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Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

Sroga GE, Siddula A, Vashishth D - PLoS ONE (2015)

Bottom Line: Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors.Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content.Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America.

ABSTRACT
To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs) at the levels that corresponded to approx. 25-30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation) or ribose (ribosylation). Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN) in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women). More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples). Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar supplementation in food and drinks.

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Related in: MedlinePlus

Examples of UPLC chromatograms.A. Identification of PEN (shown by red arrow) in the glucosylated human cortical bone samples. B. Identification of PEN (shown by red arrow) in the ribosylated human cortical bone samples. C. The UPLC chromatogram with the peak of ProOH (shown by red arrow) used for determination of collagen contents. Similar amounts of the samples were injected to the column. Notably, the chromatogram obtained from the analysis of the ribosylated sample contains several peaks that are not present in the glucosylated sample.
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pone.0117240.g002: Examples of UPLC chromatograms.A. Identification of PEN (shown by red arrow) in the glucosylated human cortical bone samples. B. Identification of PEN (shown by red arrow) in the ribosylated human cortical bone samples. C. The UPLC chromatogram with the peak of ProOH (shown by red arrow) used for determination of collagen contents. Similar amounts of the samples were injected to the column. Notably, the chromatogram obtained from the analysis of the ribosylated sample contains several peaks that are not present in the glucosylated sample.

Mentions: Before the UPLC analysis, each hydrolysate was dissolved in 1% n-heptafluorobutyric acid (HFBA). PEN was separated using an Acquity UPLC machine (Waters Corp., Milford, MA, USA) equipped with the reverse-phase Acquity UPLC HSS T3 column (1.8 μm; 2.1 x 100 mm). The column flow rate and temperature were 0.400 ml/min and 40°C, respectively. Solvent A contained 0.06% HBFA in 18 ohms pure water, and solvent B was composed of 50: 50 (v: v) mixture of solvent A: acetonitrile. Prior the use, the column was equilibrated using 10% solvent B. Gradient of 10 to 50% of solvent B (from 8 to 20 min) was used for the separation of PEN. The elution of PEN was monitored for fluorescence emission at 385 nm after excitation at 335 nm (Fig. 2A and B). PEN was quantified using a standard curve.


Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

Sroga GE, Siddula A, Vashishth D - PLoS ONE (2015)

Examples of UPLC chromatograms.A. Identification of PEN (shown by red arrow) in the glucosylated human cortical bone samples. B. Identification of PEN (shown by red arrow) in the ribosylated human cortical bone samples. C. The UPLC chromatogram with the peak of ProOH (shown by red arrow) used for determination of collagen contents. Similar amounts of the samples were injected to the column. Notably, the chromatogram obtained from the analysis of the ribosylated sample contains several peaks that are not present in the glucosylated sample.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4334514&req=5

pone.0117240.g002: Examples of UPLC chromatograms.A. Identification of PEN (shown by red arrow) in the glucosylated human cortical bone samples. B. Identification of PEN (shown by red arrow) in the ribosylated human cortical bone samples. C. The UPLC chromatogram with the peak of ProOH (shown by red arrow) used for determination of collagen contents. Similar amounts of the samples were injected to the column. Notably, the chromatogram obtained from the analysis of the ribosylated sample contains several peaks that are not present in the glucosylated sample.
Mentions: Before the UPLC analysis, each hydrolysate was dissolved in 1% n-heptafluorobutyric acid (HFBA). PEN was separated using an Acquity UPLC machine (Waters Corp., Milford, MA, USA) equipped with the reverse-phase Acquity UPLC HSS T3 column (1.8 μm; 2.1 x 100 mm). The column flow rate and temperature were 0.400 ml/min and 40°C, respectively. Solvent A contained 0.06% HBFA in 18 ohms pure water, and solvent B was composed of 50: 50 (v: v) mixture of solvent A: acetonitrile. Prior the use, the column was equilibrated using 10% solvent B. Gradient of 10 to 50% of solvent B (from 8 to 20 min) was used for the separation of PEN. The elution of PEN was monitored for fluorescence emission at 385 nm after excitation at 335 nm (Fig. 2A and B). PEN was quantified using a standard curve.

Bottom Line: Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors.Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content.Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, United States of America.

ABSTRACT
To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs) at the levels that corresponded to approx. 25-30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation) or ribose (ribosylation). Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN) in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women). More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples). Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar supplementation in food and drinks.

Show MeSH
Related in: MedlinePlus