0.1 % FBS or 10 % FBS and 1 mM of 3-mercaptopicolinate (3-MPA), and different concentrations of OXY. The results present the mean values from 6 assays ± SD *P ≤ 0.01
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4383821&req=5

Fig3: Prolidase activity in confluent human skin fibroblasts incubated for 1 h (a), 6 h (b) and 24 h (c) in the medium containing 0.1 % FBS or 10 % FBS and 1 mM of 3-mercaptopicolinate (3-MPA), and different concentrations of OXY. The results present the mean values from 6 assays ± SD *P ≤ 0.01
Mentions: As can be seen in Fig. 3a and c, 1 and 24 h incubation of fibroblasts in the medium containing 0.1 % FBS and 1 mM OXY-induced prolidase activity, by about 40 and 30 %, respectively. However, 6 h incubation under the same conditions contributed to decrease in prolidase activity to 70 % of control (Fig. 3b). The mechanism of this phenomenon may involve PEP accumulation that inhibits prolidase activity and collagen biosynthesis.Fig. 3

Bottom Line: It was found that OXY-dependent increase in collagen biosynthesis was accompanied by parallel increase in prolidase activity and level, compared to untreated cells.The exposure of the cells to OXY contributed to decrease in IGF-IR, α2β1 integrin receptor, pERK1/2, and NF-κB p65 expressions.The data suggest that OXY-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of prolidase activity and level, induction in pAkt expression and down-regulation of pERK1/2 and NF-κB p65, the known inhibitor of collagen gene expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2 D, 15-222, Bialystok, Poland.

ABSTRACT
The oxythiamine (OXY) is antivitamin of thiamine. The finding that OXY increases the cytoplasmic concentration of pyruvate, known to enhance collagen biosynthesis, led us to investigate the mechanism of this antivitamin action on collagen biosynthesis in cultured human skin fibroblasts. Confluent fibroblasts were treated with micromolar concentrations (30-1,000 µM) of OXY for 24 and 48 h. It was found that OXY-dependent increase in collagen biosynthesis was accompanied by parallel increase in prolidase activity and level, compared to untreated cells. Since phosphoenolpyruvate (PEP) is known as an inhibitor of prolidase-the enzyme that plays important role in collagen biosynthesis, the mechanism of pyruvate interconversion was considered as a regulatory switch in collagen biosynthesis. In fact, 3-MPA, specific inhibitor of phosphoenolpyruvate carboxykinase (PEPCK), contributed to up-regulation of prolidase activity, suggesting that down-regulation of PEP formation is an underlying mechanism. Since collagen biosynthesis and prolidase activity are regulated by signal induced by activated α2β1 integrin receptor as well as insulin-like growth factor-I receptor (IGF-IR), the expression of these receptors was measured by Western immunoblot analysis. The exposure of the cells to OXY contributed to decrease in IGF-IR, α2β1 integrin receptor, pERK1/2, and NF-κB p65 expressions. It was accompanied by increase in total ERK1/2 expression and induction of phosphorylation of Akt protein. The data suggest that OXY-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of prolidase activity and level, induction in pAkt expression and down-regulation of pERK1/2 and NF-κB p65, the known inhibitor of collagen gene expression.

Show MeSH
Related in: MedlinePlus