Thermal stability of collagen in naturally ageing and in vitro glycated rabbit tissues

Abstract

The aim of the work was to compare glycation-related changes in thermal denaturation of collagen in naturally ageing and in vitro ribosylated tissues. Samples of cornea, meniscus and Achilles tendon from young adult and from ageing rabbits were compared. Moreover, in vitro glycated samples (ribose, 100 mg mL -1 , 14 days) were prepared for both age groups. Collagen in tissues was characterized in terms of thermal denaturation parameters obtained from differential scanning calorimetry. The level of pentosidine and other fluorescent advanced glycation end products (AGEs) in the papain-digested tissue samples was evaluated using spectrofluorimetry (k ex/em : 335/385 and 370/440 nm). In naturally ageing tissues, changes in properties of extracellular matrix collagen expressed in terms of parameters of thermal denaturation and fluorescent AGEs levels were tissue dependent and were related to differences in organization of matrix components. No signs of increased level of AGEs were found in the naturally ageing cornea, unlike in the tendon and meniscus. In vitro ribation proved by gains of fluorescent AGEs affected thermal stability of collagen in all tissues, both in young adult and in the ageing ones. The effects of ribation were considerably greater than the effects of natural ageing. The increase in denaturation temperature was similarly strong in all tissues and did not correlate with the increase in fluorescent AGEs. As a conclusion, parameters of collagen thermal denaturation are tissue and age dependent and an amount of fluorescent AGEs is not the only determinant of increasing thermal stability of glycated collagen.

Thermal and vibrational biomarkers of porcine oral mucosa

“…The characteristic denaturation temperatures T ONSET , T MAX , T MID , T END well fit with the denaturation temperature range recorded for hydrated collagenic tissues such as pericardium tissue [49,50], skin [48,62]. ΔT 1/2 values are found in the same range as complex collagenic tissues, namely cornea and meniscus [59]. Another important thermal parameter of the denaturation is ΔH, the area under the endotherm.…”

“…As defined in previous studies [26,45,[57][58][59], the primary characteristics of the denaturation peak are T ONSET , T MAX , T MID , T END and ΔT 1/2 . These five values of temperature are necessary to describe the distribution of the complex denaturation endotherm.…”

“…T MID is the temperature at which 50% of collagen is denatured (determined from the integral of the denaturation endotherm), and it varies with the amount of the different cross-links in collagen. ΔT 1/2 corresponds to the half-width of the denaturation endotherm and can be used to evaluate the cooperativity of the transition [59][60][61]. Mean values of the denaturation temperatures and half-width for mandible and maxilla are reported in Table 2.…”

Effect of Soybean Meal Substitution by Raw Chickpea Seeds on Thermal Properties and Fatty Acid Composition of Subcutaneous Fat Tissue of Broiler Chickens

“…It is a fast and environmentally friendly technique, as it does not require the use of chemical reagents. In medical sciences, there are reports showing that DSC analyses can complement histological or biochemical analyses, both in experimental works [18,19] and, potentially, in diagnostics where it has been acknowledged as a novel tool for diagnosing and monitoring several diseases [20][21][22][23][24]. In recent years, DSC is also becoming a more widely used method for analyzing animal tissues and food of animal origin [25][26][27].…”

Probing the binding selected metal ions and biologically active substances to the antimicrobial peptide LL-37 using DSC, ITC measurements and calculations

“…In the presented work, two complementary techniques, namely differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC), have been employed to study physicochemical properties of the LL-37 peptide. These techniques are generally used for the characterization of the peptides in aqueous solution [12][13][14].…”