کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2144888 1548025 2013 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Advanced glycation end-products diminish tendon collagen fiber sliding
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
Advanced glycation end-products diminish tendon collagen fiber sliding
چکیده انگلیسی

Connective tissue aging and diabetes related comorbidity are associated with compromised tissue function, increased susceptibility to injury, and reduced healing capacity. This has been partly attributed to collagen cross-linking by advanced glycation end-products (AGEs) that accumulate with both age and disease. While such cross-links are believed to alter the physical properties of collagen structures and tissue behavior, existing data relating AGEs to tendon mechanics is contradictory. In this study, we utilized a rat tail tendon model to quantify the micro-mechanical repercussion of AGEs at the collagen fiber-level. Individual tendon fascicles were incubated with methylglyoxal (MGO), a naturally occurring metabolite known to form AGEs. After incubation in MGO solution or buffer only, tendons were stretched on the stage of a multiphoton confocal microscope and individual collagen fiber stretch and relative fiber sliding were quantified. Treatment by MGO yielded increased fluorescence and elevated denaturation temperatures as found in normally aged tissue, confirming formation of AGEs and related cross-links. No apparent ultrastructural changes were noted in transmission electron micrographs of cross-linked fibrils. MGO treatment strongly reduced tissue stress relaxation (p < 0.01), with concomitantly increased tissue yield stress (p < 0.01) and ultimate failure stress (p = 0.036). MGO did not affect tangential modulus in the linear part of the stress–strain curve (p = 0.46). Microscopic analysis of collagen fiber kinematics yielded striking results, with MGO treatment drastically reducing fiber-sliding (p < 0.01) with a compensatory increase in fiber-stretch (p < 0.01). We thus conclude that the main mechanical effect of AGEs is a loss of tissue viscoelasticity driven by matrix-level loss of fiber–fiber sliding. This has potentially important implications to tissue damage accumulation, mechanically regulated cell signaling, and matrix remodeling. It further highlights the importance of assessing viscoelasticity – not only elastic response – when considering age-related changes in the tendon matrix and connective tissue in general.


► We used methylglyoxal (MGO) treated rat tail tendon to study mechanical effects of advanced glycation end-products (AGE).
► We stretched MGO treated tendon under a multiphoton confocal microscope to characterize collagen fiber sliding and stretch.
► MGO treatment strongly reduced tissue stress relaxation.
► MGO treatment drastically reduced micro-scale fiber-sliding with a compensatory increase in fiber stretch.
► We conclude that the main mechanical effect of AGEs is a loss of viscoelasticity driven by loss of fiber–fiber sliding.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Matrix Biology - Volume 32, Issues 3–4, 24 April 2013, Pages 169–177
نویسندگان
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