Alteration of the bone tissue material properties in type 1 diabetes mellitus: A Fourier transform infrared microspectroscopy study

A new stable GIP–Oxyntomodulin hybrid peptide improved bone strength both at the organ and tissue levels in genetically-inherited type 2 diabetes mellitus

“…However, the 1338/Amide II ratio was unchanged between the three groups of animals. Although the significance of this ratio remains to be elucidated, it has been previously demonstrated that the 1338 cm -1 peak is greatly affected by collagenase treatment and seems to be related to collagen helical integrity in bone and other connective tissues [45,62,63]. Furthermore, collagen orientations was altered in salinetreated db/db mice and restored in GIP-Oxm-treated db/db mice as compared with controls and these results are in agreement with previous observations reported by others [64,65].…”

“…In the present study, collagen glycation has been reported as the ratio between the sub-band located at 1032 cm -1 over Amide I. This ratio has been demonstrated specific of collagen glycation as compared with the less validated 900-1200 cm -1 /Amide I that takes into account subbands representative of protein phosphorylation and glycosaminoglycans [45]. However, the 1338/Amide II ratio was unchanged between the three groups of animals.…”

“…The contribution of the embedding polymethylmethacrylate (pMMA) and water vapour were corrected for each spectrum prior to baseline correction. Individual spectra were then subjected to curve fitting after second derivative using a commercially available software package (Grams/AI 8.0, Thermofisher scientific, Villebon sur Yvette, France) as previously reported [45]. The evaluated IR spectral parameters were (1) mineral-to-matrix ratio which reflects the degree of mineralization of the bone matrix, calculated from the ratio of integrated areas of the phosphate 1, 3 band at 900-1200 cm -1 to the amide I band at 1585-1725 cm -1 [46]; (2) mineral maturity, which reflects the apatite size and perfection, calculated as the ratio of the relative intensity of subbands at 1020 and 1030cm -1 of the phosphate band [47]; (3) the carbonate to phosphate ratio, which reflects the carbonate content in bone and determined by the ratio of integrated areas of the 2 CO 3 2region (850-890cm-1) to the 1, 3 phosphate band (900-1200cm -1…”

“…) [47]; and (4) the collagen maturity index, determined as the relative ratio of subbands located at 1660 cm -1 and 1690 cm -1 of the amide I peak, was assessed [48]. Then, bone sections were demineralized with EDTA and reanalysed by FTIRM at the same location as described in detail elsewhere [45]. The collagen glycation index was investigated as the area ratio of the 1032 cm -1 subpeak over the amide I region.…”

Advanced Glycation Endproducts and Bone Material Properties in Type 1 Diabetic Mice

“…Accounting for bone tissue age is paramount as this ratio is very sensitive to tissue age variations[ 25 ]. In a recent report which included calcein labeling in type 1 diabetic (streptozotocin-injected TO Swiss) mice that underwent Fourier transform infrared microspectroscopy, Mieczkowska et al similarly found an increase in collagen glycation and in mature collagen cross-links as compared to controls [ 46 ]. In contrast to our results, however, they did not find a decrease in the mineral/matrix ratio.…”