Effect of proteoglycans at interfaces as related to location, architecture, and mechanical cues

Journal Article · Thu Dec 03 04:00:00 UTC 2015 · Archives of Oral Biology

DOI: https://doi.org/10.1016/j.archoralbio.2015.11.021 · OSTI ID:1379121

Kurylo, Michael P. ^[1]; Grandfield, Kathryn ^[1]; Marshall, Grayson W. ^[1]; Altoe, Virginia ^[2]; Aloni, Shaul ^[2]; Ho, Sunita P. ^[1]

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1. Univ. of California, San Francisco, CA (United States). Dept. of Preventive adn Restorative Dental Sciences
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Foundry

Covalently bound functional GAGs orchestrate tissue mechanics through time-dependent characteristics. The role of specific glycosaminoglycans (GAGs) at the ligament-cementum and cementum-dentin interfaces within a human periodontal complex were examined. Matrix swelling and resistance to compression under health and modeled diseased states was investigated. The presence of keratin sulfate (KS) and chondroitin sulfate (CS) GAGs at the ligament-cementum and cementum-dentin interfaces in human molars (N = 5) was illustrated by using enzymes, atomic force microscopy (AFM), and AFM-based nanoindentation. Furthermore, the change in physical characteristics of modeled diseased states through sequential digestion of keratin sulfate (KS) and chondroitin sulfate (CS) GAGs was investigated. One-way ANOVA tests with P < 0.05 were performed to determine significant differences between groups. Additionally, the presence of mineral within the seemingly hygroscopic interfaces was investigated using transmission electron microscopy. Immunohistochemistry (N = 3) indicated presence of biglycan and fibromodulin small leucine rich proteoglycans at the interfaces. Digestion of matrices with enzymes confirmed the presence of KS and CS GAGs at the interfaces by illustrating a change in ti ssue architecture and mechanics. A significant increase in height (nm), decrease in elastic modulus (GPa), and tissue deformation rate (nm/s) of the PDL-C attachment site (215 ± 63-424 ± 94 nm; 1.5 ± 0.7-0.4 ± 0.2 GPa; 21 ± 7-48 ± 22 nm/s), and cementum-dentin interface (122 ± 69-360 ± 159 nm; 2.9 ± 1.3-0.7 ± 0.3 GPa; 18 ± 4-30 ± 6 nm/s) was observed. The sequential removal of GAGs indicated loss in intricate structural hierarchy of hygroscopic interfaces. From a mechanics perspective, GAGs provide tissue recovery/resilience. Our results provide insights into the role of GAGs toward conserved tooth movement in the socket in response to mechanical loads, and modulation of potentially deleterious strain at tissue interfaces.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1379121
• Journal Information: Archives of Oral Biology, Journal Name: Archives of Oral Biology Journal Issue: C Vol. 63; ISSN 0003-9969
• Country of Publication: United States
• Language: English